NUTRITIVE VALUE OF SEVERAL FORAGE SPECIES AS MEASURED BY IN VITRO AND IN VIVO METHODS BY J. RAY INGALLS AN ABSTRACT OF A THESIS Submitted to Michigan State University in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Department of Dairy l96h ABSTRACT Pure stands of alfalfa, birdsfoot trefoil, brome grass reed canary grass and timothy were harvested in 1961 and 1962. Three cuttings of each species were available for the 1961 crop and only first and second cuttings for the 1962 crOp with the exception of timothy of which only first cutting was available for both years. The legumes contained up to 2-3 times more lig- nin than did the grasses. Lignin content of the forages was positively correlated withad.libitum dry matter intake by weth- ers. Growing wethers were used to measure ad lib. dry matter intake, % digestible dry matter, digestible dry matter intake, dry matter nutritive value indices and body weight gains. Dry matter intake by the wethers ranked the 1961 forages in the order of birdsfoot trefoil, alfalfa, brome grass and reed canary grass while the 1962 forages were ranked in the order of alfalfa, birdsfoot trefoil, brome grass and reed canary grass. Dry matter ks takeof first and second cut forages were similar. Dry matter digestion coefficients were different for specific forages but when all cuttings and both years were considered, there was no difference in dry matter digestion coefficients for the different forage species. Digestible dry matter intake and nutritive value indiced followed a trend similar to that of dry matter intake for the different forage species. Weight gain was positively corre- 1ated to dry matter intake/cwt, digestible dry matter intake/cwt, 11 iii dry matter nutritive value indices and nutritive value indices while dry matter digestibility was not related to dry matter intake/cwt or body weight gain. However, the product of dry matter digestibility and dry matter intake resulted in a larger correlation coefficient with weight gain than did either individ- ually. Regression equations for nutritive value indices, dry mat- ter nutritive value indices and digestible dry matter intake on body weight gain were about equal in precision of predicting weight gain. The standard error of estimate were such that only large differences in forage nutritive value could be differen- tiated. Dry matter digestion coefficients, dry matter intake, di- gestible dry matter intake, dry matter nutritive value indices and weight gains by rabbits were not related to similar values determined by sheep. However, dry matter intake, digestible dry matter intake and dry matter nutritive value indices determined by sheep and rabbits were positively related to similar values determined by heifers. Dry matter disappearance of the forages was measured by use of an in vitro fermentation method over several time inter- vals. Initial in vitro dry matter disappearnce was slower for the grasses than for the legumes. Dry matter disappearance after a six hour fermentation period was correlated to dry matter in- take, digestible dry matter intake, dry matter nutritive value indices, nutritive value indices and body weight gains while iv 36 hour dry matter disappearance was correlated to in vivo dig- estion coefficients of dry matter and enerSY. Dry matter disappearance after a 6 hour fermentation period was effective in predicting the nutritive value of forages when the forages had a large range in nutritive values. Nethers receiving experimental forages were slaughtered and their rumen contents examined to ascertain the relation- ship between rumen contents of dry matter, fiber or lignin and intake. Rumen digests from sheep receiving the legumes contain- ed larger amounts and a larger percentage of ftcwr, and lignin than those receiving brome grass or reed canary grass. With the specific forages studied, lignin content of the forages or total intake of fiber and lignin did not appear to limit con- sumption. The relation between amount of dry matter in the rumen and ad lib. intake appeared complex and indicated there probably were other factors playing a role in controlling ad lib. intake. Bumen retention time of dry matter was about 0.6 days for the legumes and one day for the grasses. Bumen retention time of lignin was greater than that of fiber, which was greater than that of dry matter. As dry matter, fiber and lignin intake increased, retention time of each constituent decreased. Fur- ther studies will be necessary on the above relation to separate cause and effect. Digests from sheep fed legumes vs grasses contained a higher concentration of butyrate with no significant differences in acetate or propionate concentrations. NUTRITIVE VALUE OF SEVERAL FORAGE SPECIES AS MEASURED BY IN VITHO AND IN VIVO METHODS By LQ/ <7 ) J? RAY INGALLS A Thesis Submitted to Michigan State University in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Department of Dairy 196k BIOGRAPHY Jesse B. Ingalls was born in Randolph, Vermont on April b, 1936. He received his.first four years of elementary edu- cation in Tilton, New Hampshire; the fifth year in Canaan, New Hampshire, and the last three years at East Haven, Vermont. He graduated from Lyndon Institute at Lyndonville, Vermont in 1954 and entered The University of Vermont from which he graduated in June 1958, receiving the degree of Bachelor of Science with a major in Animal and Dairy Husbandry. In July, 1958 he re-entered The University of Vermont as a graduate research assistant in the Animal and Dairy Husbandry Depart- ment, majoring in Animal Nutrition and received his Master of Science degree in June, 1960. In August, 1960 he entered Michigan State University as a graduate research assistant in the Dairy Nutrition Department as a candidate for the degree of Doctor of PhilOBOphy. vi ACKNOWLEDGEMENTS The author wishes to express his sincere appreciation to Dr. J. W. Thomas for his assistance and guidance in carrying out this research and preparation of the thesis. The author also wishes to thank all members of the Dairy Department for their assistance and guidance. The author is indebted to Dorothy Carpenter for carry- ing out much of the laboratory analysis, to Dr. J. Benne for doing some of the forage analysis, to Dr. H. Tesar and the Crop Science Department for making the hays available, to Ralph Reid, Dale Bauman and other students who performed much of the physical labor. A sincere thank you to my wife Ann for her encouragement and many hours of unselfish help. vii TABLE OF CONTENTS INIPRODUCTIONOOOOOOOOOO ...... 0.. 00000000 O 0000000000 REVIEW OF LITERATUREOOOOIOOOO ....... cocoon-00000000000 Nutritive Value of Different Forage Species........ NUtritlve value Index (NVI).oooooeooeeo000000000000 Rabbits as Pilot Animals in Forage Evaluation...... Regulation of Forage Intake.................. ..... . Relation Between Gut Contents and Feed Intake Of BuminantsOOQOOOOQQOOOOOO00.000000000000000... Factors Affecting Reduction of Rumen Fill....... Rate of Passage.............................. Forage DigestibllityfloOOOOOOOOOOOOOOOOOOOO... Forage Degradation Rate...................... Effect of Urea, Thyroxine, or Limited Water on D1g88t10n and IntakeOOOOOOOOOOOO00.0.00... PalatabilityOOOO00.0.0.0...OOOOOOOOOOOOOOOOOOOI. ngnin asaMarkerOOOOOOOOOOOOOOOOOOOOOO...0.0.0... EXPERIMEIqTAL PROCEDURESOOOOOOIOOO.IOOOOOOOOOOOIOOOOOOC Forages - 1961 cropoeoocoocooooooooooooooooooooooeo Forages - 1962 CrOpgoQOOQQOOQOoococo-00000000000000 Sheep Trials - 1961 Cr0p........................... Sheep Trials-1962 crOPCOCOOOOOIOOOOOOOOOOOOOOOOOO Sheep DigeStion Trials-O...OOOOOOOOOOOOOOIOOOOOOOOO Rabbit TrialBOOOQQoooeooeoocoe000.0.00000000000000. Dairy Haifa? Trials - 1961 crOPOIOOOOOOOOOOOOOOOOO. In Vitro Fermentations - 1961 Forages.............. In Vitro Fermentations - 1962 Forages.............. viii Page Slaughter Trials _ 1961 CPOPOOOOOOOOOOO0.0.0.0000... 63 Slaughter Trials - 1962 crOPOOOOOOOOOOOOOO0.0.0.0... 6n BESULTSOO...000000....000000000000coo-0000.00.00.coco-o 68 Forages............................................. 68 Sheep Performance................................... 74 Heifer Performance.................................. 88 Rabbit Performance.................................. 90 Comparisons of ReSponses of Various Forages by Grow- ing Rabbits, Sheep and Dairy Heifers................ 93 In Vitro Fermentation Trials........................ 100 Slaughter Trials 1961 and 1962. O O O O O I O O O O 0 O O O O O O O O O C 116 DISCUSSIONOOOOOOOOOOO0.0.000000000000000000000.00...... 1&2 Comparative Responses of Sheep When Fed Various Fbrage Species and Cuttings......................... lug Comparative Responses by Sheep, Heifers and Rabbits. 151 In Vitro Fermentation vs. Animal Performance........ 155 Slaughter Trials.................................... 161 16'7 SUMMARYCOOOCOOOOOOOOOOOOOOOOOIOOOOOOOOOO000.......00... ‘ LITERATURE CITEDCOCOOOOOOOOOOOOOOOOOOOOCOOOOOOOOOOOOOOO 172 APPENDIXOOOOO0.0.0.0....OOOIOOOOOOOOOOCCCOCO0.00.000... 197 TABLE 10 ll 12 13 LIST OF TABLES 24-hr Digestible Energy Intake from Forages..... Dry Hatter Yields of Pure Stand Forages (1961 crop).OOOOCOOOOOOOOOOOOOOOOCCOOOO0......00...... Chemical Analysis of Experimental Forages (1961 and 1962 crop).OOCCOOOOO0.0000IOCOOOOOOOOOOOOIOC Fiber and Lignin Content of 1961 Forages as Determined by Van Soest......................... Simple Correlations Between % Digestible DH and DH Intake by Sheep vs % Fiber and Lignin Con- tent Of Forages...0.0.0...COCOCCCCOCOOCOOCOCCCOO Several Criteria Used to Evaluate the Experi- mental Pure Stand Forages (Sheep 1961 CrOp)..... Several Criteria Used to Evaluate the Experi- mental Pure Stand Forages (Sheep 1962 Crop)..... Several Criteria Used to Evaluate to Experi- mental Pure Stand Forages (Sheep 1961 and 1962 Crap Combined).................................. Dig. Organic Hatter, Estimated TDN, Dig. Energy of 1961 and 1962 Pure Stand Forages as Deter- mined by Sheepoooooocooooooo0.000000000000000... Simple Correlation Coefficients of Several Cri- teria Used to Evaluate Forages (Sheep).......... Regression Equations for Estimating Live Weight Gains from Dig. DH Intake/cwt. and In Vivo NVI and for Estimating In Vivo NVI from Dig. DH Intake/cwtOOOOOOOOOOOIIOOOOOOOOOOOO000.00.00.00. Comparative Forage Consumption (DH) by Three Different Animal SpecieBOOOOOOOOOOOOOOOOOOOOOOOC Dry Hatter Digestion Coefficients for Pure Stand Forages by Sheep and RabbitSOOOCOOOO00.00.00.000 2mm 23 51 69 71 73 75 76 77 81 84 89 91 9a 1h 15 l6 17 18 19 20 21 22 23 2H 25 26 27 xi Relative DH Intake of Pure Stand Forages by Three Animal Species........................... Digestible DH Intake of Pure Stand Forages by Three Animal SpeC1eBOOOIOOOOOOOOOOOOOOOOOOOOOO. NVI Values for Pure Stand Forages by Three Animal SpecieSIOOOOOOOOOOOIOOOOOOOIOOOOOCCOOOOO Weight Gain of Sheep, Heifers and Rabbits Fed Pure Stand ForageSOOOOOOOOOOOOOOOOOOOOOOOOOOOOO Simple Correlations Among Several Criteria Used to Evaluate Nutritive Value of Forages by Three Animal SpecieS........................... Simple Correlations Between In Vitro Fermen- tation DH Disappearance and Sheep Performance DataOOCOOCO0.0.0.000...OOOOOOOCOOOOOCOOO...C... Regressions of Forage Intake, Digestibility and In Vivo NVI on In Vitro DH Disappearance (1961 and 1962 Forages).............................. DH Disappearance When Buffer was Substituted for Rumen Inoculum and Incubated for 3 Hours....... Simple Correlations Between DH Disappearance Due to Rumen Inoculum and In Vivo DH Intake, DH NVI, and weight GainOOO.0......OOOOOOOOOOOOOOOOOOOOO DH Disappearance When Buffer was Substituted for Rumen Inoculum and Incubated for Various Times Using Brcme II - 1962 Crop............... DH Disappearance (i) When Sulka Flock was Used as Substrate in Usual Procedure................ DH Disappearance of Standard Alf. Using Differ- ent Volumes of Both Settled and Non-Settled Rumen Inoculum................................. DH Disappearance of Two Substrates Using 60 m1 of Non-settled and 24 m1 of Settled Rumen Inoculum....................................... Total and Non-filterable DH in Settled and Non- Settled Rumen Inoculum......................... 95 96 97 98 101 103 108 111 112 113 114 115 115 116 xii TABLE PAGE 28 Daily DH, Dig. DH, Fiber and Lignin Intake/cwt by Hethers (Avg. for 3 Days Prior to Slaughter.... 118 29 Percent DH, Fiber and Lignin Content of Rumen Digesta from Wethers Fed the Pure Stand Forages... 121 30 Rumen Content of Wet Digesta, DH, Fiber and L1gnj.p/0‘it0f SheePOOOO0.0000000000000000.00.0.... 123 31 Simple Correlation Coefficients Between Intake of DH and Rumen Contents of DH, Fiber, and Lignin. 126 32 Rumen Retention Time of DH, Fiber, and Lignin..... 128 33 Average DH and Fiber Disappearance in the Rumen and Lower Large (L.L.) Intestine as Determined by Lignin Ratio Technique and Compared in Total COlleCtion Trials...COO...OOOOOOOOOOOOOOOOOOOOOOO. 132 34 Total Castro Intestinal (GI) Tract Contents and Rumen Contents as a % of the Total................ 135 35 Rumen Contents pH at Time of Slaughter............ 138 36 VFA Content of Rumen Digests at the Time of Slaughtereeoo0.0.0.000...cocooooooooeoooooooono... 1’40 FIGURE \IO\U\¢’WNH LIST OF FIGURES Daily DH Intake (lb/cwt/sheep).................. Regression for Gain and Dig. DH Intake.......... Regression for Gain and In Vivo DH NVI.......... Regression for Gain and In Vivo NVI............. Regression for Gain and Dig. Energy Intake...... Regression for Dig. DH Intake and In Vivo NVI... In Vitro DH Disappearance of 1962 First Cutting Forages.00000.0.00000000000000000000000000000... In Vitro DH Disappearance of 1962 Second Cutting ForageSOOOOOOOOOOOOOOOOCOCOOOOOOOOOOOOOOOOOOIOO. xiii EASE 79 85 85 86 87 87 105 106 APPENDIX TABLE II III IV VI VII VIII IX XI XII XIII XIV LIST OF APPENDIX TABLES Daily DH intake of forages by sheep throughout the experimental period....................... Digestible organic matter, digestible energy and estimated TDN values for pure stand for- ages for each individual sheep by period...... Daily DH intake/cwt of forages by individual SheePOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOCOI Digestible DH % of forages by individual sheep Daily digestible DH intake/cwt of forages by 1nd1V1dual sheePOOOOOOCOOOOOOOCOOIOOOOOOOOOOO. Daily digestible energy intake/cwt of forages by individual sheep........................... In vivo DH NVI values for the pure stand for- ages as determined by individual sheep........ Weight gain for sheep receiving the eXperi- mental forageSOOCOOOOOOOOOOOOCOCOOOOOOOOOOOOCO Digestible DH % of pure stand forages based on intake 48 hours prior to feces collection..... Average sheep weight gain on 1962 pure stand forages for different portions of the eXperi- mental periOdooeaooeocoococo-cocoooooooeoeooeo In vivo NVI for experimental forages as deter- mined by individual sheep..................... Sequence of individual sheep on the experi- mental forageSOOOOOOOOOOOOOOOOOOOOO00.0.0.0... Analysis of variance of combined 1961 and 1962 sheep performance when receiving first cutting foragesooec000.00.00.00...oooeoeoeoooooeoeoooc Analysis of variance of combined 1961 and 1962 sheep performance when receiving second cutt- ing forage...0.0.00.0...000OIOOOOOOOOIOOOIOOOO xiv 197 199 201 202 203 20h 205 206 207 207 208 209 210 212 XV APPENDIX TABLE PAGE XV Analysis of variance of combined 1961 and 1962 sheep performance when receiving first and second cutting foresee........................ 2lh XVI Daily DH intake of pure stand forages by indi- V1dual rabbitSCIOOOOOO.OOOOOOOOOOOOOOOOOOOOOOO 216 XVII Digestible DH % of pure stand forages as deter— mined by individual rabbits................... 216 XVIII DH NVI values for pure stand forages as deter- mined by 1nd1V1dual rabbitsooooooo00.0.0000... 217 XIX Body weight gain of individual rabbits receiv- ing foragesOOOOOO0.000000000IOCOOOOOOO0.0.0... 217 XX Daily DH intake/cwt of pure stand forages by individual heifers............................ 218 XXI DH NVI values for pure stand forages as deter— mined by 1nd1V1dual heifers...coco-0000000.... 218 XXII Body weight gain of individual heifers receiv- ing pure stand foresee........................ 219 XXIII Average in vitro DH disappearance of pure stand forages with standard errors and % coefficients Of valatlon.........I.OOOOOCOCOCOCCOOOCOCCOC. 220 XXIV Analysis of variance of in vitro DH disappear- ance Of pure Stand forageSoQOoeeeeo000000-0000 222 XXV DH disappearance (%) of alfalfa hay standard.. 223 XXVI Rumen inoculum DH and non-filterable DH from in vitro fermentation blanks.................. an. XXVII DH disappearance of forage substrates due to buffer and due to rumen inoculum (difference between DH disappearance with buffer and total in vitro DH disappearance).............. 225 XXVIII DH and fiber digestion in the rumen and lower large intestine as determined by the lignin ratio tecnniquOOOOOOOCOO0.0.0.0.....0...0..O... 226 INTRODUCTION Forage is an important feed source, more so in some coun- tries and certain areas of countries than others. According to Crampton g; g1, (66), in North America, forage makes up 65%, 55% and 90% of the feed requirements for beef, dairy cattle and sheep, respectively. In Holland over 50% of the crop land is in grass and over 70% of the grass is harvested by direct grazing. Hardison (112) stated that 75% of feed for ruminants came from forage. In corn growing areas of the U.S., corn is replacing more and more of the grass in livestock rations. This will probably be true as long as this country has an excess of food for human consumption. But as the United States becomes more populated, grass may become a more important source of animal feed and grain may be used predominantly for human con- sumption. Nutritionists have worked for many years on forage qual- ity in relation to its productive energy value when fed to live- stock. Of all the #000 or so feeds studied, forages are still the most difficult to describe or evaluate as to their nutritive value. Throughout this thesis the term nutritive value will be used in reference to animal reSponse in weight gain or milk production resulting from feeding an individual forage. A great deal of interest has developed in the study of forage Species and varieties in relation to animal response. Reid g§_§;,(21#,230) reported there was little difference in 4 1 digestibility of first cut forage species harvested on the same calendar date and that the legume: grass ratio had little effect on animal response. However, Hinson.§§,gl. (179) reported a difference in digestibility of forage species and varieties. Hany methods such as federal grades, visual examination, leaf content, date of harvest and many chemical analyses incl- uding lignin and fiber have been studied and used for evaluat- ing forages as a source of energy. None of these methods has been entirely successful. A recently developed in vitro fer- mentation method was highly correlated with in vivo digestion data. However, digestibility of a forage without intake is of little value in predicting animal performance. Plant breeders are in need of a method to evaluate forages that re- quires only small samples and one that will indicate small differences in animal response. Recently Crampton and coworkers (67) have proposed Nu- tritive Value Index (NVI) as a method of expressing the nutri- tive value of a forage. Since this is the only method proposed that takes into account forage intake as well as digestibility, the present study was undertaken to further investigate this method. Growth of laboratory animals on forages has been en- couraging enough to warrant further study; however the relationship between laboratory animal response, large animal response and NVI values are not known. Plant breeders at present have to work by trial and error in the development of forages that will be consumed in large quantities by ruminants. One of the reasons for this has been that the factors controlling forage intake have not been de- fined or delineated. There are several theories pertaining to the control of forage consumption by ruminants. The rumen load theory presented by Crampton gt g1, (67) appeared to have a logical basis to explain and relate intake of defined for- ages. Animal nutritionists and plant breeders would make more progress in selecting desirable forages for ruminants if fac- tors controlling forage intake were known. Economical animal production on high roughage rations requires large dry mat- ter (DH) yields of forage per acre, forage with high energy concentration and a forage that will be consumed in large quan- tities. REVIEW OF LITERATURE Nutritive Value of Different Ferage Species I A great deal of work has been done on chemical composi— tion and digestibility of forages and different forage Species. This work is of limited value unless it is also related to intake of forage and the resulting animal production. Acceptable work studying intake and animal production on some of the more com- mon forage species is not available. The work that has been reported is in disagreement as to the effects of forage Species on digestibility, intake and production. Reid g3 31. (214,230) reported that digestibility of a forage was highly correlated to date of harvest. He found little difference in digestibility of 8 different forage spec- ies and many mixtures harvested on similar calander dates. Newlander §t_§l. (189) found little difference in digestibility of early cut alfalfa and timothy hays. Other workers have reported little difference in the gross energy value of diffe- rent forage Species (l,7,8,94,269). Swift §§,§l, (245,246) reported that Kentucky bluegrass, orchard grass, brome grass, and timothy had TDN values of 71.4, 68.6, 69.4 and 60.6, reSpectively, when harvested at the same physiological stage of maturity (head emerged from the boot but not expanded). When these forages were compared u on the basis of calander date at harvest, a much smaller dif- ference in digestibility between Species was evident. Other workers have indicated differences in digestibility of the five forage species that were used in the present study (22, 25,60,122,l64,l74,l78,179,245,246). Hinson g§_§l. (178,179) reported that digestibility is more related to stage of maturity than calendar date of cutt- ing which is in agreement with Spahr et al. (236) and Baum- gardt (25), but in disagreement with others (58,114,230,245). When out at the same stage of physiological maturity there still appear to be differences in digestibility of the dif- ferent forage Species (25,164,174,l78,l79). Explanations vary for the observed differences in gg_lg_, consumption of alfalfa, birdsfoot trefoil, brome grass and reed canary grass. In some cases the differences in consump- tion may be due to lack of a common basis such as calendar cutting date or stage of maturity when harvested. However Spahr £2.31. (236) found a higher intake of mixed hay (a1- falfa-clover-timothy) than of orchard grass whether compared on calendar date of harvest or on stage of maturity. The difference in digestibility and milk production disappeared when based on stage of maturity rather than date of harvest (223). Gordon g; g1. (101) reported no difference in con- sumption when alfalfa containing 10% timothy was fed in com- parison to pure alfalfa. Also, Heigs and Converse (171) reported that alfalfa plus timothy hay was consumed at a rate 30% greater than alfalfa alone. Pratt §§_§l. (206) allowed heifers free access to alfalfa and timothy. During the first half hour after feeding, heifers spent 23% of their time eat- ing timothy and 77% eating alfalfa and at the end of a week the heifers had consumed 82% alfalfa and 18% timothy. How- ever, the timothy hay was of low quality. HcCall 22 gl. (164) compared several forage species har- vested at the same stage of maturity. Brome grass appeared to be unpalatable but had dry matter (DH) digestion coeffic- ients of about 45% while the other forages had values of 50- 605. Reed canary grass is generally considered rather low in palatability. Arny (9) reported that the consumption rate of this grass was lower than alfalfa, equal to timothy and more than a wild hay. These workers found dairy cows required more time to become accustomed to canary grass than the other species studied. When switched from alfalfa to canary grass their consumption drOpped 50% and then increased, but never to the previous level when on alfalfa. Fuelleman and Burlison (98) reported that brome grass was very palatable and that a canary grass pasture was unpalatable. Garrigus and Rusk (99) compared brome grass and canary grass pastures and found that steers would eat the canary grass only if forced to do so. Fillies consumed 26.7 lbs. of prairie hay and only 19.3 lbs. of canary grass (11“). Early work indicated that timothy hay would not main- tain milk production as well as alfalfa (170). This early difficulty with timothy hay was probably due to late harvest- ing and a lack of vitamin A. Salisbury and Morrison (224) fed grain, Silage and 10 1b of either timothy or alfalfa hay to two groups of 19 cows and found no difference in milk produc- tion. Holdaway g; 3;. (122) fed alfalfa or timothy in equal amounts with grain to dairy cows. The timothy was lower in digestibility than the alfalfa but milk production per 1b of nutrient intake was equal. Huffman §£_gl. (125) found that milk production remained the same when boot stage timothy replaced early-bud alfalfa hay in the ration. Archibald 3; al. (7) compared two second cutting hays harvested at the same stage of maturity (52% legumes and 45% grass or 5% legume and 79% grass). High yielding cows produced more milk on the mixed hay (52-45) where as the low producers yielded more milk on the grass hay. On the average the difference in pro- duction of cows fed the two foragestas not shown to be signi- ficant. These workers concluded that the "cow's ability as a converter of feed to food was of more significance that the type of roughage she gets." Hodgson and Knott (121) found milk production was a little higher on alfalfa than on mixed hay. Canary grass was found inferior to alfalfa for maintain- ing milk production (8). Van Arsdell 33.31. (258) reported that steers on canary grass pasture did not make satisfactory gains and were dull in appearance. Spahr g3 g1. (223) com- pared an alfalfa-clover-timothy mixture with orchardgrass that was harvested both at the same calendar date and at the same physiological stage of maturity. When both forages were harvested on the same calendar date milk production was great- est from cows receiving the alfalfa grass mixture. There were no differences shown in milk production when both for- ages were harvested at the same physiological stage of mat- urity. In both cases there was a difference in consumption of forage due to species. Weight gains of heifers were the same when receiving pure alfalfa or an alfalfa mixture with 10% timothy (101). Keith g; al. (137) compared alfalfa, alfalfa + 24% brome grass and alfalfa + 33% brome grass for growing and fattening of lambs. The forage was fed as a 50:50 mixture of hay and grain. There were no differences in weight gain. Blaxter and Wilson (31) stated that if one third of the ration was made up of grain any difference in response expected from an all forage ration would not be detectable. Northeastern dairy farmers for some time have preferred second cutting forage over the first cutting. There are prob- ably two major reasons for this preference: (1) good first cutting hay is more difficult to make with prevailing weather conditions, and (2) second cutting hay in the past has been harvested at an earlier stage of maturity. However, dairy farmers of New Mexico and Utah have thought that first cutting forage was higher in nutritive value than second cutting (53, 189). Second cutting in these areas has a more rank growth with more stems and a lower percentage of leaves (189). Early out first cutting forage has been reported to be higher in digestible dry matter than second cut forage (123, 217,230,269) while opposite results were noted by others (147,173). Reid et a1.(23o) and others (123, 269,272) have indicated that second cut forage decreased in digestibility with delayed harvesting but at a slower rate than first cutting forages. First cutting forage digestibility dec- reased at a rate of about 0.3 to 0.5 Percentage points per day with delayed harvesting (62,126,172,187,230). With a single forage species this may not be a linear decrease from early May to early July (187) and the extent of decrease is not the same every year (25). Colovas g; 3;.(60) reported that early first cutting timothy (64.5% dig. energy) was a better source of metabolizable energy than second cut clover (60.4% dig. energy). The ratios of steer weight gains were 10 100 to 75 to 110 for first, second and third cutting forages respectively (161). Several trials have been conducted comparing milk pro- duction when different cuttings of forage were fed. Carroll (53) compared first, second and third cutting early bloom alfal- fa for milk production. Average data for two years showed that consumption ranked the forages in the order of third, first, and second cutting respectively. Fat production ranked the forages in the order of first, second and third cutting. Efficiency of fat production was highest for second cutting forage. The authors concluded that second cutting forage was at least equal to first and third cutting forages for milk production. Porter §£_gl. (202,203) found that differences in consumption of first, second and fifth cuttings of early bloom alfalfa were not sig- nificantly different. However, cows consumed on the average of 0.5 to 1 lb more per day of first cutting forage and produced 0.18 to 1 1b more milk per day. The ranker growing second cutt- ing forage was equal to the more leafy first and fifth cuttings. Huffman‘gglgl. (125) indicated little difference in milk pro- duction when first cutting early bud alfalfa was replaced by second cutting early bud stage alfalfa. Hilk production in- Creased in one trial and decreased in four when second cutt- ing alfalfa replaced first cutting alfalfa, harvested at the same maturity stage. In all cases production from first cutt- 11 ing alfalfa was slightly higher than second cutting, but not significantly so. Loosli gtpgl.(152) compared early first cutting timothy with early bloom second cutting alfalfa and pre bloom second cutting trefoil. Percent digestible, dry matter, intake (lb/ day) and production of fat corrected milk (FCM) was 62.1, 64.3, 65.0% and 25.1 lb, 27.1, 23.7 and 3u.3, 33.9, 3n.o 1b for alfalfa trefoil and timothy respectively. The authors concluded there was no difference in animal performance when the animals received the above forages. Nutritive Value Index_(NVI) Crampton and co-workers at McGill University recently suggested nutritive value index (NVI) as a method to evaluate forages (66,67,69). The expression of NVI is a quantitative numerical term made up of the mathematical product of digest- ible energy concentration and relative intake of a specific forage per unit of animal metabolic size or weight in kilo- grams raised to the 0.75 power (Wt.kg°75). The idea of combin~ ing intake and energy concentration of a forage to indicate the forage's nutritive value was not new. Murry (188) in 1933 attempted to express nutritive value of feeding stuffs in a mathematical formula based on quality and quantity of intake. For some time other nutritionists have been aware of the import- 12 ance of forage intake along with energy digestibility. McCull- ough £2 31. (160,166,167) indicated that both total intake and energy concentration must be considered in describing the nutritive value of forages. Energy intake on an all roughage ration was the most often limiting nutrient for maximum pro— duotion. Crampton (69) calculated that only one out of eight forages were deficient in protein or calcium and one out of #0 were low in phosphorus. Reid §§_§1.(230) proposed that the main pur- pose of forage was to provide energy. Assuming other dietary conditions are adequate, then the two following assumptions appear warranted: a. Animal response is proportional to energy intake b. Energy intake equals dry matter intake times the energy concentration. Blaxter and co-workers (34) have shown that a 10; increase in energy concentration of a forage may produce a several fold increase in the energy available for production. icCullough (165) reported similar findings. Crampton and co-workers attempted to elucidate their concept of nutritive value index (NVI) by feeding pure stands of early bloom alfalfa, red clover, birdsfoot trefoil, brome grass and timothy in a chOpped and artificially dehydrated condition to ewes in a 5 x 5 latin square design and collect- ing animal performance data (1956). In 1957, early bloom and full bloom cuttings were made of both red clover and timothy 13 and fed to ewes in a b x h latin square design. The feeding periods for both trials were 21 days long. Data from the last eleven days of each period were used to determine volun- tary intake, weight gain and digestibility of the forages. Using the above data, the authors calculated the NVI values for each forage and related these to animal performance. Relative intake is a term applied by Crampton _e_t _a_1_. (67) to indicate intake of forage relative to a standard. Thus intake values of all forages could be expressed as a % of this standard value. Early cut, artificially dehydrated legume hays when fed to sheep resulted in maximum consumption of 80 t 10.5 .75) g per unit of metabolic size (Wt . This is equivalent 'kg to about 3 lb/lOO lb of body weight (cwt). The equivalent for dairy cattle would be 140 g per unit of metabolic size (65,66). Metabolic size was used to minimize the size effect on intake (67,1u5,155,221). A variation of 22% (52 - 109 lb) between body weight of sheep resulted in a 20% variation in forage consumption (67). This variation was reduced to lhfi when consumption was based on intake per cwt (67) or 13 to 10% when based on intake/Wt.kg'75 (3h,67). Dry matter intake and body weight were correlated (r = .75) while the correlation coefficient between body weight and intake/cwt was small (r = .21). Expressing intake per metabolic size eliminated the high correlation between body size and intake (r = .08). 10 Thus all relative intake values for sheep are relative to 80 grams of DM intake/Wt.kg°75 which was assigned a numberical value of 100. Relative intake (RI) was computed in the following manner: 1. Compute metabolic size as weight in kg‘75 for the sheep in question 2. Determige expected intake of standard forage (i.e. Wt.kg° x 80) 3. The observed intake of test forage is divided by expected intake and multiplied by 100. observed DM intake g HI = 80(Wt.kg'75) x 100 Nutritive value index (NVI) was then calculated by obtaining the product of relative intake (RI) and % digestible energy of the forage. Forages with a BI of 100 were found to be about 70% digestible resulting in an NVI of 70 (100 x 0.70). Multiple correlation and partial regressions (67) indicated that intake and digestible energy contributed 70% and 30% res- pectively to the final NVI expression. Byers 2L 2;. (00) found similar results. Crampton and co-workers (66,67,109) reported that NVI and weight gain had a higher correlation coefficient than intake and weight gain (r's about .9 vs. .5). One pound of gain in 11 days (.09 lb/day) reflected a change in NVI of 7 to 8 units. McCullough (165) reported that NVI adequately described the nutritive value of 3 silages in relation to 15 weight gains. Nutritive value index as presented above requires data on animal intake and digestibility of the forage. This requires much time and expense, and is of use only as a quantitative value for intake and digestibility of a forage already investi- gated. In recent years laboratory methods have been deve10ped to study forage digestibility. Many workers have shown signi- ficant correlations between in vitro fermentation or arti- ficial rumen data and in vivo digestibility (10,21,20,26,28, 01,02,58,59,81,82,116,131,132,l03,200,209,212,232,250). Some workers have used in vitro dry matter disappearance while others used in vitro cellulose digestion. The rate and extent of forage digestion have been studied by placing forage samples in semipermeable containers and placing them, through a fistula, into the rumen. Porcelain test tubes, bottles with semipermeable t0ps, semipermeable mem- branes, etc. have been suspended in the rumen for a period of time to study the rate and extent of forage degradation (91, 92,209). Semipermeable cloth bags, such as nylon, containing forage samples have also been suspended in the rumen (150,216, 259,260,279). The rumen is used as the incubator rather than a warm water bath as used with other in vitro fermentation methods. Dehority and Johnson (77) compared in vivo forage diges- 16 tibility with the amount of forage cellulose dissolved by cupriethylene diamine (CED). Cellulose dissolved by CED was correlated with in vitro cellulose digestion. CED soluble cellulose of grasses was closely associated with in vivo cellu- lose digestion and effective nutritive value index. The sol- ubility of alfalfa cellulose by CED did not follow a pattern similar to that of the grasses, indicating a possible diffe- rence in the chemical structure of grasses and legumes, how- ever preextraction with water increased the resulting relation- ships. Donefer gt 3;. (79,80) used various enzymes and solu- tions to digest or dissolve forage dry matter. Dry matter dissolved by potassium hydrogen phthalate, cellulase, cellulase plus pepsin, hydrochloric acid plus pepsin, and distilled water was correlated with nutritive value indices (r's of approxi- mately 0.9). Several different in vitro fermentation methods have been reported in the literature with many variations of each method. Some of the methods are indicated below. 1) Semipermeable membranes containing rumen inoculum plus substrate surrounded by artificial saliva have been used (105,228). 2) Continuous type fermentations are used where it is necessary to keep the fermentation culture alive and growing over a period of several days (70,111,200). 3) Probably the simplest method is to add 17 rumen microorganisms, a buffer solution and a small amount of substrate to a fermentation flask and then incubate the mixture for several hours. All the above methods have been used to study the degradation of forages by rumen microorganisms. Microorganisms taken from the rumen may be prepared in several ways for use in in vitro fermentation studies of for- ages. 1. Strained rumen juice is obtained by taking rumen contents directly from the rumen and squeezing out the juice by hand. This liquid is then strained through cheesecloth and used as the inoculum. 2. PhOSphate buffer extract is obtained by adding phosphate buffer to the pressed rumen pulp from above and then the pulp is repressed. This liquid extract is used as the inoculum. 3. (a) Resuspended ruminal microorganisms are obtained by centrifuging the inoculum obtained in the phOSphate buffer extract above. The sediment is then resuspended in phosphate buffer and is used as the inoculum. (b) Liquid as obtained in #1 above is centrifuged and the sediment resuspended in phosphate buffer. Quioke 23 filo (209) indicated that it made little diffe- rence in forage degradation which of the above methods were used. Shelton and Reid (232) found little advantage of using 18 the semipermeable membrane method over other in vitro fermen- tation methods to study degradation of forages. This is in agreement with work by El-Shazly g3 g1. (86) and Baumgardt g; .31. (20). Quicke E; El, (209) also indicated that filtered ru- men fluid was as good as other types of culture preparations for studying the degradation of forages. Some investigations have indicated that in vitro diges- tible dry matter determinations rather than digestible cellu- lose gave higher correlations with in vivo dry matter digestion (02,217) and smaller coefficients of variation (01,02). Ram- aiak and Blosser (212) reported in vivo digestible dry matter was more highly correlated to in vitro cellulose digestion than to in vitro dry matter digestion. However, the literature as a whole indicates that both in vitro dry matter and cellu- lose digestion compare equally well with in vivo animal data. Crampton and co-workers (81,82) utilized the in vitro fer- mentation method to study the relationship of in vitro diges~ tion of experimental forages to animal performance when fed the same forages. Cellulose disappearance was measured at inter- vals of 3,6,12,20, and 08 hours, and disappearance curves obtained were similar to those of Hershberger,g§,§l.(ll6). A delay or lag period in cellulose digestion was indicated for some forage species, especially the grass hays. Forage con— sumption (relative intake) was related to the 12 hour in vitro 19 cellulose digestion (r = .83). These data indicate that diges- tion occurring during the early portion of the in vitro fer- mentation might be useful in explaining differences in forage consumption. These authors reasoned that differences in early digestion occurring in the in vitro fermentation could relate to differences in forage consumption if the "rumen load" does control the level of forage intake (67). The relation of diges- tibility, rate of passage and rumen fill to intake are covered on pages 25-00. The length of fermentation time that gave the highest correlation with in vivo data has varied in literature reports. In vivo digestible energy was correlated with 20 hour in vitro cellulose digestion (r = .87) (6). However, Reid, §§,§;,(216) was not able to show a consistant relation between in vitro cellulose digestion and in vivo % digestible dry matter. Donefer g£_§1. (82), Baumgardt gt 3;. (20,26) and Reid g£_§l. (216) found no advantage in fermenting 08 hour rather than 20 hour. Johnson.§t_g;, (131) found that correlations between both 12 hour and 20 hour in vitro cellulose digestibilities and in vivo % digestible dry matter were similar. Bowden and Church (01) reported 08 hour incubation periods rather than 20 reduced within treatment variation. Length of incubation period may change correlations between intake and % digestible dry matter because these different in vitro methods may have 20 different coincidence times with in yiyo rumen phenomena. In vitro methods do not necessarily have to duplicate i vivo digestibility and intake by the animal. However, to be useful, _yg'!;§£g and in 1312 values should be related so that ;g zipgg values could be used to predict in vivo digestibility or nu- tritive value indices. Donefer §£_g;. (82) reported that either 12 hour cellu- lose digestion or the product of 12 and 20 hour cellulose digestion could be used to predict nutritive value index (NVI) (r = +.91 and + .89 respectively). The authors suggested that 20 hour in vitro cellulose digestion could be used to esti- mate in vivo dry matter digestibility and 12 hour in vitro cellulose digestion could be related to forage consumption. The product of cellulose disappearance at two different times during in vitro digestion may have advantages over using data from only one time, however present evidence to support this is not convincing. The regression obtained between NVI and 12 hour in vitro cellulose digestion (82) is given as: Y 08.0 + 1.310 (X - 02.8) where Y predicted NVI; and X = 12 hour in vitro cellulose digestion. The above regression was based on a limited number of forage species and observations. In later work (81) assuming homogen- 21 eity of regression coefficients, when ground and chOpped forage data were combined, the regression equation given to predict NVI of chOpped forage was: Y = ~3.5 + 1.23 X where Y - NVI and X = 12 hour in vitro cellulose digestion. Twelve hour in vitro cellulose digestion of ground forage resulted in predicted nutritive value indices (NVI) 10.9 units higher than chopped forage (81,109). There was a slight drOp in digestibility, but this was more than offset by inc- reased intake when the ground forage was fed to sheep. The following formula, compared to the one above, will allow one to compare the NVI of chOpped hay with those of ground hay: Y = -3.5 + 1.23 X + 10.9. There is no data comparing NVI for ground pelleted forage with other physical forms of forages. Crampton 2; El. found that with advancing maturity in timothy hay, intake and digestibility decreased thus resulting in lower nutritive value indices (NVI) (108,109). Many workers have shown that as a forage matures, its productive potential decreases. When forages have a large variation in gross energy, concentration NVI may not give a good indication as to the energy consumed (177). If intake per unit metabolic size and % digestible energy of two forages are similar, the resulting NVI would be the same. Gross energy content of these two forages could be different and the resulting diges- 22 ible energy intake very different. The usefulness of NVI would be extended if the gross caloric content of forage was known. Crampton g; g;. (65) found that gross caloric content of our common forages was 0.0 Kcal/g. According to the auth- ors when estimating 20 hour energy intake, a one tenth Kcal variation from 0.0 Kcal/g of forage will result in only a 2% error. NVI values can be used to determine 20 hour digestible energy intake if all forages are assumed to contain 0.0 Kcal of gross enerEY. The outline in Table 1 presents Crampton's ideas on how NVI could be converted to digestible energy intake and how in vitro data can be used to predict forage digestible energy yield to the animal (65,82). Rabbits as Pilot Animals in Forage Evaluation The use of laboratory animals such as rabbits to eval- uate forages could cut down time, expense and amount of feed necessary if the reaponse of small animals could be related to that of the large animal. Although the digestive system of the rabbit is quite different from that of ruminants, there are certain similarities. Rabbits have a large stomach with microbial action and a comparatively large large intes— tine (2) where microbial products are produced and because of cOproghagy, these products are made available for absor- ption (250). With the exception of crude fiber, rabbits have been reported to digest roughage nearly as well as other 23 TABLE 1. 20-hr Digestible Energy Intake 100 (intake/Wt.kg'75 (80 is replaced From Forage. . % dig.0f energy by 100 for NVI = 20-hr.dig. 1.25 (intake/Napg 80 cattle) .75)(% dig.0f energy) kcal intake/=Intake/Wt.kg'75(% dig.of energy)(€FOSS kcal/g) ’th . kg 0 75 20-hr dig. Kcal intake/= wt.kg°75/NVI 20-hr dig. Kca1.intake = from forage 20-hr. TDN intake from forage (lb) 0‘ II N Intake/Wt.kg:75(% dig.of energy)(gross Kcal/g) _7‘ 1.25 (intake7Wt.kg,.7§)(% dig.offienergy) gross Kcallg 1.25 = k 0 0 _ . 0 0 = ' ~ _ lf25 _ 3.5 for sheep, 07710 6.2 for cattle 20-hr dig.§ca1 intake from foragg = 2000 k (Wt.kg°75) Co+b(X) + cl 20 hr digestible Kcal.yield to animal from forage 12 hr lg vitro cellulose digestion 3.5 for sheep; 6.2 for cattle 3.5 general constant in NVI prediction equation for chOpped forage 1.23 regression of Y on X 10.9, to adjust NVI for larger intake if ground forage was fed. 24 domestic animals (264). The net energy derived from a rough- age was similar for rabbits and ruminants (68). Richards gt 3;, (218) in their review reported that Jarl (128) found a correlation between digestion by rabbits and bulls of -.65. He also reported that Watson 22.§l- (270, 271) concluded that rabbits and sheep were too different for one specie to be an indicator for the other. However, Crampton ethal. (7) reported that several workers found similar diges- tive abilities for steers and rabbits. Matrone §£_§l, (160) successfully used the rabbit in studying phosphorus levels in soybean forage. Richards gt a;, (218,219) compared rabbit and sheep digestion coefficients of timothy, orchardgrass, brome grass, alfalfa- brome mixture, and alfalfa when harvested at three stages of maturity and fed at a rate 10% below maximum consumption. The correlation coefficients between sheep diges- tible dry matter and rabbit digestible dry matter for grasses, legumes, and all hays were .85**, .97** and .47* respectively. Rabbits showed larger reductions in digestibility with delayed harvesting than did the sheep. Data comparing rabbit and ruminant growth when fed the same forage was limited. Crampton §t_§;, (70) used steers and rabbits to compare pasture at different periods throughout the summer. Rabbits digested dry matter 71 to 85% as effic- iently as did the steers. Trends in weight changes were similar for rabbits and steers. Work by Matrone gt a;. (160) 25 and the above work of Crampton g2 El- (70) indicate that rab- bit growth might be used to estimate the nutritive value of forages. Regulation of ForageiIntake Researchers have attempted for many years to explain the control mechanisms Operative in regulating intake of for- ages. Many theories have been proposed but no single theory adequately explains all differences in consumption. A few of the more popular theories proposed are listed below. 1. Thermostatic regulation 2. Lipostatic regulation 3. Other chemostatic regulation a. Lipid glucostatic regulation 5. Central nervous control 6. Physical regulation due to gut capacity Several reviews have recently been written on the sub- ject of food intake regulation in mammals based on the prev- iously stated theories (5,12,88,118,169,263). After reading the several reviews, the reader obtains the idea that not Just one, but probably several of these mechanisms do have some control of feed intake. The inter-relations among these mechanisms are not understood at present. This review of feed intake will deal only with ruminants and the proposed physical regulation of dry forage consumption. The above reviews adequately cover the different theories of intake regulation in respect to both monogastric and ruminant ani- 26 mals. Relation Between Gut Contents and Feed Intake of Ruminants. For some time workers have suggested that bulk in the diet of ruminants might have some affect on voluntary con- sumption. Bulk alone cannot regulate rate of consumption but the interaction of bulk with rate of passage, rate of degra- dation and digestion of forages could be especially important in the consumption rate by ruminants. If the above is true, the size of gut would effect intake. Workers have attempted to measure volume (IMO) and swelling (208) of feeds in rela- tion to the filling effects they might have. According to Balch and Campling (12), Kruger and Muller (1955) indicated that cows fed different hays ad libi- tum would eat to similar rumen-reticulo fill. Blaxter gt El, (35) by mathematical manipulation suggested that sheep ate to a "constant gut fill"; i.e. to a constant amount of dry mat- ter in the gut after a meal. Crampton gt.§;. (67) outlined the events in rumen digestion of animals maintained on an all forage ration as follows: "1. Recurring hunger is closely associated with and probably primarily determined by some specific degree of reduction of the rumen ingesta load. 2. Rumen load is reduced at varying rates that presumably are correlated with the rate of the degradation of its cellulose and hemicullulose content. 27 3. The rumen ingesta load will reach the degree of reduction at which hunger recurrs after time periods characteristic of the Specific forage involved." With the above in mind these workers presented the theory of reticulo-rumen load and recurring hunger. Animals on a for- age ration would eat to a certain rumen fill and hunger would reoccur at a time specific for the forage once the rumen load had been reduced to a certain level. Reticulo-rumen load is reduced by physical break down of particles, diges- tion, absorption and passage of the digesta to the omasum. Many workers have tried to determine what effect bulk in the rumen has on consumption of forage (3b,35,45,h8,u9, 96,157). Makela in 1956 (157) reviewed and studied the ques- tion of bulk in the diets of farm animals with Special ref- erence to ruminants. Physiological capacity or gut fill on ad lib. feeding as measured in slaughter tests was found to be lower than previously determined gut capacity as measured by adding water. Hay intake was reduced “-6 kg during the final stages of pregnancy. This was presumably due to space limitation in the abdominal cavity due to space occupied by fetus and fat. Up to 51.9 kg of fat was found in the abdom- inal cavity of cattle. According to Balch and Campling (12) Heeselbarth (1953) also suggested a decrease in consumption during late pregnancy. Other workers (103,215) reported that late pregnancy in sheep might limit intake. However, Balch 28 and Campling (12) reported that Broster (1960) found no de- pression of roughage intake during late pregnancy. Several workers (90,159,2b8) according to Balch and Sampling (12) reported that size of the abdominal fat depots resulted in a lower intake, thus suggesting that space in the abdominal cavity of ruminants might limit intake. Blaxter gt g1. (3U) fed high, medium, and good quality forage to Sheep. Gut "fill" was estimated by the method of Blaxter g; 3;. (35) to be 99.7, 100.0 and 9U.0 dry matter/ Wt/kg'73 for poor, medium, and good quality forage respec- tively. He concluded that the digestive tract contained about 100 g of dry matter/Wt.kg'73 irrespective of forage given. Although much indirect evidence indicated that physical fill may have limited intake, the direct evidence was lacking (12). Schalk and Amadon gt.gl. (229) found that removing swallowed food at the cardia caused most animals to increase their intake of alfalfa hay. Consumption was increased by removing digesta from the reticulo-rumen and decreased when hay was placed directly in the rumen. Campling and Balch (#8) studied the effect of reticulo- rumen fill on intake of hay by cows in several experiments. The hay was offered ad lib. once per day for 3-4 hours. Swallowed hay was collected at the cardia for 3 hours. Dur- 29 ing collection the cows consumed 76-96% of their normal in- take. Bemoving swallowed hay via a rumen fistula increased eating time from B-h hours to 6%-8 hours and total consumption increased 70-85%. When food was removed on experimental days, the cows did not cease to eat at the end of 3 hours as usual which indicates that the amount eaten was not due to habit but to a "full" rumen. This also would indicate that a cow does not stOp eating due to fatigue of jaw muscles or exhaustion of saliva. In one trial rumen contents were added and re- moved immediately before, during and after a meal. Digesta (50 lb) was removed from the rumen of one cow and placed in the rumen of another cow Just before feeding, just after feeding, one—half hour after feeding, l%-2 hours after feed- ing and half way between feedings. 0n the average, 50 lb of digesta contained 7.1 lb of dry matter and to compensate for this amount of digesta, the animal would have to change hay consumption by 8.U lb. Daily removal of digesta caused some increase in consumption but not equivalent to the amount removed. Removal of digesta just after a meal was more nearly compensated for by increased consumption than when the digesta was removed midway between meals. Adding digesta to the reticulo-rumen caused a decrease in consumption but not equivalent to the amount added. Again the compensation was greater when the digesta was added at or near the time of feeding. 30 Water-filled bladders were placed in the rumen of cows (0,85, and 100 lb). Voluntary intake decreased as the weight of water in bladders increased (.SU 1b hay/10 lb water). Direct addition of 100 lb water to the rumen did not affect intake. This is in agreement with work of Moore a g; 31. (181) and Hillman ggwgl. (119). Veltman (263) repor- ted that infusion into the rumen of up to 28 liters of sil- age juice per day caused a slight increase in consumption but infusion of 32 liters per day caused the cow to go off feed. Campling g£_gl. (#9) fed straw and hay in ad lib. or in restricted amounts to cows and measured reticulo-rumen contents just previous to feeding. The reticulo—rumen con- tained 165 lb (14.“ lb DM) and 128 lb (13.6 lb DN) of digesta when fed hay or straw respectively. A dry matter content difference of only 6% digesta found in the reticulo-rumen just after ad lib. feeding of hay or straw was 250 lb (27.2 lb DM) and 184 lb (20.2 lb DM) respectively. The difference in dry weight contents was 35%. This would indicate that forage was consumed at a rate resulting in similar fill just before feeding. One should however keep in mind that one of the forages was very low in protein (2.9%) and that the animals were only fed once a day. Freer and Campling (96) continued to study the effect of quantity of rumen digesta before feeding on intake of hay, 31 dried grass or concentrate. The reticulo-rumen contained b0% more digesta and an; more dry matter when fed hay rather than when fed dried grass. This difference was only 12 and 10%, respectively, after feeding. Thus roughage was consumed until the rumen reached about the same fill. When roughages were fed that had a disappearance rate from the rumen of greater than 18 lb/day, eating ceased when the reticulo-rumen con- tained 250 lb digesta or 35 lb of dry matter. Boughages with slower disappearance rates were eaten to a fill that left 19 1b of dry matter at the time of feeding. When concentrates rather than dried grasses were fed, the reticulo-rumen con- tained two thirds the amount of wet digests and one half the amount of dry matter both before and after feeding. The authors found an increase in concentrate intake of 84% and an increase in forage intake of 20% when feed was offered over a period of 24 hours rather than for one 5 hour feeding per- iod. It seems obvious that reticulo-rumen fill in the above experiment was not limiting intake when concentrates were fed ad lib. However, in this experiment the cows were consuming only 18 lb of grain per day. One wonders what the reticulo- rumen fill would be when cows are consuming 75 lb of grain per day (“3). Campling ggflgl. (#5) studied the effect of ad lib. and limited intake of long and ground pelleted forage on reticulo- 32 rumen fill. Intake was similar for both feeds. Just prev- ious to feeding, the reticulo-rumen, of cows fed long and ground pelleted hay contained 193.7 lb (19.6 lb DM) and 160.1 lb (18.2 lb DM) of digesta respectively. After feed- ing, 266.0 lb (34.6 lb DM) and 214.9 lb (31.6 lb DM) of digests was found in the reticulo-rumen of cows fed long and ground pelleted hay respectively. These workers suggested that ad lib. intake of ground pelleted forage was limited by rate of passage through the lower gut as restricted intake of the forages resulted in faster rate of passage with pelle- ted forage, than with long forage whereas with ad lib. feed- ing the rate of passage was similar for both forages. Other workers have indicated that food entering the intestine inhibits flow of digesta from the stomach (ll7,169,210,239). Waldo g2,§;. (265) studied rumen load as affected by level of intake and ration. Silage and companion hay were fed ad lib. and at a maintenance level. On ad lib. feeding, more hay than silage was consumed. Feeding hay resulted in more digesta and dry matter in the reticulo-rumen, which was in agreement with work by Thomas g§_§l. (251). Both authors concluded that rumen capacity was not limiting the intake of silage. Water was limited to a normal by Waldo §§_§;, (265) and no Specific comparison was made between "fill" just after eating and "fill" just before eating. Carr and Jacobson (52) studied the effect of adding 33 inert bulk (polyethylene cubes and rubber containers of water) to the rumen and removing rumen digesta on ad lib. intake. The addition of 2,6, and 10% metabolic size of inert bulk did not significantly decrease intake. A significant increase in consumption was noted when 10% of metabolic size as digesta was removed from the rumen. Removing 2.75 lb of dry matter/ 1000 lb body weight resulted in an increased consumption of 1.0 1b/1000 lb body weight. Veltman (263) studied the effect of stuffing hay into the rumen of two cows that were offered hay ad lib. Stuff- ing 10.3 lb of dry hay/day into the rumen of these cows via a fistula resulted in a decrease of 3.3 lb/day in voluntary intake of forage. Other feeds stuffed into the rumen caused varying degrees of decreased ad lib. consumption but there was always an increase in total dry matter consumption. Balch and Campling (12) concluded their review of "regulation of voluntary food intake in ruminants" by indicating that there is good reason to believe that the voluntary intake of roughages by ruminants is related to the amount of digesta in the reticulo-rumen at certain times. However, they also indicated a good deal more work is necessary to adequately ' integrate all factors concerned. Factors Affectipg_fieduction of Rumen Fil; If rumen fill or physical capcity was controlling for- 34 age consumption, then rate of passage, rate of physical breakdown, and digestibility would affect intake and in turn may be affected by intake. Rate of Passage Rate of passage could play a large role in the amount of forage consumed if rumen fill limits intake. Rate of passage or retention time of forage has been studied by using many different reference substances. Such inert sub- stances as rubber, tygon tubing, lucite, radioactive chromic oxide, iron oxide, chromic oxide, etc. have been used (47,50, 120,139,141,182,251). However, when such inert substances are used, one can question how the passage rate of inert par- ticles compared with that of the feed being studied. Thomas 2;.g;. (251) found that small lucite particles had a faster excretion curve than larger pieces of tygon tubing, and Campl- ing and Freer (47) reported that polystyrene particles passed through the G.I. tract faster than stained roughage particles. The most widely used technique to study rate of passage was introduced by Leukeit and Habeac (146). A small portion of straw or experimental feed was stained with a permanent stain. This technique was used by several workers in the 1930's and then not again until 1950. Since 1950 many wor- kers have used stained particles to study passage rate of forages (15.16.34.35,36,45,46,49,54,55,56,96,97,19l,196). 35 Rate of passage has been expressed in several differ- ent manners, one being the time between feeding the marker and its first or last appearance in the feces (29,158). The former is a measure of the maximum velocity that the material will pass through the gut. The last appearance of a marker is indistinct and of little value as a small amount of the marker tends to stay in the rumen. Excretion curves plott- ing time against percent of marker excreted have been used by Balch §£_§;, (15,16,17,96),Blaxter §£_al. (34,35), doors and Winter (182), Lambourne (1&1), Poijarvi (200), and Castle (54,55,56), to give a cumulative graph depicting rate of excretion. Data from different experiments expressed in terms of cumulative excretion curves are difficult and cum- bersome to compare. It is possible to compare different points on the curves, such as time when 5% or 80% of the to- tal marker is excreted or elapsed time from the 5 to the 80% point. However, this still doesn't give a good measure of the shape of the curve. Castle (5h,55,56) proposed the value "R" which is directly related to the area below and to the left of the passage curve. The "R" value is determined by adding together the excretion times from 5% to 95% by inter- vals of 10% and dividing the sum by 10. This gives a value for mean retention time of residues in the alimentary tract. This method has been employed by several workers (05,46,u9, 36 97,196) in the study of passage rate of digesta in ruminants. Ewing and Smith (89) expressed retention time by mak- ing use of water content ratios in feed, digesta, and feces. Paloheimo gt §;,(l56,l92,193,194) proposed using "the mean time of retention of a dry matter point of the food" concept. Mean time of retention in the rumen was determined by dividing daily dry matter content in the rumen by the dry matter intake. Thomas §§_§;, (251) and Waldo ggflgl. (265) used this concept of retention time in studying the relation between rumen con- tent and forage intake. This measurement must change with time after feeding, but should be comparative when observed under standard conditions. Rate of passage of digesta in ruminants fed only roughages is probably primarily affected by level of intake. Mitchell et al.(180) in 1928 studied rate of passage and sug- gested a relation with intake. Many workers have since reported that increased forage intake resulted in a faster passage rate or a decreased mean reticulo—rumen retention time of digesta (17,34,36,45,49,5h,55,56,96,97,157,l91,192, 194,251,265). Blaxter §§_§;, (35) fed three levels of dried grass to sheep and clearly showed an inverse relation bet- ween intake and rate of passage. Thomas (251) reported a curvilinear inverse relationship between dry matter consump- 11. (“9) (‘1 tion per cwt and rumen retention time. Campling g; 37 found similar results. With green chOp the above relationship appeared to be linear (251). These data clearly showed that increasing intake below ad lib. consumption increased rate of passage. Data were not available to clearly demonstrate whether ad lib. intake determined or was a result of passage rate. Makela (6) reported a correlation of -.7h between dry matter retention time and dry matter intake when forage made up the entire ration for dairy cows. Other workers (251) reported correlation coefficients between retention time and dry matter intake of -.77. Stallcup gt a;. (238) fed several lespedeza varities containing 33.27.20, 17 and 15% lignin to fistulated steers to study the effect of lignin content on rate of passage. By weighing and sampling rumen contents before feeding, 6 and 12 hours after feeding, these workers showed that as lignin content in the forage increased rate of digesta passage from the rumen decreased. The main factor reaponsible for physical breakdown of the consumed long forage to the size found in the abomasum must be due to chewing during eating and rumination. Freer gt_§l. (97) suggested the above relation when he found a dir- ect relation between eating plus rumination time per pound of forage and rate of digesta passage from the reticulo-rumen. However, at present very little is known about the action of 38 the omasum or the reticulum-omasal orifice as a filtering device for digests ready to be passed on from the rumen (13). Only well broken down material passes through the omasum. This was illustrated by the fact that only very short pieces of forage were found in the abomasum of ruminants. In general, more finely ground food passes through the digestive tract faster than the same food ground more coarsely or not ground. Balch (17) reported that ground hay residues when fed to a cow receiving a ration of long hay passed at a faster rate than residues of the long hay. Blaxer §£_§1, (35) fed dried grass in three forms(long, medium ground—pelleted, and fine ground-pelleted) to sheep. Each feed was fed at the rate of 1500, 1200 and 600 g per day. Rate of passage increased with the fineness of grind. Campl- ing g; 3;, (#5) fed ad lib. ground and long hay to cows. Mean retention time of stained hay on ad lib. feeding was slightly less for the ground hay. One cow had a faster pas- sage rate of the ground material while the other 3 showed little difference or faster passage for the long hay. When only 8.7 lb of either ground or long hay were fed, the mean retention time of ground hay was less (56 hours vs. 85 hours for the long hay). Mean retention time of dry matter in the reticulo-rumen was least for ground pelleted, intermediate for ground and longest for baled costal Bermuda grass When 39 fed to dairy heifers (191). In this trial, the difference in mean retention time may have been due to the differences in amount consumed and not to physical form. Daily consump- tion was highest for pelleted forage and lowest for ground forage. However, Rodrigue (222) reported that rate of passage was affected by degree of grinding and indicated all such experiments should state the fineness of grind. Campling and Freer (#7) studied the affect of size and specific gravity of inert particles on passage rate. At a Specific gravity of 1.20, mean retention time was dir- ectly related to size (h.8, h.0 and 3.2 mm in diameter of methyl methccrylate particles). King and Moore (139) repor- ted a curvilinear relation between rate of passage and specific gravity with maximum passage rate when the particle size was 20 to 30 x 10"3 cm3. The shortest mean time of retention through the gastro intestinal tract was found with particles having a specific gravity of 1.12 and the longest with particles having a specific gravity of 1.02. However, mean time of retention in the reticulo-rumen decreased as the Specific gravity increased from 1.02 to 1.21, while the reverse was true in the lower gut, where the mean time of retention increased as the specific gravity increased. The mean time of retention of the inert particle was less with a diet of dried grass than with a more mature hay. King and 40 Moore (139) found that particles with a specific gravity of 1.20 gave minimum mean retention time with a ration of hay and concentrate. Forage Digestibility For many years great emphasis has been placed on for- age digestibility as a measure of its nutritive value. It is well known that early out forage will be consumed in greater quantities than a more mature forage (60,102,126, 151,152,172,207,211,2lu,234,236,256,275). Reid §£.§1, (21h) reported a high correlation between maturity and digestibil- ity. He did not give the correlation between intake and digestibility but reported a trend of decreasing intake with lower digestibility and more maturity. Other workers (32,- 33,3U,35,69) have reported positive correlations between dry matter intake and percent digestibility of forages. The above relations were based on forages with a wide range in digestibilities (u5 to 75%). The wide range in digestibil- ity was obtained by using forages harvested at several stages of maturity. Thus the positive correlation between intake and digestibility was a consequence of both digesti- bility and maturity. Blaxter (37) stated that "the amount of feed taken, measured in terms of dry matter, increases with increasing concentration of the ration (net energy/kg dry matter)". The #1 reverse is true with most non-ruminant animals, as they will, within limits, eat more of a feed low in energy than of a feed with high nutrient density (38,39,138,162). Blaxter’s above statement may be true with certain forages in the case of ruminants. Conrad _t_§;, (63) determined voluntary intake of 82 different rations ranging in digestibility from 53 to 80%. Intake of rations (largely made up of roughages) between 53 and 67% digestible was directly related to diges- tibility. The differences in consumption could be accounted for by digestibility, indigestible residue, rate of passage and body weight. Intake of feeds decreased as digestibility increased from 66 to 80%. There was little tendency for consumption of forage to increase when digestibility in- creased above 70%. Intake was related to digestible energy and body weight to the .62 power, which was not significantly different from body weight to the .73 power. Blaxter g£_§l, (3h) reported that the consumption of poor quality hay was more related to body size than with hay of good quality (r= .8 vs. .5). This might indicate that rumen fill was more important in limiting intake of the poorer quality forage. Blaxter_gt a1. (35) suggested that highly digestible forages resulted in a faster rate of passage and higher ad lib. in— take than forages lower in digestibility. In a later exper- iment (3h) poor, medium, and good quality hay were fed ad lib. to mature sheep. Intake of the better quality forage uz was greater and resulted in faster passage rates. Campling §t_§l. (49) reported that passage rate of straw fed to cows was slower, when fed ad lib. or in restricted amounts, then passage rate of a good quality hay fed ad lib. or in res- tricted amounts. One wonders what affect the low protein in both the previous experiments had on rates of passage or degradation of forage dry matter. Freer and Campling (96) reported that ad lib. intake of dried grass was higher than that of hay and had a lower mean reticulo-rumen retention time. These experiments would suggest that for- ages of higher digestibility result in a faster rate of passage allowing for greater consumption. Forage Degradation Rate Forage degradation or breakdown rate could have a great deal of influence on level of intake assuming that for- age intake is regulated by rumen fill. Balch and Johnson (18) studied factors affecting rate of cotton thread break— down in the rumen and found breakdown to be faster in the ventral sac than in the dorsal sac. Cellulose breakdown was slower when ground hay rather than long hay was fed. A low dry matter content in the rumen favored rapid breakdown. Campling gg'gl. (M5) reported that feeding a ground forage diet reduced rate of cotton thread breakdown. Cotton thread was broken down six times faster when cows received hay as 43 compared to straw. Cotton thread digestion decreased slightly as intake increased from 10 1b/day to ad lib. Later work (96) showed that in animals receiving hay 25% of the cotton thread was digested in 22 hours, whereas in animals receiving only concentrate 25% of the cotton thread was not digested in 240 hours. Fiber and lignin content increases as forage matures (76,83,133,19o,207,223,235,237,2u2,2u3,257). husoff (223) cited others as showing that as lignin content increased there was a decrease in digestibility of other plant con- stituents. Dehority and Johnson (78) showed that as lignin content increased with maturation the in vitro cellulose di- gestion rate was decreased. After this same material was ball milled the initial incubation or fermentation time necessary to observe cellulose digestion by rumen microorganisms was reduced. Also the authors observed further digestion of the forage after ball milling a digested sample. The authors concluded that this was direct evidence for the "incapsulating" effect of lignin on other plant constituents. Workers at Ohio (77,12h,129,255) have suggested a difference in rate of in vitro cellulose digestion of grasses and legumes due to differences in chemical make up of legumes and grasses. Donefer g; g1. (82) found that the 12 hour in vitro cellulose digestion was closely related to intake. He 4h concluded that the early rate of digestion may, to a large extent, control intake. The evidence reported so far suggests that rumen fill, rate of passage, digestibility, and rate of forage breakdown are definitely related to intake. In many cases it is very difficult to separate cause from effect. Effect of Urea..Thyroxine._or Limited Water on Digestion and Intake. Urea added to low quality forage having a low crude protein content has been reported to increase intake (95,100, 113,183,185,276). Minson and Pigden (176) found urea added to poor quality forage decreased intake with little change in digestibility. Campling (220) administered urea via a fistula to cows receiving straw ad lib. The urea, infused to avoid any possible effect on straw palatability, markedly increased digestibility and intake. The rate of cotton thread breakdown in the rumen increased with added urea and mean retention time of hay in the reticulo-rumen decreased. In a later paper (97) these workers compared diets of hay, straw, and straw plus urea. They suggested that the amount of these forages eaten was dependent on the time necessary to physically and chemically break down the forages by chew- ing and microbial digestion respectively, to a size that could pass through the omasum. Thyroxine has been shown to increase milk production, food intake and metabolic rate. Balch and co-workers (16) 45 seizudied the effect of thyroxine on rate of passage and di- ggesstibility of a hay and concentrate ration fed Just below .Exlppetite. A definite increase in metabolic rate was found w 1th little difference in digestibility. However, crude fiber digestion was increased slightly though not signifi- czzantly. The initial appearance of stained particles was not aagffected by thyroxine treatment. During thyroxine treatment SSGZ and 5 to 80% excretion times were less than those found jzlrevious to treatment with some cow differences. The authors ssuggested that if rate of passage did not increase during ‘tihyroxine treatment for an individual cow, then the fiber 'éiigestion increased. Water intake rose during thyroxine treatment. In a later experiment Balch gt 3;. (15) studied the effect” of limiting water intake on digestibility. Any change ‘wossibly due to increased flow of saliva. Passage rate 8 howed a slight trend towards slower excretion. They ESuggested that rate of passage might slow down as the animals {become accustomed to an all forage ration. Rate of breakdown <>f cotton thread in the dorsal sac of the rumen decreased dur- #6 111g the second week of water restriction; however digestion treate increased throughout the experiment in the ventral sac. Palatabilit] The term palatability (agreeable to the palate or LEDJLeasant to the taste) has been used with many meanings. Blaxter g}; _a_l_. (31+) and Campling _e__t_ _a_1_. (49) have indicated that voluntary intake of forage can be explained by physical regulation of appetite without using the concept of palata- bility. Blaxter _e_t gl. (31+) feels the term palatability should not be used in reference to animal feeds. Thomas (at.§;, (252) added several flavor compounds to silage to in- <3rease intake and concluded that reduced intake of silage in (somparison to companion hay was due to metabolic and products Eind not palatability. Experiments have shown that poultry have a sense of tzaste (136). The birds were able to detect and reject very 13.0w levels of certain flavors. Man's and bird's concept of ‘tzaste differed. Baby pig rations containing saccharin were consumed at a rate 3.5 times the ration without saccharin (1+). When 5 levels of saccharin were offered the results Vraried. Miller 23,3l, (175) showed in cafeteria type experi- tnents that anise oil added to the calf ration decreased intake. Even the type of anise oil used made a difference in 47 tslle amount of reduction in feed intake. Stubies and Kare ( 2341) concluded that cows have a sense of taste that was .rrealatively acute, but somewhat different from man's. Ivins (127) reviewed the "palatability of herbage" zaqrid concluded that cattle showed a definite preference for E3<>me pasture plants over others. Only limited data are avail- :sxlale as to the importance of these differences on animal pro- <3Jaotion when no choice is offered. Leigh (144) studied the relative palatability of ESeveral varieties of weeping love grass. Twenty varieties ‘Vvere planted in plots 20 x 40 ft which were further divided into 3 fertilizer treatments. Cattle were accustomed to the .IDlot area, then allowed to graze. Time spent grazing and Eipecific area grazed was recorded. There was a great diffe- lI‘ence in the acceptability of the different varieties. These Il‘esults indicated that the variety presently used in most ESomth Africa forage research was the least palatable. The 31.evel of fiber in these varieties was not important in influencing palatability. Barnes gt,§;. (19,20,186), by using cafeteria type égrazing trials with sheep, selected two unpalatable and two IIDaIatable canary grass clones to study effects on in vivo fiigestibility and ad lib. intake. When sheep received the :forages ad lib. there was a positive relation with diges- ‘tibility, but not when intake was restricted. There seemed #8 t:<) be a positive relation between cafeteria palatability :zraatings and NVI or DM intake, which was more pronounced in ‘t;11e aftermath than in the first cuttings. Hammes g£_§;. (110) studied the palatability of coastal ‘tnearmudagrass and alfalfa hays. Steers were allowed either Eailfalfa or bermudagrass for three days and then were reversed. Aggfter the second period all the animals were allowed a choice ‘taetween the two hays. Alfalfa was consumed at the rate of 22.2.lb dry matter/cwt while only 1.55 lb of bermudagrass was consumed when no choice was allowed. When a choice was eallowed, 2.2 lb of alfalfa and 0.4 lb of bermudagrass were <3onsumed. At this time there is not sufficient data to (eliminate the term palatability as a regulator of feed intake, Itmor is there sufficient data to indicate its importance in 1:erms of animal production. Lignin as a Marker Inert or indigestible markers may be used to determine icahanges along the gastrointestinal tract of ruminants by the irratio technique. Hale (106,108,109) and Balch (In) suggested tzhe use of lignin ratio to study chemical changes in the Ireticulo-rumen. The assumption was made that lignin is non- otentials for animal performance, (3) to determine the (effectiveness of rabbits in estimating large animal per- :formance and nutritive value as determined by large animals, (A) to study the relationships between forage intake,rumen :fill and rumen retention time of dry matter, fiber and lignin. Forage; - 1961_Crop Three cuttings of pure stands of alfalfa (Vernal), t>irdsfoot trefoil (Viking), brome grass (Canadian) and reed caanarygrass (Common) were harvested in 1961. Only one cutt- fiLng of timothy (Commercial) was available due to the slow IPecovery of timothy. Forage cutting dates were June 17, .éaugust 3 and September 8 for first, second and third cuttings, ixrespectively. All cuttings were from the same field and cut eat the same time with the exception of alfalfa. Alfalfa :first (Alf.I), second (Alf.2) and third (Alf.III) cutting twere from the same field; however, Alfalfa-2 was harvested July 12 rather than August 3. Thus alfalfa III had a longer 50 51 ggzwowing period than the other third-cutting forages. Alfalfa II was cut on August 3 from a different field than the above aallgfalfas and the first cutting had been removed about June 11.17 . Thus, although the alfalfa II was from a different field 1: hen the other alfalfas, it had a regrowth period similar to 'tztiat of the other second cut forages. The grass forages were grown on Houghton muck soil ‘vvlnile the legumes were grown on upland soil. The grasses received 100 1b nitrogen per acre on April 15. Forage yields ( Table 2) were determined for the 1961 crop by the M.S.U. Crop Science Department. These data were not available for tzlie 1962 crop. TABLE 2. Dry Matter Yields of Pure Stand Forages - 1961 CrOp. Cutting, ____ Forage lst 2nd;, 3rd Total' tons/acre IBirdBfoot trefoil 1.60 1.43 1.17 “.20 AAlfalfa 1.67 1.72 0.7h n.13 IBrome grass 1.42 0.91 0.85 3.18 Iieed canary grass 1.66 1.38 1.15 “.19 The forages were harvested in a normal manner; par- t lally field cured, baled and placed on a heated barn dryer ‘t3<3 prevent weather damage. At the time of feeding the for- a~ges were chOpped into about 1 inch lengths to facilitate Weighing and prevent wastage when fed to sheep and heifers. Ii small portion of each forage was ground in a Letz chopper 52 salad pelleted into 3/8 inch pellets for feeding to rabbits. Forages - 1962 Crop The 1962 forages were handled in a manner similar to ‘tzlnat of the 1961 forages. However, only two cuttings of each salpecies were obtained due to dry weather. First cutting (EiZLfalfa I, canary grass I, brome I, timothy I and trefoil 1 'Vvesre harvested May 28, May 31, May 31, June 4 and June u, Ireespectively. Trefoil I received a little rain soon after zapt was cut. Second cutting alfalfa II, brome II, canary girass II and trefoil II were harvested July 10, July 12, gJWle 12 and July 16, respectively. Second cutting brome eaznd canary grass received light rain the evening after outt- :LJng. Standard methods, largely those of A.O.A.C. (11) with Stilecessary modifications in accordance with equipment avail- aafble, were used to determine forage protein (N x 6.25),. 1 Eadmmonium, ether extract (E.E.), ash, phosphorus and sulfur. IF‘iber and lignin content of hay and feces were determined by Van Soest's acid-detergent method (262). These values were LAsed to determine fiber and lignin digestion coefficients :f‘or all forages. Gross energy of forages, orts and feces \ These analyses were carried out by Dr. E.J. Benne, MSU, Biochemistry Department. 53 DVGBPB determined by a Parr bomb calorimeter apparatus. Sol- Laljle carbohydrate content of the solute from Van Soest's 1Fd1ber determinations were determined by the phenol-sulfuric 15L<3id method (Analytical Chemistry 28:350, 1956). Sub-samples <>:f the 1961 forages were also sent to Van Soest's laboratory 1F<3r analysis of lignin, fiber and cell wall constituents. Sheep Trials - 1961 Crop Twelve wethers weighing approximately 70 1b were used inn.three 4 x # latin squares to study intake, body weight gggain and digestibility of the forages. To obtain data on éailfalfa-Z and timothy, two wethers were alternated back and iflorth on the two forages. The three latin squares contained 1Scnu'different forage species of the same cutting and each JE>eriod extended for 25 days. A weighed amount of forage Was fed twice daily and refusals were weighed daily in the Gazarly afternoon to allow a period of about three hours when no feed was in the mangers. A scale graduated in ounces was used to weigh all feed and orts. Five grams of a 1:1 mixture of trace mineralized salt Eacnd dicalcium phosphate was fed daily. 1 ibitum. Water was offered ad At the beginning of each feeding period the for- 8186 was fed at the rate of 2 lb/cwt. and then adjusted rapidly tlhe first few days. The portion offered was increased to 3L5% in excess of consumption. The amount offered was not 54 decreased unless weight back was in excess of 15% for 2 or 3 days. The wethers were fed in individual pens for the first 12 days of the eXperiment then placed in conventional digestion stalls through the 20th day, after which they were returned to individual pens. Originally it was planned to keep the wethers in the collection stalls throughout the experiment; however, they became very weak in the hind legs from standing on a wire mesh support. Average daily volun- tary dry matter intake was determined using consumption data for the last 19 days of each period. Dry matter was deter- mined weekly on each forage. All dry matter samples unless otherwise stated were dried at 80°C for approximately #8 hours in a forced air oven. The body weight changes were determined from day 7 through day 25 based on the average of consecutive weights over a 3 day period. All weighings were made at 4:00 p.m. §§§ep Trials - 1962 Crop Feeding and collection trials using forages harvested in 1962 were similar to those of the 1961 crOp. However, it was thought that a slightly longer feeding period was desir- able and consequently each period was prolonged to 28 days. Timothy I was fed alternately to 2 sheep. Each period the wether not receiving timothy was fed a good mixed hay. Feed consumption was determined daily but that consumed from day 55 8 through 21 was used to determine daily intake average. This procedure was a more precise estimate of maximum intake than in the previous year's data which contained intake data collected during the slight drOp in consumption found near the end of the collection period. Body weight changes were determined from day 6 through 28 based on the average of 3 consecutive daily weighings. Sheep Digestion Trials Digestion trials were conducted in collection crates allowing for separation of urine and feces. The wethers receiving the 1961 forages were placed in the collection crates on the 12th day of each period with actual feces collection from day In through 20. Feces were collected from day 20 through 26 from sheep receiving the 1962 forages. Total feces were collected daily and placed in a container kept at 2°C. At the end of each 7 day collection period the feces from each sheep were thoroughly mixed. Approximately 10% were dried at 80°C and ground for chemical analysis. At the same time another sample was obtained and dried at 40°C. for fiber and lignin determinations. During the collection trial a daily sample (approximately one hand full) of each hay was obtained. The 7 day composite sample was thoroughly mixed on a table and one-half dried for chemical analysis. The rest of the sample was saved for use as an in vitro fer- 56 mentation substrate. All orts during each collection period were composited into a covered can. At the completion of each digestion trial these orts were mixed and sampled. The sample was dried at 80°C to determine % dry matter. Digestible dry matter (dig.DM), digestible organic matter, digestible energy and estimated TDN were determined for all forages. Digestion coefficients were calculated by dividing retained nutrients by nutrients consumed which were based on total intake and fecal excretion during the 7 day collection period. TDN was estimated by the method of G.P. Lofgreen (150) as indicated in the following formula: Estimated TDN = M (.01 + .000125 E): % dig. organic matter; where M = % organic matter and E = % ether extract. Dry matter nutritive value index (DM NVI)was determined by the following formula: DM NVI = 100 ' Observed D“ intake x % digestible DM. 80 (wt.kg' Crampton's 23.31. (67) formula for NVI was similar except % digestible energy was used in place of % digestible dry matter. In vitro NVI was determined from the following formula: % 6 hr. DM disappearance . % 36 hr. DM In vitro NVI = Qiaassaazaase of substrate 100 In vitro dry matter disappearance is discussed on pages 59 "' 63o 57 Rabpgt Trial - 1261 Crop Growing Dutch belted rabbits weighing 600-1000 g were fed the fourteen 1961 forages in six replications for h weeks. The rabbits had been weaned and were receiving commercial rabbit pellets at the start of the experiment. Fourteen rab- bits were started simultaneously with one rabbit on each hay. The average initial weights for all groups were approx- imately the same. The rabbits were housed in stainless steel cages with wire mesh floors in a large temperature controlled room. Feed and water containers were hung on the door of each cage. A U-shaped strip of metal with bottom and sides was attached to the floor under each feed tray to help prevent wastage. Bedding was not used in the front half of the excreta tray to allow daily removal of wasted feed. The pelleted forage under investigation was fed ad lib. as the sole ration except that salt blocks were avail- able at all times. Feed intake was determined weekly for the last three weeks of the trial. The pelleted forage was sampled and % dry matter determined. A seven day total collection of excreta was made during the 3rd or hth week of the trial to determine dry matter digestion coefficients. The feces were dried at 80°C for #8 hours and then weighed to determine total dry matter voided during the 7 day collection. 58 Weight gain was determined for the last three weeks of the trial from weighings made on 3 consecutive days each week. Dairy Heifer Trial - 1961 Crop The objective of this trial was to obtain data that could be used to compare reSponses when pure stand forages were fed. However, the amount of hay was limiting and result- ed in a short trial with a small number of animals (3 to 4 per group). Two heifers in the brome I group and one in the reed II group deveIOped coccidiosis and were removed from the experiment, which left two animals per group. Dairy heifers weighing approximately 350-800 1b were fed ad lib. the chopped experimental forages twice daily (10% excess). Water was available at all times. Fifty grams of a 1:1 mixture of trace mineralized salt and dicalcium phosphate were fed daily. Orts were weighed back and record- ed daily and dry matter was determined weekly on hay and ort samples. Digestion coefficients as determined by sheep were applied to the dry matter intake of the dairy heifers to determine dig. dry matter intake as several workers have shown that sheep and cattle give similar digestion coefficients for forages (3,245). The experimental hay was fed for 10 days previous to the start of the eXperiment. All heifers were weighed for three consecutive days at the beginning of the experiment and thereafter every two weeks 59 until the supply of that particular hay was exhausted. In litre Fermentation - 1961 Forages Strained rumen fluid was used to digest forage sub- strates. Digestion was measured by the amount of the added substrate that would pass through a sintered glass filtering crucible after a designated period of fermentation. This method was similar to that of Bowden and Church (41,42,58) and was selected because of simplicity and because the method measured dry matter disappearance. Oven dried com- posite samples taken from 4 samples of each forage collected during the digestion trials were ground through a 1 mm mesh Wiley mill screen, thoroughly mixed, and stored at 35°F. Rumen inoculum was obtained from a fistulated Hol- stein cow maintained on 26 lb of timothy-brome hay contain- ing 5-10% alfalfa. Water was available at all times and 50 g of a 1:1 mixture of salt and dicalcium phOSphate was fed daily. On days of inoculum collection, the cow was fed at 7:00 a.m. Feed and water were removed at 8:00 a.m. and the rumen juice was collected at 9:00 a.m. Rumen ingesta were obtained by hand from an area below the fistula and the juice eXpelled by squeezing. The juice was then strained through four layers of cheesecloth into a prewarmed thermos jug and transported to the labora- tory. Carbon dioxide was bubbled through the rumen juice for 60 two minutes. The buffer solution for the in vitro fermentations was made up as follows. A 0.1M pH? phOSphate buffer was made from 2.04 g KHZPOu plus 4.36 g NaZHP04 and made to 500 ml with water. A urea stock solution was made from 8.00 g of urea diluted to 100 ml with water. A sodium carbonate stock solution was made from 18.4 g (N82003°H20) and diluted to 100 ml with water. Two ml of the sodium carbonate stock solution and 2.5 m1 of the stock urea solution were added to 100 ml of buffer. The fermentation mixture contained about .05% added urea which was the level suggested by Salsbury (228). Just before using, the buffer solution with added urea and sodium carbonate was warmed and C02 bubbled through it until a pH of 6.8 was reached. An all glass fermentation system was used consisting of a 125 m1 erlenmeyer flask fitted with a one-holed rubber stOpper and bunsen valve made from rubber tubing. One gram (3 .003 g) of forage substrate was added to each flask. Fermentations were carried out in a large temperature controlled circulating hot water bath maintained at 39°C. At 8:30 to 9:00 a.m. 20 ml of buffer solution was added to each flask containing the substrate. At 9:30 a.m. 60 ml of rumen inoculum was added to each flask. Similar amounts of rumen inoculum were added to four flasks without added sub- strate in order to determine residual non-filterable dry mat- 61 ter originating from the inoculum. The flask was then flushed with CO stOppered, and 2: incubated in the hot water bath for 3,6,12,18,24,36 or 48 hours. Other work suggested that continued bubbling of the fermentation mixture with C02 was not necessary (337). At the end of the designated fermentation interval, one drOp of 20% thymol solution was added to the mixture and the flask placed in a freezer (-10°C). Each fermentation trial (fer- mentations started the same day) consisted of 7 or 8 different forages all fermented for 7 different time intervals. Also with each fermentation trial, duplicate dry matter disappearance determinations were made on a standard alfalfa hay. IngVitro Fermentation - 1962 Forages The fermentation procedure was similar to that used for the 1961 forages with some slight changes. The donor cow received good quality alfalfa hay (5-10% mixed grass) throughout the experiment. After arriving at the laboratory, the rumen fluid was allowed to stand in large erlenmeyer flasks at 39°C for one half hour. This allowed the particu- late matter to rise. The bottom, or more fluid portion was then siphoned off and bubbled with 002 for two minutes. hemoving the particulate matter reduced the variation between replicates to a level similar to that obtained by other invest- igators (25,26,29). Non-filterable dry matter added to the 62 fermentation mixture by 24 m1 of rumen fluid for each trial conducted on the 1961 and 1962 forages is shown in appendix Table XXVI. The residual non-filterable dry matter contri- buted by settled rumen fluid was & that contributed by non- settled fluid. Dry matter disappearance was determined by filtering the fermented material through a tared coarse sintered glass filter (Corning Cat. #329400). Frozen fermented samples were thawed in warm water (4000) and quantitatively washed into filtering crucibles. However, when vacuum was applied, the sintered glass filters became plugged and very slow filtering occurred. To alleviate this, a solka flock paste (solka flock and H20 mixed in a waring blender for 5 min) was placed in each filtering crucible to make a %" filtering plug or layer. Water was removed by applying a slight vacuum. The filtering layer was then rewashed with 50 m1 of distilled H20. The filtering crucible with its filtering pad was then dried in a forced air oven at 80°C for 36 hours, placed in a desicator for 30 min and then weighed. The fermented sample was then washed into the tared crucible with distilled water and vacuum applied to remove the water. The non- filterable material was then rinsed by drawing through 50 m1 of distilled water. The crucible was then dried, placed in a desiccator and re-weighed as previously described. The average non-filterable residual dry matter contributed by 63 the rumen inoculum was subtracted from the total non-filterable dry matter. This allowed one to determine the portion of the added substrate that did not disappear during the fermentation process. (Total non—filterable DM - residual non-filterable rumen inoculum DM = "undigested" portion of substrate). The substrate “digested" or substrate disappearance was calcu- 1ated by the following formula: substrate added-non-filterable or g DM disappearance = "undigested"ppprtion of substrate x 100 substrate added By the nature of the above procedure some of the dry matter disappearance was due to loss of water-soluble portions of added substrate and part by microbial digestion. There- fore dry matter disappearance of each forage substrate was determined by incubating with only buffer solution for 3 hours. Extra buffer was added in place of the rumen inoculum. Dry matter disappearance due to rumen inoculum was determined by subtracting three hour buffer soluble dry matter from total dry matter disappearance at the different fermentation inter- vals. Slaughter Trials - 1961 C302 Second cut trefoil, alfalfa, brome grass and canary grass were fed to 3 wethers for 14 days. These particular forages had the maximum intake range of all the 1961 forages and yet had similar dry matter digestion coefficients. Intake 64 data for the slaughter trial were based on average consump- tion for days 11 through 13. The wethers were slaughtered on the 14th day 6 hours after feeding or halfway between feedings. Feed and water was available until about 2 hours before killing. The wethers were killed, their hides quickly removed and the gastro-intestinal (G.I.) tract removed. The G.I. tract was then tied off between the reticulum and omasum, small intestine and large intestine and at the base of the cecum. The pH of fresh rumen contents was obtained immed- iately. Fiber and lignin contents of digesta in the rumen and lower large intestine were determined on dried (40°C) portions by the Van Soest acid-detergent method (262). _laughter Trial - 962 CroQ The 1962 cr0p slaughter trials were carried out in a manner similar to that for the 1961 forages except for a few changes. First cut alfalfa, trefoil, timothy and canary grass were each fed individually to 4 sheep for 14 days. In- take was determined for the last three days of the period. Feed was offered ad lib. at 12 hour intervals. Orts from the last feeding were removed one hour after feeding. Two sheep from each forage group were killed six hours after feeding while the other two were killed 12 hours after feeding 65 or just prior to the next feeding. Available facilities made it necessary to slaughter the sheep on two consecutive days. The gastro-intestinal tract sections were tied off as in the previous trial with the exception that the large intes- tine was divided at a point where pelleted feces in the tract were obvious. Thus this organ was divided into upper large intestine (excluding cecum) and lower large intestine. Sam- ples from the lower large intestine were considered to be similar to feces. From each rumen sample 20 grams of digesta were placed in a large test tube with 20 ml of .6 N H280“ and frozen until analyzed for volatile fatty acids (CZ-Ch). At the time of analysis the samples were thawed and centrifuged at 2,000 rpm for 10 minutes. The supernatant was poured off into small sample bottles. To keep the recorded peaks on the recording chart, the samples were diluted 2 to 4 times with distilled water acidified to pH 2 with H230“. Volatile fatty acids in the rumen contents were deter- mined by using an aerograph model A-600-D “Hi'Fi" gas chroma- graph with an hydrogen flame ionization detector coupled with a Sargent SRL recorder. The absorbing column was five feet long by 1/8" in diameter and contained 15% versamid 900, 5% isophthalic acid on 60/80 chromosorb w. A 135°C chamber 0 temperature was maintained with the injection port at 190 C. 66 Nitrogen was used as a carrier gas. Five tenths ml of the final sample solutions was injected into the apparatus. The amounts of acetic, prOpionic and butyric acids were calculated by measuring the recorded peak heights and comparing these to a standard curve. The standard curve was made by using known dilutions of barium acetate, sodium propionate and sodium butyrate to give peak heights in the range of those found in the samples being tested. The standard acetate, prOpionate and butyrate solu- tions were mixed and 0.5 ul injected. Peak height rather than area was used to determine concentrations because of sharp and very narrow peak widths. Measuring the peak width would probably induce more error rather than reduce error under these circumstances. Rumen retention time was determined by a method simi- 1ar to that of Paloheimo (194) as shown in the following for- mula: DM contents in the rumen/cwt Rumen retention time of DM = Daily DM intake/cwt Rumen retention time of fiber and lignin was determined in a similar manner by substituting fiber or lignin for dry mat- ter (DM). Dry matter and fiber disappearance from the rumen and large intestine were determined by using the lignin ratio technique as prOposed by Hale gg al., (105}. . The formula 67 for determining "digestion" or disappearance from the rumen was as follows: J _ §_lignin in hay. anutrient in rumen % digestion ‘ 10° ' % nutrient in hay x zfilignin in rumen x 100 There was assumed to be no "digestion" of lignin in the rumen. Indigestible lignin in the hay was determined from the total collection trials. RESULTS Forages Protein content of the experimental forages ranged from 14% for timothy to 32% for Brome III (Table 3). Although the protein content of brome grass was high, other workers (127) have reported up to 39% crude protein in young brome grass. Ammonia nitrogen was determined to ascertain how much of the crude protein (N x 6.25) was ammonia nitrogen. The maximum ammonia nitrogen found in the forages harvested in 1961 (Table 3) was equivalent to about a percent unit of crude protein. Fiber content of the forages varied from 27 to 40% with grasses containing slightly less fiber than the legumes when considering forages of the same year and cutt- ing. Lignin content of the forages varied from 2.8 to 9.9%. Legumes in some cases contained 2 and 3 times as much lignin as did the grasses. Lignin analyses between our laboratory and Van Soest's were in reasonable agreement. Van Soest found that some of the isolated lignin from the forages con- tained nitrogen which he termed artifact nitrogen (Table 4). When forages are heated over 40°C the lignin fraction as measured by this method contains protein (N~6.25). Heat- ing the sample apparently may cause protein to bond with the lignin and cause an "elevated" lignin content. This arti- fact nitrOgen can be compensated for by a correction factor (153). These forage samples were not oven dried. 68 MW ooscfiucoo 35.: Ne.e .0: .me am.: 00.: a.mm o.em H eHe cc.e mn.e .3: .am me.m Na.m a.mm e.em H coca No.3 He.e .nm .em ma.m NH.: m.om e.Hm H oeoem “2.: m:.: .Hm .em e~.c p:.a «.mm o.cm H aHa mn.e mm.e .Hm .om ms.w mm.m a.mm n.5m H one ‘m\Hcmia one oHnaHom maaamaa maobHa mm. He. HH.OH mm. p.mm we. HHH econ me. am. om.m ma.e H.mm no. HHH pecan em. on. em.m mm.H a.mH no. HHH eHa mm. on. em.OH mp.m H.mm no. HHH one me. an. mm. em. mo.a we.c mm.m mH. N.HN H.om mo. HH coca Hm. mm. mm. mm. mm.m om.a sm.: mo.e m.mm c.3m 0H. HH oaoam u on. u mm. u m:.m u em.m . N.om me. m cHa mm. mm. mm. mm. as.“ ms.a mo.m ma.H c.0m c.5H no. HH cHa cm. mm. Hm. Hm. mm.m Hm.m mm.m mm.m m.aH m.aH no. HH ocH Hm. om. em. mm. ao.n mm.e be.m am.m a.mH N.eH Ho. H aHH es. en. Hm. Hm. em.a ec.m NH.m mm.m N.HN a.mm :0. H comm mm. em. on. Hm. mc.m oa.m mo.m mH.m H.3N H.N~ we. H oeocm Hm. mm. Hm. we. em.m em.e Ne.m am.H H.mH a.mH no. H cHa ow. om. 5H. Hm. mm.c mo.c mm.m mm.m H.mH m.bH no. H one NmmH HemH mmmH HmmH NmmH HmmH «mam . HmmH mmmH HwaH HmmH Hamasm msaosgmosm Sad m m HaHopoam +dmz owmaom mHmmm Hopumz ago so commoaawm w .aoao NomH can HemH snowmaom HmHaosHaoawm Ho mammama< HmeHaonu .m mqm mo cospoa an :HawHH cam amnHm HammaouopIpHomm mm.e a aowcacaa HeceHoHaH 00.: .Hm om.m m.mm HHH comm mw.: .mm mm.w 0.5m HHH macaw 53.: .mm Hd.w 3.0: HHH HHm on.: .:N md.u m.mN HHH mp9 Hm.z Hm.d .md .03 wm.m Hm.a m.mm H.Nm HH comm Ha.e mo.n .mm .mm mm.m no.5 m.mm m.mm HH oeocm I No.3 I .mm I mm.w I H.om m HH< HH. Hm.d .mm .wm mo.m mm.w a.mm a.mm HH MH< mm.: mm.: .Hm .mm ow.m q>.a m.om o.Hm H the mm H Hm H mm H Hm H mm,H Hw H mm H HwMH w\Hmo+x oxo oHnsHom NsHamHH NaonHm mHmmm coups: mag so commoamwm a; ommaom QMDZHBZOO Mimflmde 71 TABLE 4. Fiber and Lignin Content of 1961 Forages As Determined by Van Soest. Cell Acid Acid Deterg. Wall Deterg. Insol. Corrected* Sample Constit4¥ Fiber Lignin N x 6425 Lignin % p.m. % p.m. % p.m. z p.m. % p.m. Alf I 47.2 36.5 7.06 Alf II 49.8 37.9 8.24 Alf 2 42.2 31.3 5.74 Alf III 59.1 41.1 8.18 Tre I 49.0* 38.5* 9.53 1.52 9.31 Tre II 44.0* 31.4* 9.35 2.03 8.18 Tre III 36.9* 29.3* 8.05 1.77 7.07 Brome I 63.9 31.9 3.57 Brome II 59.9* 29.5* 7.36 2.79 4.41 Brome III 53.8* 24.5* 4.97 2.31 2.36 Read I 58.7 27.8 2.38 Reed II 67.6 32.4 3.67 Reed III 59.8 28.1 2.88 Tim.I 62.4 34.1 3.90 * Corrected for artifact lignin. Possibly the nitrogen contamination in the lignin could have occurred because of heating in the bales during curing. Cell wall constituents which includes lignin, holocel- lulose and cell wall proteins as determined by Van Soest (Table 4) were compared with intake and 5 dry matter digest- ion of the experimental forages for different animal Species. Cell wall constituents had little effect on sheep dry matter digestion coefficients but were negatively related to dry matter intake by sheep and heifers (r = -.70** and -.66* reSpectively, Table 5). Dry matter intake by rabbits was not significantly (P’>.05) related to cell wall constituents. However, rabbit digestion coefficients were negatively re— lated to forage cell wall constituents (r = -.74**). The above relations might indicate the inability of the rabbits' digestive system to degrade cell wall constituents of for- ages. However, cell wall constituents, though broken down by ruminants resulted in reduced intake. Chemical analysis and intake were used to calculate in- take of the various nutrients expressed as intake per 100 lb. live body weight (cwt). Sulfur and protein intake were adequate based on N.H.C. requirements (201). The assumption appear warranted that sheep performance on the different forages was limited by the level of energy consumed. Lignin and fiber content have been reported to adver- sely affect intake of forages. Fiber content of forages used TABLE 5. Simple Correlation Coefficients Between Digestibility and Intake of Forage Dry -Natter by Animals and Forage Content of 73 Fiber, Lignin and Cell Wall Constituents. NO. Forages r _g_ 1. Sheep % digestible DM vs.% fiber in * grasses 12 €;58‘_ 2. Sheep % digestible Dh vs. % fiber in leg- ** umes 11g -.79 3. Sheep 5 digestible DN vs.% fiber in all ,, __ foragps 23 -.66 u. Sheep % digestible DM vs.% lignin in , grasses _;2 -.65 5. Sheep % digestible DM vs.% lignin in legpmes 11 ~45} 6. Sheep % digestible DM vs.% lignin in all * forages 23‘ -.50 7. Sheep % digestible DM vs.cell wall con- stituent .gly :420 8. Rabbit % digestible DM vs. cell wall con- ** . stituent ,l3 1,?“ 9. Sheep DM intake/cwt vs.% fiber in all for- ages 23 .32_ 10. Sheep DM intake/cwt vs.% lignin in all ** forages 23_ -28 11. Sheep intake vs- cell wall constituent 23 -.20** 12I Heifer intake vs. cell wall congtituent l} -.66* 13. Rabbit intake vs. cell wall constituent 14 p.09 1h. Sheep digestible DM intake vs.% lignin ** in all forages 23 ‘59 continued 7b TABLEgj CONTINUED No. Forages r 15. Sheep di estible DH intake vs.% lignin * .(lggl forages) 14 .61 16. Sheep digestible DM intake vs.% lignin as determined by Van Soest (1961 forages) 1h .61* 4. Significant P<.05 ** Significant P (.01 in these experiments did not appear to be a decisive factor in regulating intake. The correlation coefficient between dry matter intake and % fiber was low but positive (r = +.37). A large positive correlation was found between lignin content and dry matter intake (r = +.78). Digestible dry matter intake was also positively correlated with lignin content of the experimental forages (r = +.59). As the fiber content of the forages increased the digestibility of the forages decreased (Table 5 - lines 1 through 3). To a lesser extent, digestibility of the forages decreased as the lignin content increased (Table 5 - lines 4 to 6). Sheep_Performance Various measurements of animal performance for the dif- ferent forages and cuttings in 1961, 1962 and combined data were determined and tabulated (Tables 6,7,8- Appendix Tables II through XI). TABLE 6. Several Criteria Used to Evalua Experimental Pure Stand Forages 2 (Sheep 1961 CrOp). Eezthe 75 DM DIE.DM Body F intake/ DM intake/ DW weight orage cwt dig. cwt EVI ain lb/day % ilp/day_ lb7da1 Alf I 3.00A8a 60.0Bb 1.80AB 55.8 .19 Tre I 3.28Aa 61.5Bb 2.01A 62.3 .27 Brome I 2.618b 61.9A8b 1.628 49.7 .12 Reed I 2.5le 65.1Aa 1.638 50.8 .16 Tim,I 3 2.43_ 63.8 1.55 u9.o _ila Alf II 3.20A8 55.8ab 1.78A8b 54.7A8b .21A8 Tre II 3.63A 60.0a 2.20Aa 66.7Aa .34A Brome II 2.618C 55.0b 1.43800 44.58C0 .028 Reed I 2.26C 55.0ab 1.25C0 38.7Cc .088 Alf 2 :5 2.27 65.1 llJSl 56.7 .22_, Tre III 2.95 64.1Ab 1.83 64.4 .30 Alf 1114 2.71 56.6Bc 1.53 47.1 .03 Brome III 2.54 65.7Ab 1.65 50.7 .19 Reed III 2.40 68.688 1.63 59- _420 Average lst cut 2.85 62.2A 1.76 54.6 .18 2nd cut 2.92 56.6B 1.67 51.2 .11 3rd cut 2.62 63.0A 1.66 53.1 .18 Alf 2.97b 57.580 1.7le 52.5 .13 Tre 3.25a 61.9Aab 2.01Aa 64.5 .28 Brome 2.590 60.6Ab 1.578b0 48.3 .11 Reed 2.380 63.1Aa 1.5080 46.6 .09 1 of 4 sheep. The values given for each cutting represents an average 2Values with like superscripts represents a homogenous group (large superscript P<(.01 and small superscript P (.05) 3Not included in the statistical analysis. “The second cutting was removed from this field 7/12 rather than 8/3. 5Harvested 7/12 from the same field as lst and 3rd cutting used in this study. 76 TABLE 7. Several Criteria Used to Evaluate the Experimental Pure Stand Forages (Sheep 1962 Crop) DM Dig.DM Body intake/ DM intake/ DM weight Forage cwt dig. cwt NVI -ain leday % lb7day ledaE Alf I 3.52Aa 65.3 2.30Aa 68.7Aa .28 Tre I 3.20Ab 61.7 1.98A8b 59.6A8b .17 Brome I 2.7080 66.8 1.8080b 53.480 .19 Reed 2.248d 65.0 1.4500 43.580 .07 Tim.I 2.66 62.2 1.65 50.3 .Olh‘ Alf II 3.58A 60.88 2.18Aa 65.5A .17 Tre II 3.34A 62.5A8b 2.09Aa 61.9A8a .18 Brome II 2.568 66.1Aa 1.69A8b 50.48b .11 Read II 2.378 61.18 1.458 43.48b .12 Average lst cut ' 2.91 64.7a 1.88 56.3 .18 2nd out 2.9? 62.6b 1.85 55.3 .15 Alf 3.56Aa 63.18 2.24A 67.1A .23 Tre 3.27Ab 62.18 2.03A8a 60.8A8a .17 Brome 2.6380 66.4A 1.758b 51.980b .15 Reed 2.3le 63.18 1.330 43.400 .09 1. Not included in statistical analysis. TABLE 8. Several Criteria Used to Evalute the Experimental Pure Stand Forages (Sheep 1961 and 1962 Crop Combined) 77 Dry Dry matter matter Digestible Body intake/ digesti- dry matter DM weight Forage cwt bility intake/cwt NVI gain glb7day _% lblday. lblday Alf I 3.260 62.6 2.05 62.2 .24 Tre I 3.24A 61.6 2.00 61.0 .22 Brome I 2.668 64.4 1.71 51.6 .16 Reed I 2.388 65.0 1.54 47.2 .12 Tim.11 2.54 63.0 1.60 49.6 .07 Alf II 3.39A 58.3 1.98A 60.1A .19ab Tre II 3.48A 61.2 2.14A 64.3A .26a Brome II 2.588 60.6 1.568a 47.48 -.010 Reed II 2.328 58.4 1.358b 41.18 .02bc let out 2.88 63.4 1.82 53.0 .18 2nd cut 2.94 59.6 1.76 53.2 .12 Alf 3.32A 60.4 2.02 61.2 .21A8ab Tre 3.36A 61.4 2.07 62.6 .24Aa Brome 2.628a 62.5 1.64 49.5 .IOABb Reed 2.358 61.7 1.44 44.2 .07Bbc 1 Not considered in statistical analysis. 78 A graphic presentation of dry matter (DM) intake of all forages is shown in Figure 1. For each cutting DM intake ranked the 1961 forages in the order of trefoil, alfalfa, brome grass and canary grass. A similar pattern was shown for the 1962 forages except that alfalfa ranked ahead of trefoil. During both years DN intake of the legumes ranked ahead of the grasses for first and second cutting forages (P (.05). There was very little difference in average DM intake of first and second cut forages especially the 1962 forages for which the first cutting was made June 1 rather than June 17 as was the case for 1961 forages. The maximum dry matter intake occurred between days 3 and 13 of the 28 day feeding trial for most forages. There was no consistant length of time required to reach maximum intake for the different forage species. Average daily intake of all forages reached a maximum after 9 days on feed (Appendix Table I). In many cases after intake of a partic- ular forage reached a maximum, a slight decrease in consump- tion followed. Consumption also decreased slightly while sheep were in the collection stalls. after removal of the sheep from the collection stalls intake tended to increase to previous levels (Appendix Table I). Some differences in dry matter digestibility of Specific forages were found (Tables 6, 7, 8). The grasses, eSpecially canary grass harvested in 1961, tended to have slightly larger dry matter digestion coefficients than the legumes. — HHH mmmaw hemcmo W fl HH H mmmpm vsoam % av — HHH seasama M” m m. _ HHH Haoaopfl — N seamen: — HH wwmhm mpmsmo t — mmmam mnmamo , u — HH mmmpw vaoam no — HM mumpm caoam d - n . 7 i H HH seasafia. m _ HH saasaae e as 7 i w — HH Hdowvae — HH Macaoaa g . i - P — H anuoedB — H anuoefie — H wmmam hamnmo t — H mmmaw mpmsmu m i , — H mamaw madam t — H mmmam macaw . m , ‘ a). _ H saaeeae F —i H sansaax — i H ancesseg , — H finenesp . 3 2 l 3 2 .1 mega anmfi gone moma Aacm:m\u30\pav mxxamw mepmz mam mfiflmm SUt Second Cut First Forage and Cutting 80 Second cutting trefoil was more digestible than the other 1961 second cut forages. Digestibility of third cutting alfalfa was low, probably because the interval between cutt- ing and harvesting was longer for this forage than for the other third cutting forages resulting in a more mature forage. First and second cutting 1962 brome grasses were more diges- tible than the other forages, (P (.01). First cutting 1962 trefoil and timothy were slightly less digestible than alfalfa, brome grass and canary grass. The 1962 second cut forages were more digestible than the 1961 second cut forages (P‘<.05). Differences in dry matter digestion coefficients for the four forage species were not consistant.(Appendix Table XIV). Dry matter digestion coefficients were determined for the 1961 forages based on feed intake 0, 24, and 48 hours pre- vious to feces collection (Appendix Table IX). Analysis of variance showed no significant difference in the resulting digestion coefficients. All data presented in this thesis are based on zero time difference between intake and feces collection. Digestible organic matter, digestible energy and esti- mated TDN values for the different forages were determined (Table 9, and Appendix Table II). Digestible dry matter, TDN and digestible energy values for all forages were correlated (I><.Ol). The correlation between % digestible energy or % TDN and % dig. dry matter were not significant (P)'.O5) for the forages harvested in 1962. This is probably due to large TABLE 9. Dig. Organic Matter, Estimated TDN and Dig. Energy of 1961 and 1962 Pure Stand Forages as Determined by Sheep (Oven Dry Basis). Dig. Organic Estimated Matter TDN Dig. Energy Forage 1961 1962 1961 1062 1961 1962 % z .% Alf I 62.5 66.2 58.9 62.4 58.2 64.5 Tre I 63.3 63.4 61.3 61.2 61.7 61.5 Brome I 61.3 66.9 58.2 63.7 55.4 63.7 Reed I 66.0 64.9 63.1 62.4 63.3 63.6 Tin.I 64.2 62.7 62.8 62.2 59.3 60.4 Alf.II 59.1 62.9 55.7 59.6 54.2 64.9 Tre II 61.7 63.3 59.4 60.9 57.1 60.7 Brome II 56.5 65.8 54.8 63.4 55.5 62.5 Reed II 55.5 60.9 53.8 58.8 50.4 59.0 Alf 2 67.6 62.8 65.2 Alf III 60.0 55.1 56.4 Tre III - 67.7 63.0 62.4 Brome III 66.0 63.2 61.5 Reed III 67.7 63.2 63.5 Simple Correlations 1961 % dig. energy vs. % dig. D.M. .85** 1962 2 dig. energy vs. % dig. 0.x .47 1961+l962 % dig.energy vs. % dig.D.M. .81** 1961 % TDN vs. 6 dig. p.m. .95** 1962 % TDN vs. % dig. D.M. .54., 1961+1962 TDN vs.% dig. p.m. .94 1 By method of Lofgreen - J. Animal Sci. 12: 359, 1953 o m V; variations between animal digestion coefficients for a single forage and a small range between minimum and maximum diges— tion values for the 1962 forages. Digestible dry matter intake/cwt dry matter nutritive value indices followed a trend similar to that of dry matter intake regardless of dry matter digestibility of that forage (Tables 6,7, 8). This is an indication that intake Lg; gg was more important than digestibility of the forage. In most cases nutritive value indices ranked the two legumes at the tOp followed by brome grass and then canary grass. There was a significant (Pz co Gama no scammenmem Hex as we om mm om me on SMOEMP comm OH .- macaw nu Monte G \x \ 23$ \ \.\ \ \q a e \ \ X \.\.\ . G \ \ 0 D 1 d mazwam .AV 1‘. p03 (flap/GI) U290 'am 87 Figure 5 .h ' 3.3 D O ’ g ' ’l”0 H ” V . ¥¥952-' 3.2 r . - o- 1935’ o o e I, 0 .p " ,. " §.l . 0 ."’° 3 ,’6 33.0 P”” o m 0 p < O l L l A I l # 1.1 1.3 1.5 1.7 1.9 2.1 2.3 Digestible Energy Intake (lb/day/cwt). Regression of Gain on Digestible Energy Intake (Each Point Represents A Sheep) Fi e 6 I a A ' n L A L A l 1.3 l.h 1.6 1.8 1.9 ' 2.0 2.1 2.2 Digestible Dry Matter Intake (lb/day/cwt) Regression of HM NVI on Dig.DM Intake (Each Point Represents A Sheep) 88 to be smaller when individual animal values were used rather than when group averages were used. This was especially true of weight gain correlations. Correlations among Z digestible dry matter and digestible dry matter intake or dry matter nutritive value indices were small and non-significant. Dry matter intake was, however, highly correlated to digestible dry matter intake (r'= +.93). Weight gain was correlated with dry matter intake, digestible dry matter intake and dry matter nut- ritive value index with correlation coefficients of +.66, +.78 and +.84 respectively. Regression of body weight gain on digestible dry matter intake, digestible energy intake,DM NVI are shown in Figures 2,3,h and 5. Regression lines were drawn in Fig.2, and 3 for 1961 forages, 1962 forages and all forages combined. The regres- sion equations, standard error of Y on X and r values for the above relations were calculated and presented in Table 11. These data indicated that there was little difference between diges- tible dry matter intake/cwt, digestible energy intake/cwt, ‘in gggg dry matter nutritive value index and nutritive value index for estimating sheep weight gain when several different forages are fed to sheep with similar average group weights. Heifer Performance Forages harvested in 1961, with the exception of brome grass III, were fed to dairy heifers. Dry matter intake was similar for trefoil I, canary grass I and timothy I while the rate of consumption for alfalfa I was slightly greater and that TABLE 11. Regression Equations for Estimating Live Height Gains from Dig.DN Intake/ and LVI and for Estimat- cwt., DH YVI ing DH NVI from Dig.DM Intake/cwt. 89 CrOp year data @guation r SY. Body weight gain lb/day (Y) and digestible 0M intake/cwt. (X) 1961 Y = -.646 + .071 X .92 .05 1962 Y = -.216 + .196 X .79 .05 1961 : 1962 Y = -.379 + .300 X .78 .07 Body weight gain lb/day (Y) and DM NVI (X) 1961 Y = -.621 + .015 X .93 .05 1962 Y = -.208 + .006 x .77 .05 1961 1962 Y = -.ul7 + .011 X .8“ .06 Body weight gain lb/day (Y) and NVI (X) 1961 ' 1962 Y = -.322 + .009 X .76 .07 Body weight gain lb/day (Y) and Dig.Energy Intake (lb/day/cwt)(X) 1961 - 1962 Y = -.280 + .252 x .72 .08 DM EVI (Y) and Dig.DM Intake (X) 1961 Y = -.l76 + 31.337 X .96 2.38 1962 Y = .485 + 29.671 X .99 .00 1961 , 1962 Y = 2.386 + 29.309 X .97 2.11 DH NVI (Y) and Dig.Energy Intake (lb/day/cwt) (X) 1961 Y = 4.83u + 29.392 X .94 2.68 1962 Y = 7.556 + 26.215 x .99 1.59 ladiia 1962 Y =_9.569 + 204010 Y ._ .95 2.70 90 for brome grass I was less. The above differences were not significant (P >.05) (Table 12). Dry matter intake of alfalfa II or alfalfa 2 and trefoil II was greater than intake of brome grass II and canary grass II (P<:.Ol). Intake of dry matter was related but not significantly (P >.05) to % fiber or lig- nin content of the forages (r = +.34 and + .45 respectively). Dry matter nutritive value index, the product of heifer rela- tive intake and sheep dry matter digestion coefficients, follow a trend similar to that of dry matter intake. Weight gains were determined only on heifers that were on trial for 28 days. Weight gains were not apparently related to digestible dry matter intake (lb/day), or dry matter nutritive value index (r= -.08). This indicates that number of heifers and/or length of the feeding trial were such that heifer weight gains on the different forages gave an inaccurate estimate of the nutritive value of the forages. Rabbit Performance Rabbits were fed the 1961 forages to determine intake, % digestible dry matter, dry matter nutritive value indices and body weight changes. Dry matter consumption ranked the first cutting forages in the order of timothy, brome grass, alfalfa, can- ary grass and trefoil (Table 12). Dry matter intake of second and third cutting as compared to the first cutting did not follow a definite pattern with respect to forage species. Dry matter intake was not significantly (P) .05) correlated to the 91 UOSGd p200 m¢m.:m 0mm.om n¢womm mmm.N ¢m.N .m>¢ n.mm a.mm m.mm comm o.au a.mm m.mm oaosm o.woa m.mm 3.0m .mp9 a.moa m.ms m.em .aaa 0% n nu.ms a.mm 3.3 nom.mm N3. om.a am. o3.m HHH comm u m.mo m.3 mam.mm u n ma. 3m.m HHH oaosm m an.aoa m.om m.m momm.mn 3H. om.m mo. mo.m HHH.osa 3 am.moa a.mm m.n «a.mm Ha. mm.m 3H. as.m HHH.MH< m 3.3 4m.am NH. mm.m 3N. ma.m ~.ea¢ N ma.ms o.nm o.3 «a.mm ma. om.a ca. om.m HH eoom m mo.mn n.3o m.m nm~.os No. mo.a ma. Ho.~ HH oaoum m «a.moa o.mm m.3 4o.mm no. mm.m mo. mo.m HH.opa m <~.HHH a.mm m.n mmaa.om so. ma.m om. om.m HH.aH< 3 s.aoa 3.He m.m «a.mm no. u3.~ mo. m3.m H.aaa 3 a.mm m.mm m.m nom3.am Ha. m3.m mm. an.m H eoom N a.mm n.3o «.m eman.am no. s~.~ NH. Hm.~ H oaosm 3 o.¢m a.mm m.m oc.as oa. ~3.~ ma. mw.m H.oue 3 a.moa 3.3m a.m m<~.om an. 3m.m no. oo.m H.eH< .asw use ne.wM\m ma.ma\m .m.m mm.wx\m .m.m .pzo\na .m.m pzo\naw‘ masses muomaom unmade: aoonn mudnpmm muomaom moosm oz .moaooam Hmsdqa unmaohmaa means an Aznv godpmszmnoo ommaom o>aumamaaoo .NH mqm 3o. v A: pesoflaemam .. tun. mu.mm\w camps“ whomdos .m> nn.wx\w campsa momnm *am. we wa\w camps“ secede: .m» ma.ma\w camped panama me. u ma.wa\m camped amass .mp ms.wa\m camped panama h uncapmaoapoo oHQsam .omszazoo ammumqmaa 93 forage content of fiber or lignin (r = +.26 and +.Ol reSpec- tively). Dry matter digestion coefficients for legumes were higher than those for grasses (P‘(.Ol) with the exception of reed II which was contaminated with corn (Table 13). Dry mat- ter nutritive value indices, % digestible dry matter and diges- tible dry matter intake were correlated to weight gain (P<:.01 - r = +.85). Weight gain by rabbits on the same forage varied a great deal (Appendix Table XIX). For example weight gain of rabbits receiving timothy ranged from 58 to 271 g. Alfalfa and trefoil resulted in greater weight gains than timothy, brome grass or canary grass (P<.01, Table 17). Weight gains during the first week on trial were less than gains during the second and third week (P.05). Based on intake/cwt, sheep consumed more TABLE 13. Dry Matter Digestion Coefficients for Pure Stand Forages by Sheep and 94 Rabbits. % Dig. DM Forage Sheep S.E. Rabbits S.E. % % Alf.I. 60.0 .7 46.2A 1.8 Tre.I 61.5 .7 46.5A 1.2 Brome I 61.9 .7 38.2B .6 Reed I 65.1 .4 38.7B ..3 Tim.I 63.8 1.1 39.8B 4.2 Alf.II 55.8 1.8 45.3A 1.3 Tre.II 60.0 .7 43.5A .8 Brome I 55.1 .7 33.8B 3.2 Reed II 55.6 .9 45.2A 2.8 Alf.2 65.1 1.1 47.1A 1.3 Alf.III 56.6 1.4 no.7B 1.9 Tre.III 64.1 .8 54.1A 1.5 Brome III 64.7 1.0 40.2 1.2 Reed III 68.6 .5 37.8B 3.3 Avg,by Specie, Alf. 59.4 44.8 Tre. 61.9 48.0 Brome 60.6 3?.“ Reed 63.1 40.6 Average 61.33' 42.6B Average of grass 62.1 39.1 Average of legume 59.7 46.0* Sheep Dig. DM vs. Sheep Dig. DM vs. Sheep Dig. DM vs. * The two values different, P< 0.01 Values with the same large superscript represent a homogenous group (Pi(.01). 1 ‘gimple Correlations Rabbit Dig. DM (all forages ) Rabbit Dig. DM (Legumes) Rabbit Dig. DM (grasses) This sample was contaminated with corn when preparing the forage in pellet form for rabbits. + .10 + .69 + .31 95 TABLE 14. Relative DM Intake of Pure Stand Forages by Three Animal Species.1 1961 Crgp Forage Sheep Rabbits Heifers Alf. I 93.0 112.6 132.1 Tre.I 101.3 96.2 124.3 Brome I 80.4 114.3 111.3 Reed I 77.9 101.7 123.7 Tim.I. 76.7 123.5 127.0 A1f.II 98.3 100.8 138.9 Tre.II 111.3 106.3 132.3 Brome II. 80.6 87.6 73.7 Reed II 69.6 104.1 91.4 Alf. 2 86.8 109.4 129.0 A1f.III 83.4 116.2 134.2 Tre.III 100. 98.9 126.8 Brome III 78.2 106.5 - Reed III 73.3 86.2 94.6 Alfim Alf. 90.4 109.8 133.6 Tre. 104.3 100.5 127.8 Brome 79.7 102.8 92.5 Reed 73.6 97.3 103.2 Average 87.1B 104.4Ab 118.4Aa 100- (g daily forage DM intake) 1 Relative intake 2 80 (wt. Kg.75) Simple correlation coefficients r Relative intake, sheep vs. heifers .59: Relative intake, rabbits vs. heifers .57 Relative intake, rabbits vs. sheep -.01 * Significant (P'<.05). 96 TABLE 15. Digestible DM Intake of Pure Stand Forages by Three Animal Species. 1261 Crgp Forage Sheep Rabbits Heifers glgg. 5 .g/Kg.25 .g/Eg.Z§ Alf. I 44.6 41.7 63.4 Tre.I 54.2 35.8 61.3 Brome I 39.8 35.0 55.2 Reed I 40.6 31.5 64.4 Timothy I 39.2 39.3 64.9 A1f.II 43.9 36.6 62.0 Tre.II 530“ 3700 6305 Brome II 35.4 23.7 32.5 Reed II 30.9 37.7 40.6 Alf.2 45.2 41.2 67.2 Alf.III 37.8 37.9 60.7 Tre.III 51.5 42.8 65.1 Brome III 40.4 34.3 - Reed III 40.3 26.0 51.9 125. Alf. 42.9 39.4 63.3 Tre. 53.0 38.5 63.3 Brome 38.5 31.0 43.8 3866 3703 3107 5203 Avg.1 42.6633 35.7st 57.90A Simple Correlation Coefficggppg r Digestible DM Intake, sheep vs. heifers .64: Digestible DM Intake, rabbits vs. heifers .67 Digestible DM Intake, rabbits vs. sheep .38 1Does not include Brome III. 97 TABLE 16. DM NVI Values1 for Pure Stand Forages by Three Animal Species Std. Std. Std. Forage Sheep error Heifers error Rabbits error Alf.I 55.8 2.0 79.3 3.0 51.9A8 2.1 Tre.I 62.3 2.2 76.5 5.8 44.7ABb 1.9 Brome I 49.7 1.3 68.9 1.9 43.7”b 3.5 Read I 50.8 4.7 80.5 1.3 39.4 1.9 Tim.I 49.0 2.2 81.0 3.4 48.9A 4.8 A1f.II 54.7 5.2 77.5 3.8 45.3A 2.4 Tre.II 66.7 1.8 79.4 3.3 46.3A 2.8 Brome II 44.4 2.4 40.6 4.7 29.5B 2.8 Reed II 38.7 2.6 50.7 3.2 47.2 3.7 A1f.2 56.7 5.4 84.0 1.3 50. 2.2 Alf.III 47.1 1.5 75.9 4.5 47.2AB 3.2 Tre.III 64.3 3.1 81.3 7.8 53.5A 2.9 Brome III 50.7 4.3 - - 43.0B 3.4 Reed III 50.3 4.4 64,9 12.2 3g‘§9 3.8 Avg, Alf. 52.5 79.0 48.6 Tre. 64.5 78.8 48.2 Brome 48.3 51.9 38.7 Reed 46.6 68.7 36.1 Avg. 53.1Ba 72.3A 44.7Bb Simple Correlations r . Sheep DM NVI vs. heifer DM NVI + .67** Rabbits DM NVI vs. sheep DM NVI + .41’* Rabbits DM NVI vs. heifer DM NVI + .66 10M NVI = 100 x (g daily forage DM intake) x % dig.DM 0 Wt.Kg. ) 2Values with like superscripts represent a homogenous group (large superscripts P<:.01 and small superscripts P < .05). ** Significant (P < .01) . 98 TABLE 17. Weight Gain of Sheep, Heifers and Rabbits Fed Pure Stand Forages. 1 61 Cro Sheep Heifers Rabbits Forage __.1b[day_ lb/dayi g/day Alf.I .19 1.93 13.5Aa Tre.I .27 1.71 12.3A Brome I .12 2.07 2.63 Reed I .16 2.38 5.2B Tim.I .13 2.38 7.1ABb Alf.II .21 1.76 9.8A Tre.II .34 1.87 13.3A Brome II -.20 - - 4.7B Reed II -.08 2.04 12.3A Alf.2 .29 1.68 12.81 Alf.III .03 1.66 10.3A Tre.III .30 - 13.0A Brome III .19 - 3.0AB Reed III .20 - 3.6B Sim le Correlation 1’ Sheep wt. gain vs. Rabbit wt. gain .23 Sheep wt. gain vs. Heifer wt. gain .29 Rabbit wt. gain vs. Heifer wt. gain - .67* dry matter than heifers (P<;.01). .However, dry matter intake per unit of metabolic size (Ht.Kg '75) shows a different rela- tionship (Table 12). The average intake per Wt.Kg.'75 of all forages by heifers was 94.8 g which was greater than 83.6 g from rabbits and greater than 70.3 g for sheep (P <.01). Relative dry matter intake of pure stand forages were compared for three different animal species (Table 14) and were similar to those found with actual dry matter intakes. Average relative intake of the forages was 118 for heifers, 104 for rabbits and 87 for sheep. The same formula was used to calculate relative intake 99 by the three animal species. Heifers consumed more diges- tible dry matter per Wt'Kg..75 than did sheep or rabbits (P< .01) (Table 15). Dry matter digestion coefficients for 1961 eXperimental forages as determined by sheep and rabbits were compared (Table 13). Digestible dry matter coefficients by rabbits ranked the legumes above the grasses (PM<.01) whereas sheep tended to give larger dry matter digestion coefficients for the grasses. The latter difference was not significant (P;>.05). Forage consumed by sheep had larger dry matter di- gestion coefficients than the same forages fed to rabbits (I*<.01). The correlation between rabbit and sheep digestion coefficients was not significant (P;>.05). Considering the seven legume forages alone, the correlation between digestion coefficients for sheep and rabbits approached significance (r = +.69). Dry matter nutritive value indices (DM NVI) as deter— mined by sheep, heifers and rabbits were calculated for the dif- ferent forages (Table 16). Sheep vs. heifer or rabbit vs. heifer DM NVI were significantly correlated CP< .01). In con- trast rabbit and sheep DM NVI were not found to be significantly correlated (P;>.05). Sheep DM NVI for first cutting forages ranked trefoil first followed by alfalfa and then the three grasses. Heifer DM NVI ranked timothy, canary grass and alfal- fa the top followed by trefoil and then brome grass. Rabbit DM NVI ranked alfalfa and timothy at the tOp followed by tre- foil and brome grass with canary grass last. Thus there did 100 not seem to be a consistent ranking of the forage species by the different animal species. However, significant positive correlation coefficients indicated some relationship between DM NVI as determined by sheep, rabbits and heifers (Table 16). Sheep weight gains did not appear to be related to rab- bit or heifer weight changes (Table 17). Rabbit and heifer weight gains tended to be negatively correlated (Table 17). Sheep and rabbit weight gains were significantly (Pi<.05) cor- related to digestible dry matter intake and dry matter nutri- tive value indices (DM NVI) (Table 18). Sheep dry matter intake appeared to have more effect on weight gains than % digestible dry matter. The reverse was found with rabbits. Heifer weight gains were not related to DM NVI or digestible dry matter intake/cwt. This would indicate heifer weight gains were inaccurate even though obtained over two 2-week periods following a 10 day pretrial on that forage. In Vitro Fermentation Trials Experimental forages were incubated with rumen fluid to determine gp,z;ppp dry matter disappearance and its relation- ship with animal performance. Ip ygppp dry matter disappearance values for 1961 and 1962 forages are an average of four repli- cates (Appendix Table XXIII). Analysis of variance was used to analyze Ag zgppg dry matter disappearance as affected by forage Species, fermentation time and forage cutting (Appendix 101 :o. va V 382383 .313. eases“ an massed zo.wda so .mao a H>z mm. in. 88mm. ##nm. 00.! *tm&. OH. **om. **mme MH- wé. Nd. mmol mm. NJ. *tmm. mo.I *tmm. oxmpfid H>Z HHQO Oxmpfid H>z SQ SQ apanndm maoaaom acesm “mommaom Howdy modooam Hmsaad means an mowm show no msam> o>dpaau3z opmsflm>m on new: danceaao Hmoo>mw wooed maoaumaeaaoo camsam .mH mamas 102 Table XXIV). Cutting and fermentation time significantly (P< .05, and P<;.01 respectively) affected ;p_gippp dry matter dis- appearance of the 1961 forages. Forage species and fermentation time were found to affect gp;zgppp_dry matter disappearance (I’<.01) for the 1962 forages. Forage species and fermentation time interactions were significant (P<<.01) for both crops. This would indicate that rate of dry matter disappearance for all forages with time was not the same. Different rates of dry matter disappearance are evident in Figures 7 and 8. Dry matter disappearanme after three hours of fermentation was great- er for the legumes than for the grasses with the exception of alfalfa III (Figs. 7, 8 and Appendix Table XXIII). However, dry matter disappearance after 48 hours was greater for the grasses with the exception of first cutting alfalfa. Three or six hour fermentation values ranked the forages differently than the 36 or 48 hour fermentation values. The correlation coefficient between 6 hour and 36 hour fermentation values was not significant (r = + 0.34; P;>.05). The forage species and cutting interaction terms were significant (P< .01) for both crepe (Appendix Table XXIV). This indicates that total lphygppp, dry matter disappearance of different forage species did not all change the same with first, second and third cuttings. Simple correlation coefficients between sheep performance and Ag 11339 dry matter disappearance were calculated for 1961 for- ages, 1962 forages and all forages (Table 19). Dry matter intake, digestible energy intake, $2 vivo dry matter nutritive value 103 oozodpsoo u u 3m. mm.. 30. 38. am. am. 3m. mm. .sse\exssso awaese .woo N8. Ne.. 38. mm.- we. on. H3. am. am. we. sosm preamp. mm. mm.. mm. Hm.u ma. ma. mm. He. no. me. H>z so sea» sH u u u 83.: N0.. mo. ms. mm. me. He. H.sse\easssa so aaoso m3. mm.. mm. Hm.u 3H. om. om. am. mm. mm. .ssexsssssa so “moo no. mo. oo. me. we. ma. 3a.- mm.n ma.u ma.- .wae so o>a> 8H a Hm. am.u mm. 33.- 00. me. am. om. 3a. we. .sse\exsssa 2o aooso ooao mama .1: u u n mm. mm. mm. mm. on. so. no. HHsz 2o osfiwrsH - u u om. me. an. mm. am. an. m3. Hzo .mae can» so a - u - ao.- mo.u mm. ma. on. em. mm. H.sse\easasa 2o aoaso . u we. we. ea. 83. mm. mm. am. we. ase\oasssa amaess.wao on. om.u ma. am. am. on. mm. mm. mm. mm. sasm semawm Ne. e~.u ma. em. mm. mm. mm. 3m. mm. as. H>z so cede so ma. no.1 a. He. mm. on. mm. mm. on. 36. .aze\osssso so “Moo 3H. mm.u 8. am. on. mm. m3. an. on. H3. .moe so oeoe so a on. mfi.n mm. mo.l HH.I mm. mo. 53. :w. m:. .930\mxmpoa 2Q haama ooao Hema Had «.mmu gaslam,.¢a3 .as 4mm 14a: .as 4o: .as u some maom x w m: 0m 3m ma NH w m oHom 00H: m .mpmo moamsaomaem Amonm cam moamomoaamman 2Q noupmpaosomm oopa> mm.aoosuom moodumaooooo oaasdm .mH mqm mo opmopaam mm. n mama + Hema “me. u Homo now. u mama a sea o «a .hm: codename maHmMHm me made: acnpmaam> .asasoomd smash mom axon m mm 08mm mascoooamm a“ mopmoemsonomo odosaomm men on new new copooaoooa I u on. ma. ma. mm. mm. mm. om. ow. .p30\mxmpnfi awaoam.mdn m3. am.u 38. me. am. mm. mm. am. we. on. same sswaww we. mm.n ms. Ha. mm. mm. mm. mm. me. am. H>z 2o asap sH om. mm.u an. ma. am. an. an. as. mm. mm. .szexeasasazohmdo mm. no. an. 38. me. mm. on. mm. 3m. mm. .mae so seas 2H a H3. mm.. mm. no. 00. an. «3. me. 35. we. .sse\eassso so aaaso moss Nemauaoma essaosoo ado N emu .as am, «as qu l.as .mmwl.as .as 14mm| - mess aoem s e w3 em 3N mo «H e m eOw .as m QMDZHBZOO WH mnm¢9 105 m3 Nd AU 0 0 radios mcdoosu [F on aasosoe area 080me anemone mmamwfl< ' ’-|-u|- "l \I. s... 4: i 2. 1 a 0.. ..J .)< .u. of. . Impw.. ramp..ac ntg1§13?.~wo;fl,ofléo 0: Nb VH F F J- :oaomoCmsoom mo mason (\1 H on 3m ma q \s 0 fi. AU\\\\\\\\\ \ w oaswoa j O ‘n on pearance an ‘ a "| EN % 106 :oopmocmmimm no mass: mommoox moaoosw vaccmu moma mo ocamammaQMmflo an oooiw 0H m3 ad pm on in ma m. o q a d d u C - q C\. . Kim D\0 E mCCLL ‘ x m omswfim on on 107 indices and body weight gains were all significantly corre- lated with 6 hour 1p zippp_dry matter disappearance (P4:.01). The correlation coefficient of animal performance and 6 hour dry matter disappearance was higher for 1962 forages than 1961 forages. This difference may be due to larger var- iations between replicate dry matter disappearance for the 1961 forages. Dry matter disappearance standard deviation, standard error and % coefficient of variation for 1961 for- ages were 4.42, 2.21, 11.18% and for the 1962 forages, 2.27, 1.14, and 5.13% respectively (Appendix Table XXIV). Daily intake/th and other lp,zgzp criteria of intake were more highly correlated with 6 hour fermentation values than with other fermentation intervals. Correlation coeffic- ients between 1p,gizp_% dig. DH and gp‘zippp DH disappearance were largest for the 36 hour fermentation values. The product of 6 hour x 36 hour dry matter disappearance divided by 100 was termed lpgzgppp_dry matter nutritive value index. Combin- ing the two time values, one highly related to intake and the other to digestibility into one term, might result in a higher correlation with comparable 3p;1;ppp measurements. However, six hour dry matter disappearance values resulted in larger r values when correlated to animal performance than did ip,glppp nutritive value indices and also resulted in regression equat- ions with smaller standard errors of estimate (Table 20). Regression equations with their standard errors of Y on X were calculated for predicting animal performance from ;p TABLE 20. Regression of Forage Intake, Digestibility and 1p Vivo NVI on In Vitro DM Disappearance. (1961 and 1962 Forages). 108 9. 10. lg vivo DM NVI (Y) vs. 6 hr 3p vitro DM disappearance.(X) Y = 13.2 + 1.395 X In vivo NVI (Y) vs. 6 hr DM disappearance (X) 7.032 + 1.55 X .lp vivo DM NVI (Y) vs. (;p_vitro NVI) (X) Y = 26.6 + .017 X lg vivo DM NVI (Y) vs. 6 hr DH disappearance due to inoculum (X) Y = 43.203 + 1.926 X Digestible DM intake/cwt (Y) vs.6 hr ;p_vitro DM disappearance (X) Y = .462 + .044 X Digestible Energy Intake/cwt (Y) vs. 6 hr 1p vitro DM disappearance (X) Y = .220 + .051 X DN Intake/cwt (Y) vs. 6 hr 1p vitro DM dis- appearance (X) Y = 1.020 + .062 X DM Intake/cwt (Y) vs. 6 hr DM disappearance due to inoculum (X) Y = 2.253 + .1036 X % Digestible DM (Y) vs. 36 hr lg vitro DM disappearance (X) Y = 38.90 + .435 X Wt. gain.1b/day (Y) vs. 6 hr ;p_vitro DH disappearance (X) Y = .292 + .015 X .90 .77 .79 .75 SYIX 3.77 4.04 5.24 5.33 109 zlppg dry matter disappearance data (Table 20). Daily intake of dry matter, digestible energy and diges- tible dry matter were predicted from przlppg dry matter dis- appearance values with standard errors of .30, .14 and .15 lb reSpectively (lines 5,6 and 7, Table 20). The standard error for actual dry matter intake/cwt of an individual forage by four sheep ranged from .07 to .24 lbs while the standard error for observed daily digestible dry matter intake/cwt ranged from .02 to .17 1b. The standard errors of estimate for weight gain based on 6 hour fermentation values, lp.zlzp dry matter nutritive value index, 1p Kipp dry matter intake or ;p 1113 digestible energy intake were .07, .06, .07, and .08 lb reSpectively. Thus it was possible to use gp,zgppg fermentation data with some degree of accuracy to predict intake of energy, intake of dry matter, dry matter nutritive value indices and resulting body weight gain. The standard errors are, however, large enough so that this 1p.g;ppg method would not detect small differences in nitritive value of forages. Soluble carbohydrates and three hour buffer-soluble material were compared to animal performance data. Correlation coefficients for soluble carbohydrates and animal performance data (Table 19) were negative but not significant (P)..05). Three hour buffer soluble dry matter was significantly corre- lated to ;p_gggp_dry matter digestibility, digestible dry matter intake/cwt. and 3p vivo dry matter nutritive value 110 index (P'<.01) but the correlation coefficients between sheep performance and lp‘gippg dry matter disappearance were larger in all cases. Duplicate samples of a standard alfalfa* were fermented for each time interval with each fermentation trial (with each days trial) to make possible a correction for day to day variation (Appendix Table XXV). Corrected pp pgppp dry matter disappearance values did not increase the correlation coeffic- ients between lp_z;ppg dry matter disappearance and sheep per- formance (Table 19). The coefficient of variation for 1962 corrected fermentation values was 5.95% as opposed to 5.13% for the non-corrected values. Duplicate dry matter disappearance values for standard alfalfa hay were obtained on 6 different days with seven dif- ferent fermentation periods for each day. Three missing values were determined according to Snedecor (233). Day to day co- efficients of variation for 6 and 36 hour fermentation values were 7.06% and 4.41% respectively. However, if values for one day, which are nearly two standard deviations from the mean, are eliminated, the coefficient of variation drops to 1.68% and 3.53% for 6 and 36 hr dry matter disappearance values respectively. Coefficient of variation between duplicates was .55% and 3.09% for 6 and 36 hour fermentation values reSpect- * Standard alfalfa hay from Kansas used in cooperative pp vivo and pp vitro experiments by several universities. 111 ively. Several variations in the lp,1;ppg method were studied. Dry matter disappearance of forage substrate after three hours of fermentation with and without rumen inoculum was com- pared (Table 21, and Appendix Table XXII). Increased dry matter disappearance due to the action of rumen inoculum was larger for legumes than grasses (P‘<.01). TABLE 21. DM Disappearance When Buffer was Sub- stituted for Rumen Inoculum and Incubated for 3 Hours. 1961 Crop. 1962 Crop __ Buffer Rumen Buffer Rumen only inoculum only inoculum __Forage. Crop. % g ~ '_ Alfalfa I 28.4 29.2 29.6 36.5 B. Trefoil I 23.8 28.4 26.3 30.5 Brome I 21.6 20.9 24.6 25.5 s. Canary I 24.9 26.4 26.2 26.1 Timothy I 22.0 20.0 24.4 26.0 Alfalfa II 21.8 29.0 26.6 33.7 B. Trefoil II 22.6 25.0 24.8 32.0 Brome II 16.8 15.2 22.2 23.1 R. Canary II 17.9 13.9 20.8 20.8 Alfalfa 2 27.0 30.1 - - Alfalfa III 17.8 23.0 - - B. Trefoil III 26.0 28.2 - - Brome III 22.6 24.5 - - R. Canary III 23.2 24.0 - - The negative values obtained with the 1961 (Table 21) forages may be due to variations in residual rumen inoculum added to the flasks. The change in 3 or 6 hour dry matter disappearance due to added rumen inoculum for all forages was correlated with intake (r = + .79, P<:.01, Table 22). TABLE 22. Simple Correlations Between DM Disappearance Due to Rumen Inoculum and lp Vivo DM Intake, DM NVI and Weight Gain. 112 1961 DM intake vs. 3 hr DH disappearance due to rumen inoculum DM intake vs. 6 hr DM disappearance due to rumen inoculum DM intake vs. 12 DM disappearance due to rumen inoculum DM NVI vs. 6 hr DN disappearance due to inoculum Weight gain vs. 6 hr DM disappearance due to inoculum 1962 DM intake vs. 3 hr disappearance due to rumen inoculum DM intake vs. 6 hr disappearance due to rumen inoculum DM intake vs. 12 hr disappearance due to rumen inoculum DM NVI vs. 6 hr DH disappearance due to rumen inoculum Weight gain vs. 6 hr DM disappearance due to rumen inoculum 1961 plus 1962 DH intake vs. 3 hr DM disappearance due to rumen inocu- lum DM intake vs. 6 hr DM disappearance due to rumen inocu- lum DM intake vs. 12 hr DH disappearance due to rumen inoculum DM NVI vs. 6 hr DM disappearance due to rumen inoculum Weight gain vs 6 hr DM disappearance due to rumen inocu- lum .63* .79** .79** .70** .77 .56 If only 1962 forages are considered the correlation coefficient between dry matter intake/cwt and 3 hour or 6 hour dry matter disappearance due to rumen inoculum or microbial degradation was + .97. All the correlation coefficients between dry mat- ter intake and dry matter disappearance due to rumen inoculum (Table 22) were larger than those determined for total ;p_vitro 113 dry matter disappearance (Table 19). Dry matter nutritive val- ue index and weight gain correlation coefficients were larger when total 1p.1;ppg dry matter disappearance was used rather than dry matter disappearance due to rumen inoculum with the excep- tion of weight gain for the 1962 forages. If these differences in rate of digestion are found lp 3119 and rumen fill does affect intake then early rate of degradation may have a large affect on pg.l;p consumption of any all roughage ration. Brome grass II (1962 crOp) was incubated at all time intervals with and without rumen inoculum (Table 23). After 3 hours of incubation with buffer 23.4% of the dry matter was filterable and this increased up to 28.8% after 48 hours of incubation compared to 63.7% for fermentation with added rumen inoculum. TABLE 23. DM Disappearance (fl) When Buffer was Substituted for Rumen Inoculum and Incubated for Various Times Using Brome II - 1962 CrOp. Time Hour (Single Observations) jL 6_ 12 18 24 #36 __48 Buffer only 23.4 25.0 25.5 26.1 26.8 27.8 28.8 Rumen inoculum 2341 25.1 33.2 40.8 49.9 5719 63.7 Sulka flock was added to the ;p_zlppp fermentation flasks as the only substrate on two different days (Table 24). Digestion of sulka flock started after about 12 hours of fer- mentation. It is difficult to eXplain the long "lag" period for dry matter disappearance with a sulka flock substrate. 114 TABLE 24. DM Disappearance (a) When Sulka Flock was Used as Substrate in Usual Pro- cedure. Time Hour (Single Observations), .3 76’ 12 18 24 p367 '48 Day 1 0 O 1.5 14.1 29.4 43.2 54.5 Day 2 0 0 0 6L2. 25.8 42j8 __39.8 _gp vitro dry matter disappearance using different vol- umes of settled and nonsettled rumen fluid were studied (Table 25). Ten or 60 ml of settled rumen fluid resulted in disappearance of similar amounts of dry matter after 24 hours of fermentation and there was only slightly less dry matter disappearance with 10 m1 of rumen fluid after six hours of fermentation. A similar relationship was found between 10, 24, and 60 ml of nonsettled rumen fluid. Using 10 or 60 ml of settled rumen inoculum resulted in slightly less dry matter disappearance than equal amounts of nonsettled inoculum. After six hours of fermentation, 60 m1 of settled rumen fluid resul- ted in slightly more dry matter disappearance than with 10 ml of nonsettled rumen fluid. In vitro dry matter disappearance for canary grass I (1961 cr0p) and standard alfalfa were similar when 60 m1 of nonsettled or 24 ml of settled rumen fluid were used (Table 26). Values for the standard alfalfa indicate that dry matter disappearance values were about the same for both methods or possibly slightly higher for the 24 m1 of settled rumen fluid. 115 .cm>osmo Hmaompms mpmHsoHooma on» cam manomm on omzoaam odsaa smegma I NHIOH om H 3 oSHm>NMQMHum>oomoo qo: a.mn m.om m.me m.mm m3 w.om a.m3 a.mn o.ae em m.m3 m.o3 3.m3 n.an 3m “.83 m.33 a.m3 0.83 ma n.m3 a.mm o.am a.mm NH a.mm a.mm a.mm a.mm m s.om m.3m a.mm 3.8m m 1mm a. we as usual aooappOm ooaopomnaoa Hcoaupom coauuomlao: mafia )1 whammad ULGUQMpn .dwmmdnw mango finesse poem aoflpmusosaom asasoosH omega ooappem go as 3N oo emaupomasoz mo as on mafia: mommaumosm 039 mo cosmommaammdm 2Q .wN mqmmB amoumodfldua.: mo .m>4“ m.a3 m.mm m.a3 3.Hm a.m3 m.mm a.m3 a.am m.m3 m.mm oessaeeoosedo 2o 3m a 3m 8 3m 0 3m e 3m 8 Amaze can» seapmasesaea on 00 om om 0H OH on ow OH OH A.Hsv com: asasoosH an as mwwmmumm .esaooonH spasm coaupomaaoz use eeaasom seem mo hessooa useaeooao made: maammad compsmpm no cosmomoaammdn nouns: ham Assesseeusoz .mm mooae 116 Thus 24 ml of settled and 60 m1 of nonsettled rumen inoculum resulted in similar dry matter disappearance values. Allow— ing the particulate material in the rumen inoculum to rise and be discarded resulted in decreased dry matter in the remaining portion (Table 27 and Appendix Table XXVI) as would be eXpected. The 1962 fermentations were carried out with 24 ml of settled rumen inoculum compared to 60 m1 of non-settled rumen inoculum for the 1961 fermentations. The non-settled inoculum contained 0.45% non-filterable dry matter whereas the settled inoculum contained 0.10% non-filterable dry matter. Thus non-filterable residual dry matter from the 1961 rumen inoculum per flask was 0.270 g in comparison to 0.024 g in the inoculum added to each fermentation flask in 1962. TABLE 27. Total and Non-filterable Dry Matter in Settled and Non-settled Rumen Inoculum. Total Non-filterable _p DI‘I DH g . o Non-settled 2.09 0.45 Settled 1.82 0.10 Slaughter Trials - 196lpand 1 62 Previous trials indicated that sheep would consume more of some forage species than others. Forages selected for use in the slaughter trials had a large range in average daily 117 consumption when fed to sheep (1961 second cuttings 1.78 to 3.87 and 1962 first cuttings 1.80 to 2.77 lb/cwt - Table 28). For both crops the average consumption of the legumes were greater than that of the grasses (PM<.01) with the exception of timothy 1. Dry matter intake of alfalfa II was greater than that of trefoil II (P<:.05). Dry matter digestion coeffic- ients for the forages were similar with ranges of 55 to 60% for 1961 forages and 62 to 65A for the 1962 forages (Tables 6 and 7). Thus the variations in consumption of digestible dry mat- ter were similar to those of dry matter intake. Simple corre- lation coefficients between weight gain and dry matter intake/ cwt or digestible dry matter intake/cwt were significant (P< .01) when both 1961 and 1962 crOps were considered (Table 31 lines 6 and 7). The correlation coefficient between dry matter intake and dressing % was not significant (P>».05, Table 31, line 5). These relationships however, are based on a 14 day feeding period without a pretrial period. Differences in fiber intake were similar to those of dry matter intake (Table 28) since all the forages contained 29 to 33% fiber with the exception of 1961 alfalfa II which contained 38.4% fiber. The variation in dry matter intake and its content of fiber resulted in similar fiber intakes for sheep receiving alfalfa II and trefoil 11. Daily lignin intake varied from 40 to 171 g and 28 to 110 g for the 1961 and 1962 forages respectively. Lignin 118 oozmemoo man can .m>< mHeN mnm NMH smm mmm H emmm mmom mam emm mom HH emmm «men men we: mHm nan H .sae mHsm mmm Hem «mm HH osowm «HH: me: man an: om: H .mp9 «new emu coo man HH.ose «mH: mm: sen an: own H .aHe «can mno we: 3mm HH.oH< Ame mxman gonna Nn.H mo.H .w>4 naH.H em.H we. me.H 3H.H H comm ooH.H so.H wN.H eH.H HH emom mHe.H om.H em.H mm.H we.H H .eHe 0mm. so.H mm. Hm. HH maoum mHe.H os.H sw.H mm.H me.H H .oae < mom.H om.H mo.H Hn.m we.H H emom mmo.m am.H sm.m OH.N HH emom < a NmmH a .m>< .1: qwemH AnopsmsmHm o» aoHam when m pom .w>4v chosen: an.pzo\mxmch gammaa ems smpHm .zm.maa .zo sHamo .mm mamaa 119 .pounwsmam cam wchomm ummH cmmzumo Hm>aouaH cu mpcmom H we we .msa 9mm om wH mm mm H emom no: on a: o: HH emmm com w: an me an H .569 can He an mm HH oaosm «OHH mOH HOH sHH NHH H .mp9 4HsH meH NmH moH HH.ose mma mm mm mm Hm H .oHa momH omH eOH mmH HH.eHa “me mansz :Hnmaq 14s: NH (qua e [was 0 o 11W H o H man m>< HemH 120 consumption from trefoil was greater than that from alfalfa which was greater than that from the grasses for each year (P.05). The correlation coefficient was significant (r = +.88 - P‘<.01) 12 hours after feeding. The regression for- mula based on dry matter % of rumen contents 6 hours after feeding for all forages was Y = 11.508 + .847X (Syox = .9l%) where Y = % dry matter of rumen contents and X = dry matter intake/cwt. The dry matter % of rumen contents of sheep slaughtered 12 hours after feeding was significantly lower than that of sheep slaughtered 6 hours after feeding (P‘<.05). The % fiber and lignin content of rumen digesta expressed on a dry matter basis changed very little from 6 hours to 12 hours after feeding, but did show a slight increase with time after feeding. .acpnwzmHm use wnHocmm pmmH ammzucn Hm>ampsH on mammmn H 1 .23: 8.8 a; oem.m m:.OH NH.m m:.s om.m H comm oeo.s Hm.w mm.m Hn.o HH coma QHe.m mo.OH mH.0H om.m em.m H .eHe mom.HH mm.NH 53.0H mm.OH HH maopm «Ha.mH aw.om w:.mH mo.HN m:.mH H .ose 4mm.uH NH.mH mo.wH mm.aH HH .mp9 mmo.eH om.sH oe.eH :e.eH ma.mH H .oHa «mo.mH oe.mH mm.mH mo.mH HH .eHa anqu w mm.ma m:.me .msa mea.mm ou.~e mm.oa so.mm am.um H comm mem.:m Hm.mm Nn.mm mn.mm HH emmm mma.mm mm.mm ms.mm mm.em mo.um H .eHe mo.mm om.oe wH.mm Hm.em HH meetm «oe.a: es.on mm.ee mm.on mm.:: H .oua nmaHe.He m:.me Nw.mm mH.He HH .mp9 ems.se oo.om No.5: me.m: mm.ma H .oHa maeo.me Hm.me He.ma 00.8: HH .oHe smpHa w mmm.HH we:.MH .m>< men.0H as m se.e do.HH sm.mH H comm mNN.mH we.mH mo.NH mm.mH HH comm asm.mH mm.mH as.NH em.eH :Q.NH H .eHe mwm.mH eH.NH NH.mH mw.NH HH oeonm <3m.mH mm.mH mH.NH om.:H mm.mH H .oue .05 Table 31 line 3). These data might indicate that the consumption of canary grass was limited by rumen fill. However, this line of reasoning is not in accord with the data obtained on the other forages. Total dry matter in the rumen of sheep fed trefoil II and canary grass II (1961 forages) was high and about equal (Table 30). Brome grass II and alfalfa II were similar in dry matter fill, yet had very different intakes. Alfalfa I and trefoil I (1962 forages) had similar intakes yet were low and high in rumen fill respectively. Canary grass 1 with low intake resulted in an intermediate dry matter fill 6 hours after feeding. The correlation coefficients between dry matter intake and amount of dry matter in the rumen 6 hours after feeding were not significant (P) .05 Table 31, line 1). Dry rumen contents 12 hours after feeding were related to dry matter consumption (r = +0.76 P<;,05). The r( J 12’ omstpcoc wmm 3mm .m>< mom awn mmH mom :Nm H emom maemm 6mm man man HH ewmx mmm mom can :0: 03m H .sHa anmN mmm meN HmN HH macaw mHe mmm mmm mmm BN2 H .mp9 eon: new HH: mH: HH .mp9 can no: 3mm own men H .oHa amass: mm: mam Hem HH .oHe ”my psmpfioo .Hmndm £335 mama .m>< use mmm mum onH :mm H comm m< H.pn NH H.s: e .w>< H.ss e memmuom Nme mmwwpom meH .Qomnm mo pzo\sstHA can .ponHm 2Q .mummeQ pox no unoppoo nossm .om mamaa 124 .ampswsmam cam wchmma pmma scozpmn Hm>pmpsH on maowcm use om sostH mmmma mOH mm mm om mm neH mmH mmH mHH HNH me He mm Nm NNN msH :HH ONH HHHH .w>< new: .BHB .oae .MH< dmv pmopaoo :Haqu om m4 nmd Hm Hod me we 50H mNN meH mm mm moH mmH Hm om mmH NHH HH comm HH msoam HH .mp9 HH .mafi ampawmzoo omlmmmne 125 later relation was based on only four forages and eight sheep fed the 1962 forages. Rumen dry matter fill was 744 g 12 hours after feeding when all forages were considered which was less than 931 g 6 hours after feeding (P<:.05). The amount of fiber and lignin in the rumen was positively related to level of dry matter consumption (P<:.Ol, Table 31, lines 19 and 20). Forages that produced a large rumen fill of fiber and lignin were those that ranked high in dry matter con- sumption (Table 29). Thus 6 or 12 hours after feeding there did not appear to be a proportional build up of fiber or lignin in the rumen of animals receiving the grasses which were con- sumed in smaller amounts than the legumes. Rumen retention time of dry matter, fiber and lignin was shorter when sheep received alfalfa or trefoil rather than the brome grass or canary grass forages (P<'.05, Table 32). Rumen retention time of dry matter was about six-tenths of a day for the legumes and one day for the grasses. This indicated that the average "particle" of trefoil or alfalfa stayed in the rumen for six-tenths of a day. Rumen retention time of dry matter was less in sheep receiving alfalfa or the trefoil than those receiving brome grass or canary grass (P Auzo\wv pmnHa mo musmpsoo smssm .mH **mm.- ee.- *.nm.- .wem.u Hm m» Apzo\nHe massed 2o .maa .mH ..as.- .ms.- .Hs.- ..N@.. m .m» As20\m a masses posse .NH **ms.- was.. He.- **em.- Nm mp Ap30\m a mxmsca :fieaan .eH mm. m:. ma. mm. mm m> psmHonmmco consummaamch amnHa spasm .mH ..ms.- 30.- .Hw.- ..sa.- mm+Nm m» Aszo\sHe tween“ 22 .eH **Hm. ##mm. ##30. *tmm. m m> Nm .ma **mm. *amm. *twm. atom. mm m> Hm .NH t*mm. *amm. *tmm. *amm. m m> Hm .HH **Ns.- 50.- em.. wwma.u Ammo tonne mo osHp :oHmeums amass m> Hp30\nHv oxmmsH 2Q .OH ##Hu.l Nw.l *abm.l ##WB.I Ammv SHGNHH mo esHu soHpccme Smash m> Huso\nHv mxmeH 2Q .m *tmw.l m0.l *Nw.l **wm.l Aamv 3Q mo csHp soHuccpmp amass m> szo\pHv mxmeH :Q .m **mm. No. we. **Hm. Aame\sHv gnaw pgmaoz w» Aszo\sHv massed as .saa .s *gme. mm. He. **om. Asme\nHV eHmm semHmz m» Apzo\pHv mxmucH z; .e mm.l mm. mm. 33.: R qumwmpo m> Apzo\nHv mxmeH 5Q .n mN. was. mo.u mm. Aszo\eHv mucousoo :mssa ape m>Apzc\nHv oxmucH an .wHQ .3 Ho.a ma. mo. no.u Au30\nHv mudmpsoo amass pm: m>Apzo\nHV cxmpsH SQ .m *tmnn **m H 30.- *wwm. muemunoo amass ea am a m>Asz\nH mxmsea an .N mm *w do. . Hugo nag musmpsoc smszp an m>Apsc\oH oxmeH 2: .H .2 e :3 NH .2 ml was 0 Nme+meH Nema wilvlu .mmmemoo HQOH a cstHA no amnHm .ZQ mo announce amasm cam 22 no mxmpGH semapmm mpsmHOHmmmoo QOHpmHmaaoo cHasHm .Hm mqmaa l AHo. vac unmeaoHewam w: Hmo..vmv peaoHoHcmam * .ampnwsmHm cam wsHommm pme consume Hm>acpsH msHp cu mpcumm H um. I I I speak nH msHp QOHpsouma amQHm m> cch IooHHoc Hence an mpSmHonmcco :oHpmmmHo panm .mm *tflm. #*mm. **:m. *aom. GHQwHH mo va musmpsoo amass m> Apzo\wv oxmeH :HsmHH .Nm twmm. wwem. on. *me. smnHa mo va mumousoc smash m> Hp20\mv mxmusH aanm .Hm ##05. **mm. **mm. *tmm. A930\DHV campsH 2Q w> A930\wv sHsmHH mo muncpsoo spasm .om NE mm in; ,NH 4.3 m was e I. m H+H H N mH 11ml! Inmsneamm 0 Ho H anDZHazoo Hm1namawl ad a: 1. omssHpsco om.H mm.H .mp4 m:. N mm.N mH.N mm.H Ne.N H emmx 42m. H Hm.H 2H.N we.H HH coma nmamm. H me.H os.H mm.N sw.. H .aHa mmaoe. H as.H mm.H me. H HH maopm mom. H mm.H mm.H om.H mm.H H .msa ammH. H H:.H No. no. H HH .msa men. H mo.H em.H oa.H me.H H .eHa gee. H mo.H eN.H em. HH .eHa gunmaH no msHp nonmemaom om. so.H .w>4 maeN.H on. H HH.H 5H.H mm H comm asN.H H:.H 0N.H ON.H HH eeom nmamm. em. mm. sN.H mm. H .sHa «mamo. H wH. H om. 0H. H HH oaosm nmaoo. H mm. mm. NN.H No.H H .ose nmmmm. no. H me. we. HH .mp9 mew. am. am. mm. mm. H .eHa mms. as. mm. mm. HH .eHa pmon mo msHp QoHuzmumm QC“. ammo owbww «am. am Nm. Hm. so.H H comm st.H mN.H mo.H MH.H HH ewmm meme. me. me. HH.H as. H .eHa 400. H mm. om. MH.H HH macaw new“ mm. we“ we. mm. H .msa mew. mm. em. on. HH .mp9 mHm mm mm Ho. mm. H .eHa mow. wm. Nu. me. HH .aHn as so made :cfisempmm i. qw>£ a: Nfll was w .w>< N.A£ w wommpom NmmH m mwmpwom Hem H Al ‘1‘ I‘ll .mama sH HaHQwHH cam aanm .29 ac osHB :oHpSepmm spasm .Nm mamas 129 acpnwsmHm cam mchomm pmmH smczpmn HmbhmusH on msmwmmN hmm\pzo\nmpmm pamsqumsoo .nH n usmsqumsoo mo osHp :oHuzmpom pzo\:mssn sH psoSpHemooo an H ¢ sstaH gonna an emmwmm sagas ,mm« 4 mummnom Nme mammaom HmmH QMDZHBAOO NM mqmde 130 0.88 to 1.26 for alfalfa I and canary grass I. This differ- ence was significant (P‘<.01). Sheep fed brome grass II had longer retention time of fiber than those fed alfalfa II (P (.05), and rumen retention time of fiber from canary grass I was longer than that of trefoil I or timothy I (P<:.05). Rumen lignin retention time was less for sheep receiving the grasses as compared to the legumes (P (.01) with the excep- tion of timothy I. Average rumen retention time of dry matter from the 1961 forages was less than that of fiber (P (.05) and both less than that of lignin (P'<.Ol, Table 32). A Similar trend was found for rumen retention time for the 1962 forages with the excep- tion that the difference between dry matter (.77 days) and fiber (1.02 days) retention time was not shown to be signifi- cantly different (P,>.05). Average retention times indicate that some more soluble portions of the dry matter passed "through" the rumen faster than fiber and lignin. Significant negative correlation coefficients between daily dry matter intake and rumen retention time of dry matter, fiber and lignin were obtained for the 1961 (P<:.01) and 1962 forages (P‘<.05, Table 31, lines 8,9 and 10). Thus as dry matter intake increased, the rumen retention time of dry matter fiber and lignin decreased. Also as fiber and lignin intake increased, the reSpective retention times of fiber and lignin decreased (P<;.01, Table 31, lines 16 and 17). Retention times of dry matter, fiber and lignin were 131 all positively correlated (P<:.01, Table 31, lines 11,12, and 13). Although retention time of fiber, for individual animals, in the rumen varied from .59 to 1.41 days, there was no cor- relation between rumen fiber digestion as determined by the lignin ratio technique and rumen retention time of fiber (Ph>.05). Total fiber digestion as determined by collection trials was not related to rumen retention time of fiber (P >.05, Table 31, line 23). Lignin ratio technique was used to determine dry matter and fiber digestion from the rumen and the lower large intestine and were compared to the total collection values (Table 33). Dry matter disappearance in the rumen for the 1961 forages ranged from 67.7 to 78.9% of the total dry mat- ter digested. The values were somewhat higher for the 1962 forages (83.9 to 92.8% of total dry matter digested). This could be related to the larger total digestion coefficients obtained for the 1962 forages. Dry matter digestion was larger at 12 hours after feeding than at 6 hours,vdth the exception of trefoil I. Dry matter digestion by the time the ingesta reached the lower large intestine for the 1962 forages was approximately equal to total collection values as would be expected since the samples used to determine dry matter digestibility were essentially feces. Samples for 1961 forages were taken from the entire large intestinal con- tents excluding the cecum and in this case both dry matter 132 oosmausoo H.0HH «n.3m a.mw 3.3m 4 .mm mqmH oHama prnoaamv Hmep :oHpomHHoo Hmqu on» waHLsc wagon :oHumoch astHH how cmpooppooa Ha: T? 40.? mos; «a: H.mm a.mm a.me «.ma a.mm 8.0“ m.Hw m.:: an.am H emmm m.NOH 0.2m m.mm o.mn m.am m.om m.om H.o: «a.mm .H .EHH H.mm o.mm a.mOH n.5m 8.5m a.mm o.mm m.nm mm.om H .mna m.NOH o.mn a.HOH a.Hn m.om m.m: m.mm m.Ha 45.0w H .cHa NmmH Hm»0p a Hmpou a Hmpop m Hagen m coHpomHHoo mmmnoa co (w as NH moxie as‘w co Am as NH co m maxim an m.HmanmmnsH .aqq :HximHe nonHa qmssm squwHo ponHm .wHo nmnHm QADZHezoo mm uamwe 139 and fiber disappearance values from the large intestine were over 110% of total collection values for brome grass II and canary grass II, but close to 100% for alfalfa II and trefoil II (Table 33). The percentage of fiber that was digested in the rumen was similar to that of dry matter digestion. Fiber digestion in the rumen of trefoil as a % total fiber diges- tion appeared higher than that from the other forages for both years. But total digestibility of trefoil fiber was lower than that of other forages (PH<.01). A faster rate of passage with the relatively large intake of trefoil could reduce fiber digestion. However, alfalfa with a similar fast rate of passage had fiber digestion coefficients only slightly less than the grasses. This might indicate a chemical difference between "fiber" from trefoil and that from the other forages. Wet G.I. tract contents as a i of body weight 6 hours after feeding ranged from 17.2% for alfalfa I to 24.1% for canary grass II (Table 34). Sheep fed alfalfa II and brome grass II had approximately the same total wet digesta con- tents while their dry matter consumption was 3.25 and 1.78 lb. respectively. Sheep that consumed canary grass II at the rate of 2.08 lb/day had about the same G.I. tract fill as sheep that received trefoil II at the rate of 3.87 lb/day. Gastrointestinal fill of sheep receiving trefoil I, timothy I and canary grass I was about the same. Wethers receiving alfalfa I had less fill than the above sheep though the 135 cosmduaoo nHam munHH .m>< Nam 0mm awn oomH mmoH H emmm mmmH NmmH nmmH mmmH HH emma omHH QNOH wmmH oan wHHH H .eHe maOH NmOH :aOH mmOH HH oeonm aHHH mmm mmm ommH oomH H .mp9 NmaH oan NmMH mmmH HH .mp9 mmm anH 0mm mOOH new H .aH< omHH mamH amNH m30H HH .aH< Hammgm co .nH 00H\wv poms» Ho :H so Hence DH“ Nam. cm>< an om on Hm as H comm mom on an we HH emma an on Na om mm H .aHe name as am we HH macaw on no on we on H .mnH nmmu an mm mm HH .one me mm mm me an H .eHa nmo am no me HH .aHa mpcmpaoo woman H0 nos Hmpop mo & m mm menopaoo amasa no: wmmm moam .m>4 aHmm “HNOH came comm mmnm H comm «ammOH mmmOH manH nmmOH HH omma mmmm nmmw :HwOH ommm mmwm H .aHB nmwmmw mwmm mmmm mm:m HH oaopm mmom aaom mHmm ooam 02mm H .one mm42Nm0H ammOH ammOH mama HH .mp9 mama mem mean cows ammo H .aHa nwmaaomm HHOOH wmmm came HH .eH: Hamozm eo.pH OOH\wV pawns Ho :H mummmHe no: Hmpoe .m>¢ IIIMJMQIMflI. H.ns w .m>< muwmaom Hmmw momenom Nmmw .Hmpoe on» no R m mm mucopcoo amasm paw mucopcoo nomaa HmaHpmman opummo Hmpoe .dm mqmde 136 .mpaopsoo HmaHpmmusH Hamam mOSHoaH pom mmomm .aopswsmam cam mchoom pwma on» nomzuon Hm>popsH maHp oSp on mammoma new mmw .m>< ow mm mm um Hm H comm am am ow mm HH comm om we as am Nm H .aHe an an on Nm HH meowm mm on mm mm ow H .ohe mm Hm on 35 HH .mp9 we we we we mm H .aHa Na “a mo Hm HH .cHx Nmunopaoo HG mac Hmuop mo & m mm manopsoo Smash mam .msa (Hht: NH H.na e .N>< mowmtoa HomH mommaom mme amazHezoo am manna 137 difference was not significant (P >.05). wet rumen contents made up 65 to 79% of the total G.I. tract contents. Sheep receiving canary grass II had a higher percentage of their total wet G.I. tract contents as rumen contents than sheep receivin alfalfa II (P<:.05). Total dry matter in the G.I. tract appeared to be different for sheep receiving the diffe- rent forage Species though the differences were not signifi- cant (P)~.O5). Animals receiving trefoil II and canary grass 11 had about 1900 g dry matter/cwt in the G.I. tract while those receiving alfalfa II and brome grass II had 1190 and 1043 g dry matter/cwt respectively. Total dry G.I. contents as a 5 of body weight ranged from 3.2% for sheep receiving trefoil II to 2.2% for those receiving alfalfa I. The difference in pH due to time after feeding and for- age species were not significant (Pfi>.05) when the significant (I’<.05) forage species x time interaction mean sum of squares was used for the error term (Table 35). The pH values tended to to be higher 12 hours after feeding than 6 hours postpraudial. There were no significant (P.>.05) differences in moles of acetate or prOpionate per gram of wet rumen digesta. Digesta from sheep fed alfalfa I contained more butyrate (12.0 n moles/g) than did digesta from sheep fed canary grass I (6.8 u moles/g)(P<;.05). Twelve hours after feeding there was less acetate (P<.01), propionate and butyrate (I’<.05) per gram of wet digesta than at 6 hOurs after feeding. 138 “3.0 HH.0 .wse N0.0 00.0 N0.0 00.0 00.0 N:.0 00.0 0000 00.0 0H.0 00.0 0N.0 00.0 Ha.0 No.0 .sHe eN.0 03.0 00.0 00.0 00.0 00.0 0H.0 .009 00.0 Ne.0 05.0 05.0 00.0 0H.0 00.0 .0He .w>¢ .m>4 .pn NH .w>¢ damlw Hence .acuzwsmHm mo maHB pm museusoo smasx 00 mm .00 mamae 139 Digesta from sheep receiving the forages contained an average of 72.4, 18.1 and 9.6 molar % of acetate, propionate, and buty- rate reSpectively. Molar % of acetate and propionate appeared to be similar for all forages and indicated little change with time after slaughter. Digesta from sheep receiving alfalfa I had a larger molar % of butyrate than did sheep receiving canary grass I (P‘<.05, Table 36). Digesta from sheep fed trefoil I contained more total VFA (Cl, + C2 + C3) per gram of digesta than did sheep fed canary grass I (P<:.05, Table 36). Six hours after feeding total VFA content ranged from 92.3 for sheep receiving timothy I to 121.9.n moles/g wet digesta for sheep receiving trefoil I. The above difference was not significant (P;>.05). The change in acetate and propionate content of rumen digesta tended to be larger for the legumes than the grasses when comparing 6 and 12 hours postpraudial digesta (Table 36). 140 was mQH0000 000H 0:» 2003002 H0>n0paH 08H» on 00000m .p0pgwseHm H .cunoo 0.00 I n05.00H 0.N0 0.00 0.00 0.0HH 0.NNH 0.0HH H .0H0 mummec Q0530 p03 w\:o + no + No moHoe oLOHz 00.5 0:.0H .000 N. I 00.0 5.0 0.0 0.0 0.0 0.0 N.0 H 0000 0.N I 000.5 N.0 0.0 0.0 0.0 N.0 0.5 H .aHa m.m I 90m.0H m.0 0.0H 0.0 N.HH 0.0H 5.HH H .009 H.0 I «a.mH 0.0 H.m 0.0 o.nH :.0H a.mH H .0H4 mumvac mossy 903 w\0pmpmpsn mo m0Hoa opon 00.0H 00.0H .m>a N.H I H.0H 0.0H n.0H 5.5H 5.5H 0.0H 0.0H H 000m m.H + :.0H 0.5H H.0H 0.0H 0.0H 0.0H 0.:H H .SHB .0H I 0.0H 0.0H 0.0H 0.HH 0.0N 0.0N 0.0H H .000 0.0 I 0.5H 0.0H 0.5H 0.HH N.0N 5.0H 5.0N H .0H0 0000wH0 20530 003 w\0umaoHQoaa go mmHoa OLOHZ m5.H0 0H.55 .000 H.0H I 0.00 0.00 0.00 0.00 0.00 0.00 0.55 H 0000 H.0 I 0.00 H.00 0.00 2.00 N.00 :.N5 0.00 H .sHe 0.HN I 0.05 H.00 N.N0 0.05 H.50 5.00 0.50 H .009 0.0N I :.H5 H.00 0.50 0.00 0.00 0.00 0.H0 H .0H< mum0wHo 20830 003 m\0pmu000 mo 00Hoa oaon rude: NH 0>II .M>¢ .w>¢ .iwsd . owmwom 11:0 0:0 H0009 H02 NH H0: 0 nouswsmHm mo oEHB 0:» pm mummmHQ noesm mo pampeoo ¢m> .00 mqm¢e 141 H.& 0.0 .w>< 00.5 0.0 5.0 0.0 N.5 0.0 0.0 H 0000 00H.0 0.0 0.0 0.0 N.0 0.0 0.0 H .sHa 000.0 0.0H 0.HH 0.0 N.0 0.0 0.0 H .009 00.HH 0.0H 0.0H 0.0H 0.NH 0.0H 0.HH H .0H0 00000030 R 00Hoz N.0H H.0H .000 0.0N 0.HN 0.5H 0.0N 0.0H 0.HN 0.0H H 0000 H.0H N.0H 5.0H 0.0H 0.0H 0.0H 0.5H H .000 N.5H H.0H 0.5H N.0H 0.0H 0.NN 0.0H H .000 N.5H 0.5H 5.0N 0.0H 0.5H H.0H 0.5H H .0H0 mumomHo E0630 SH mpmnoHQoam & 00Hoz 0.N5 0.N5 .000 N.N5 5.05 0.N5 0.00 5.05 0.H5 0.05 H 0000 0.05 5.05 5.05 0.05 0.05 5.05 0.05 H .0H0 0.05 0.05 0.H5 0.55 0.H5 H.00 0.05 H .000 0.H5 5.H5 0.00 0.05 0.05 0.05 N.05 H .0H0 mum0wH0 :0530 :H 0000000 & 00Hoz M0.00 40.00H .w>¢ 00.00 5.05 0. 0 H.N5 H.00 0.00 N.NOH H 0000 000.00 0.00 0.00 0.00 0.N0 N.00 0.00 H .aHe 00.NHH 5.00H 0.5HH 0.00 0.HNH 0.0NH 0.0HH H .000 0: NH m> 0 dMMd dwbd I0w>< H0009 H00 NH H00 0 QMDZHBZOQ 0M1mqm<9 DISCUSSION Comparative Responses of Sheep When Fed Various Forage Species and Cuttings Although digestibility of forages pgg‘gg has been used extensively as an indicator of their nutritive value little work has been done comparing relationships between the diges- tible energy concentration in some of our common forage Spec- ies,intake and animal performance. Reid gt a;, (230,21“) re- ported little difference in digestibility of forage species and varieties while Minson.gt_al. (179) showed significant differences. In the present investigations reed canary grass (1961) had the largest digestion coefficients of first and third cuttings while trefoil (1961) had the largest digestion coefficient of the second cut forages. There was little varia- tion of digestion coefficients between the 1962 forages but in both first and second cutting forages brome grass tended to have the larger digestion coefficients. Average digestion coefficients for the different forage species combining both years and both cuttings ranged from a low of 60.b% for alfalfa to a high of 62.5% for brome grass. Within a particular year and cutting there were significant differences in forage dig- estibility, but when first and second cuttings for two years were considered there was very little difference in the diges- tion coefficients for the different forage species, harvested on approximately the same calendar date. Thus, factors other 1#2 143 than species may have a dominant effect on digestibility. Average digestion coefficients for first cutting for- ages of 1962 were 2.5 percentage points higher than digestion coefficients for first out 1961 forages which may be related to the fact that the 1961 forages were harvested approximately 17 calendar days later. Alfalfa and brome grass digestion coefficients were increased 5 percentage points by earlier harvesting, but first cutting trefoil, canary grass and brome grass had similar digestion coefficients for both years. Several workers (62,126,230) reported a .5% linear decrease in digestibility of forages with each day that harvesting was delayed. Murdock g; gl. (187) found that decreased dig- estibility of orchard grass with delayed harvesting was not a linear relationship. Data from the present eXperiments would indicate there may be variations due to different for- ages and Species in respect to decreased digestibility with delayed cutting or large year to year variations. Digestion coefficients for 1961 and 1962 forages were greater for first cutting (62.2 and 6b.? respectively) than digestion coefficients for second cutting forages (56.6 and 62.6 reSpectively). These results are in agreement with those of Reid gt El. (230) who reported that early first cut- ting forages were more digestible than second cutting for- ages. Lignin content of the forages studied was negatively 140 correlated with dry matter digestibility as determined by sheep. Forages with the greatest lignin content (the legumes) were the same forages that tended to have smaller dry matter digestion coefficients. Fiber content of the present forages was also negatively related to forage dry matter digestion coefficients as determined by sheep. The above relationships could be an artifact due to the fact that the legumes were con- sumed in larger amounts, thus possibly resulting in lower diges- tion coefficients. Large differences were found in 3Q. gig, consumption of the individual forages and forage species. Consumption of first, second and third cutting trefoil was greater than that of alfalfa for the 1961 forages. The reverse was true for the 1962 forages. Alfalfa and trefoil were consumed in larger amounts than the correSponding three grass hays for both years. Consumption of brome grass was greater than the correSponding canary grass. This was in agreement with work by Fulleman and Burlison (98), Garrigus and Rusk (99) and Blakeslee g; 3;. (30). First cutting 1961 timothy was consumed in amounts slightly less than first cutting canary grass and slightly more than first cutting canary grass for the 1962 forages. Loosli §£.§;, (152) reported cows consumed alfalfa and tre- foil in slightly higher amounts than timothy while Pratt gg, (al, (206) indicated that alfalfa was preferred by cows over timothy when they had a choice. McCall g; gl. (l6u) reported 145 intake of brome grass was lower than other forages studied. No significant differences were found between consump- tion of the different cuttings. Average consumption of both the first and second cuttings of 1961 and 1962 forages was about 2.9 lb. per cwt. Consumption of 1961 third cutting forages was slightly less than the first and second cuttings. Carroll (53) found that milking cows consumed more third cutting alfalfa than first or second cutting. Porter 2; g1. (202,203) reported that there was very little difference in consumption of early bloom first, second or fifth cutting alfalfa. Since growth characteristics of the various cutt- ings change with differing climatic and environmental con- ditions etc. (53,202,203) there is little reason to eXpect similar results when comparing successive crops by different investigators. Forages with high lignin content did not result in decreased forage consumption. In fact, a significant (P‘<.01) positive correlation was found between lignin content of forage and dry matter intake or digestible dry matter intake. Results reported by Stallcup §£_gl. (256) were in direct opposition to these results. However, Stallcup g; _l. (256) were comparing forages with much larger lignin contents than found in forages used in the present study, forages in diffe- rent stages of maturity and only one forage Species. Results of the present study with sheep indicate that intake was not 1&6 necessarily limited because a forage species contained a relatively high concentration of lignin. The positive corre- lation between intake and lignin comes about because the grasses were low in lignin and consumed in smaller amounts than the legumes. These results are not necessarily in opposition to the many findings indicating that intake de- creased, as harvesting was delayed and lignin content increased. Meyer §£_§;, (173) reported that lignin could not be used to predict forage quality when more than one forage species was involved. A positive, though not significant (P,>.O5) correlation was found between intake by sheep and fiber content of the forages which is in Opposition to general beliefs. These data might indicate that forage species had more effect on the gg lip. consumption than fiber content, when the forages were harvested on a similar calendar date. Varying intakes of forage produced resulted in more variation in total energy consumed than did digestible energy concentration. Intake of experimental forages ranged from 3.63 to 2.24 lb/cwt. or a 62% increased in consumption of maximum over minimum forage intake compared to an increase of only 2#.5% for dry matter digestibility. Thus there was 2.5 times more variation from minimum to maximum in forage dry matter intake/cwt than for % digestible dry matter. Other workers (u4,67) have shown that total dry matter intake has a larger effect on animal response than the concentration 147 of digestible energy in the forage. Significant differences were found among in vivo nutri- tive value indices (NVI) for the experimental forages. NVI values for trefoil ranged from 59.4 to 63.5 with an average value of 61.4 which included data from first and second cutt- ings for two consecutive years. Crampton g£_§l, (67) reported an NVI value of 63 for early out trefoil. In the present experiment NVI values for alfalfa harvested in 1961 were always lower than those of the corresponding trefoil. The reverse was found for 1962 forages. Thus over the two years there was little difference in average NVI values for trefoil and alfalfa. NVI values for brome grass and canary grass averaged 14.4 and 19.1 NVI units respectively lower than average alfalfa and trefoil NVI values. Crampton.g§w§;. (67) reported that the NVI value of alfalfa was 13 units below trefoil and that brome grass was 7 units below alfalfa. NVI values for timothy in the present eXperiments were about 9 NVI units higher than those listed by Crampton _e_g §_1_. (67). The present NVI values for canary grass ranged from 35.0 to 49.3 with an average of 42.2 which was slightly less than the average NVI values for timothy and brome grass. Growing wethers were able to make satisfactory growth on first and second cutting alfalfa or trefoil forages (.22 and .24 lb/day respectively) harvested at a relatively early stage or plant maturity in early June. Nethers receiving first cutting 1961 and 1962 brome grass, canary grass or timothy 148 averaged only 0.16, 0.12 and 0.07 lb of body weight gain per day. In contrast, wethers fed second cutting 1961 brome grass or canary grass lost weight, while 1962 second cutting brome grass and canary grass resulted in about 0.1 lb gain per day. The loss of body weight on the 1961 second cut grasses is difficult to explain. The second cut canary grass appeared to be a good hay. The brome grass however, was contaminated with some organic soil. These data indicate a nutritive value index (NVI) of 63 resulted in .25 1b of gain per day in contrast to 0.04 lb of gain per day for an NVI of 40. Starting at a maintenance level (NVI approximately 36) each increase of one NVI unit resulted in 0.009 1b of body weight gain per day while each increase of one dry matter NVI unit resulted in 0.011 lb of body weight gain per day. The above results were determined by regression. Similarily Crampton g2 g1, (67) indicated that a change in one NVI unit resulted in 0.012 lb weight change per day. Relationships among the criteria used to evaluate the forages were examined. Of all the criteria used to evaluate feed value of forages in this and other similar studies, body weight change or animal production has been considered the most important item to measure and to use in calculating relationships. Digestible energy intake per cwt, digestible dry matter intake per cwt and nutritive value indices (NVI) were correlated (P<:.Ol) to body weight change (r = +.72, +.78 and +.84 reSpectively). Crampton E; El. (67) reported that NVI 1H9 were correlated to weight gain (r = +.88 to +.94). The above correlations were determined by using group averages. In the present study if individual animal values are used the correlation coefficient between NVI and body weight gain was much smaller (r = +.59). Body weight change is a very difficult item to measure accurately, especially over short intervals. Weight gain of animals receiving 1962 forages were determined at several different time intervals during the experimental period (appendix Table X). A different weight change is indicated for each time interval used. Also weight gain determined over the different time intervals do not rank the forages in the same order. This was true especially for change in weight for the first 6 days after changing the animals to a new forage. For example wethers receiving timothy I gained .h7 lb per day for the first six days while those receiving alfalfa I gained .27 lb. When weight gain was determined from the sixth to the 28th day, wether receiving timothy I gained .01 lb per day while those receiving alfalfa I gained .28 1b. Change in body fill may have been responsible for the discrepancy of the above results. Throughout this thesis the calculations presented are based on the difference bet- ween weight six days after the wethers were changed to each forage and the end of the experimental period. This period was chosen because it allows some time for body fill to reach a "steady state" and yet the longest possible length of time 150 to measure body weight change. In order to measure small differences in body weight gains longer periods and more ani- mals would be required. Correlations between dry matter intake or digestible dry matter intake and digestible dry matter % were low (r = +.15 and +.20 respectively). These data indicate that diges- tibility of the dry matter was of little value in estimating dry matter intake or digestible dry matter intake of different forage Species and cuttings. Although dry matter intake was correlated with animal gain, the correlation coefficients were larger when digestible dry matter intake or nutritive value indices were used. The latter two factors are a com- bination of dry matter intake and digestible energy concen- tration. Thus although digestible dry matter % was of little value in predicting animal reSponse, when combined with intake data the relationship with animal response was improved compared to using either item alone. Regressions of daily body weight gain on digestible dry matter intake, on digestible energy intake or on $3 1112 nutritive value indices could be used to predict body weight gain with similar accuracy (Table 11). All three regression equations had a standard error of X on Y equal to about .07 lb. The above standard error of .07 lb is 17% of the observed maximum range (-.08 to .3“ 1b/day) found in average weight gains when the experimental forages were fed to growing wethers. Thus the above methods would indicate 151 only large differences in forage nutritive value. Correlation coefficients of nutritive value indices (NVI) with either digestible dry matter intake or digestible energy intake were large (P.05); however, weight gain and dry matter intake were correlated (P‘<.01). The reverse was found with rabbits. Cell wall constituents as determined by Van Soest were negatively (P<.01) related to dry matter diges- tion coefficients for rabbits but seemed to have little relationship to dry matter digestion coefficients determined by sheep. Weight gains by sheep and rabbits receiving the same forages were not significantly related (P:».05). These data support conclusions by Watson and Godden (271) as reported by Richards g§_§;, (218) that rabbits could not be used to predict the nutritive value of a forage for rumi- nants. Dry matter intake, digestible dry matter intake, dry 153 matter nutritive value infices and body weight gains of rah- bits and heifers were positively correlated (P<(.05). The difference in observed response relationship between rabbit if U) and sheep compared to that between rabbit: and heifer very difficult to explain. Dry matter intake, dige estible dry matter intak e and dry matter nutritive value indices of sheep and heifers were correlated (PW<.05). However, weight gains for the two animal species were not significantly related (P) .05). These data indicate a positive relationshi; of energy intake by sheep and heifers when receiving the same forages with no significant (P >.05) relationship between weight gains. Also weight gains of heifers were not significantly related to or these two reasons we ght gains of 51.] their energ intake. heifers in this experiment were probaoly of little value in indicating the nitritive value of the experimental forages. Despite usual precautions and use of a 10 day preliminary period, the weight gains observed for the heifers appear of questionable value. A larger number of heifers with longer growing periods would be necessary to obtain sufficiently accurate weight gain data. However, dry matter intake or dry matter nutritive value indices as determined by the heifers would give an estimate of nutritive value for the experimental forages. Several workers have indicated a relationship between digestion coefficients obtained on sheep and heifers, but there is little work comparing ad lib. intake and weight gains for the two animal species when the same forages were fed. Drv matter intake by sheep ranked trefoil first for each of the three 1961 cuttings, while intake by heifers ranked alfalfa first in each case. These differences were, however, small and not significant (Eg>.05). hith heifers there was little difference in consumption 0 first cutting 1961 forages (2.3 to 2.6 lb/cwt). Intake/cwt of these same forages by sheep ranged from 3.3 lb for trefoil down to 2.4 lb for timot y. The correlation coefficient for dry matter intake, between sheep and heifers, though significant (P‘<.05), indicated that only 325 of variation found in dry matter consumption by heifers could be accounted for in dry matter consumption by sheep. These data indicated that dry matter intake by sheep may not rank forages in the same manner as intake by heifers. Sheep consumed more forage per cwt than did the heifers. However, dry matter intake by sheep was determined from late fall to mid winter, while dry matter intake by h ifers was determined during May when temperatures are war- ur - lp' mer. Heifers consumed 94.8 g dry matter per Wt-kg'73 which was larger than 83.6 g for rabbits and this in turn was larger than 70.3 g for sheep. Relative intrke (RI) of the forages was greater for heifers than for sheep with RI for rabbits being intermediate All HI values for heifers and rabbits were determined by using Crampton's et al. (67) BI formula for sheep, i.e., 100 x g daily forag DM intake _L 80 (iii-t 0kg.75) Crampton and coworkers have suggested using a value of 140 in place of so in the above formula when dairy cows are used to determine forage nutritive value indices. The ques- tion arises as to what constant to use for heifers weighing 500 lb or any other intermediate weight. If 3 lb dry matter intake/cwt is a standard intake, researchers might better use this as a relative standard intake rather than intake per Wt. '75 corrected by a constant to equal 3 lb dry matter in- take/cwt. The only reason for usinr relative intake was to compare dry matter intakes from trial to trial on a standard basis per unit metabolic size. If this is the intention, then all workers will have to use the same standard intake and express their individual values as a a of that standard. The necessity to use a different constant for each particular weight increment makes this cumbersome and time consuming, wherefs exoressing observed intake (lb/cwt) as a fi of expec- ted intake (3 lb/cwt) would aleviate all this mathematical l Animal Performance ”‘1 In Yitro Fermentation v In the present study the disappearance of forage ory 156 \I) matter was measured by an in vitro fermentation method d s- cribed by Bowden and Church (bl) with some modifications. Bowden and Church (bl) concluded that with their in vitro fermentation method, variation between replicates were smal- ler when disappearance of dry matter rather than cellulose disappearance was measured. The literature as a whole indi- O cates similar standard errors for i vitr cellulose and dry matter disappearance coeff cients of fo "5 ages. Bowden and Church (#1) found dry matter disappearance of an alfalfa standard in 13 trials had a standard deviation of 1.9 and a coefficient of variation of 3.3%. In the present study duplicate disappearance values of dry matter for the 1962 standard alfalfa determined on 6 different days (or trials) resulted in a standard deviation of 2.3 and a coefficient of variation of 5.1 (Appendix Table XXIV). Bowden and Church (41) summarized data from several workers and listed standard deviation of i 9.3 to 1.9 for in vitro cellulose digestion of tandard errors and coefficients of variation in Le forages. the present study ranged from .5 to 1.4 and 2.8 to l0.7£ res- pectively (Appendix Table XXIII) for six hour disappearance of dry matter for the 1962 forages. Similar standard errors and coefficients of variation for 36 hour disappearance of dry matter ranged from .9 to 1.8 and 2.5 to 6.u respectively. Coefficients of variation for dry matter disappearance of canary grass I and II tended to be higher than the oth r for- 157 ages at the six hour fermentation interval. This difference was not apparent at other fermentation intervals. For com- parison, the standard error of in viva digestion of dry matter for the 1962 forages by four sheep ranged from .6 to 1.5. I vitro dry matter disappearance values for the 1961 forages ~— had comparatively large standard errors and coefficients of variation (Appendix Table XXIII). The large standard errors were thought to be caused by variation in non-filterable dry matter from the rumen inoculum placed in each fermentation flask. The rumen inoculum was not settled before use in the 1951 forage fermentation trials. Allowing the strained rumen fluid to settle and removing the particulate matter reduced the non-filterable dry matter by a factor of 4.5 (Table 27). Also less rumen inoculum (24 vs. 60 ml) was used to digest the 1962 forages. The net result was a reduc- tion of the variation between replicates by over half. Reduc- tion in the amount of rumen inoculum and settling had little if any effect on the amount of dry matter that disappeared during fermentation (Tables 25 and 26) which is in agreement with work by Church and Peterson (58). The thirty-six hour interval of fermentation resulted in the highest correlation (r = .72) with lgnglg digestible dry matter % (Table 19). Bowden and Church (#2) and Tilley et a; (25h) used 48 hour in vitro dry matter disappearance of dry matter to correlate with fi 12 vivo digestibility while 158 Donefer et al.(82) used 24 hour cellulose digestion. John- on et 3;. (130) used 12 hour i itro cellulose digestion L) CT ’3 O as an indicator of in i digestibility. These differences 3 I .r F.) may be a result 0 the different i vitr systems comparing ‘- o—.. or coinciding with in vivo phenomenon at different times. Bowden and Church (42) summarizes the literature for corre- lations between ;_.1;tro digestibility and la vivo dig-stibi- lity with r's ranging from .50 to .98. The above data would indicate that forages can be ranked according to in vivo diges- tibility by Ag vitro digestibility determinators only when there is a large range of values. Of much more significance than digestibility of a for- age is the amount that will be consumed. Daily intake/cwt of H.) orages was correlated to 6 hour in vitro dry matter disappear— SD nce from 1962 forages (r = +.94), 1961 forages (r= +.54)and all forages (r = +.74). The lower correlations found between _13 131g and ;g vitro data for the 1961 crop in comparison to data for the 1962 crOp may be due to the very large variations in dry matter disappearance for replicates of the l9ol crOp. Donefer et a . (82) reported that 12 hour Ag vitgg cellulose digestion was correlated (r = .83) with relative intake of forages. Johnson et g;. (130) also found that relative intake was correlated to 12 hour in vitro cellulose digestion (r=.87) when only grasses were considered. The correlation coefficient drOpped to .69 when several alfalfa hays were included. 159 Disappearance of dry matter in the early portion of the in vitro fermentation (6 hr with the present study) may give values that indicate rate of forage degradation in the rumen and dry matter intake. Forages that were consumed in lesser amounts such as brome grass and canary grass in comparison to alfalfa and trefoil seem to have a slower rate of breakdown in the early portion of the fermentation period. Fermentation curves (Fig. 7 and 8) show the "lag" of dry matter disappearance of brome grass and canary grass and are l. on similar to those of Donefer gg al. (82) and Hershberger gt (116). As the fermentation continues with time the dry matter disappearance curves cross over to rank the forages accord- to i vivo digestibility. This crossing over phenomenon ing was absent when four maturity stages of timothy were compared (48). However, there were differences in the lag period that were related to intake and digestibility of the forages. In the later case, digestibility of the forages would be posi- tively related to intake whereas in the former case with crossing of dry matter disappearance curves there may be little relation between digestibility and ad lib. dry matter intake. in 31233 nutritive value index (NVI) (6 x 36 hr in vitro DM disappearance) values did not give a higher corre- lation with i vivo NVI than 6 hour dry matter disappearance values. Similar results were indicated by Johnson §£.§l. (130) p O ‘ (3 and Donefer et 1. (82). Digestible dry matter intake, dig- estible energy intake and dry matter th values were all highly correlated to 0 hour in vitro dry matter disappearance (r = +.85, .90, .59 respectively). Regression equations were calculated for the above relationships (Table 20). Daily digestible dry matter intake/cwt and digestible energy intake/ cwt when estimated by 6 hour 13 vitro dry matter digestion had standard errors of estimate equal to .15 and .lu lb res- pectively. The standard error of estimates of nutritive ti) tt (D value index from 6 hour in itro dry m r disappearance was 4.0 compared to 5.5 from work by Donefer et al. (81). Although the lepe of the regression (1.6 vs 1.3) is similar to that of Donefer _p . (El) the Y intercept is very different (7.0 hi i 5 VS -603) o *5 difference may be due to differences in dry matter and cellulose disappearance or the fermentation system used. The fairly large standard errors of estimate indicate that only rather large differences in forage nutritive value will be indicated by this laboratory method of evaluating forages. The six hour 13 vitro dry matter disappearance was correlated to weight gain (r = +.7j). Other workers have failed to give any relation between their 33 13§3_ digestion values and body weight gain. The standard error of estimat- was .07 for weight gain using 6 hour dry matter disappearance . With this large an error only forages that resulted in large differences in body weight gain could be evaluated by the in: 0\ FJ above method. Slaughter Trials Slaughter trials were conducted to determine if the differences in gd lip. consumption by sheep of the pure stand forages could be explained by rumen fill. Blaxter gt gl.(34) suggested that sheep would eat forage until a constant fill was reached. Crampton gp‘gl. (67) suggested that hunger reoccurred when the rumen "load" or fill was reduced to a cer- tain level and then ruminants would eat until some upper limit of fill was reached. Freer and Campling (96) concluded that dairy animals would consume roughage until the rumen reached a maximum fill or with poorer quality forages, to a level that would result in a certain maximum fill just before the next feeding. Data from the present experiment indicated that the relation between rumen fil’ and EM consump- tion is complex and that other controlling factors must play a role in regulating forage intake. Six hours after feeding or midway between feedings, sheep receiving canary grass, though consumed in less quan- tities than some of the other forages, had a high rumen fill. There is some indication that rumen fill might have been a factor in limiting intake of canary grass. Wet or dry rumen contents 6 hours after feeding were not significantly related to intake (P;».05). There was how- 162 ever, a positive correlation (r = +.7é) between dry matter intake and rumen dry matter fill 12 hours after feeding or J 5‘ CT FL. CT just previous to feeding. These findings mig ndica e rumen dry matter fill 12 hours after feeding is a result of the amount consumed. This relation, however, is based on only four forages each fed to 3 sheep. Average dry matter intake (lb/cwt) of the experimen al forages during the growth trials and the slaughter trials forages tended (D were different (Tables 6, 7 and 28). Th to be ranked in the same order but the actual dry matter intake/cwt was different in some cases. This indicates the difficulty in repeating intake from trial to trial but the ranking appears repeatable. Wet G.I. tract contents six hours after feeding varied from 17 to 2U£ of the body weight. Wet rumen contents as a . percent of body weight'varied from 11 to 18%. Waldo et al. (265) reported that wet rumen contents of cows receiving silage or hay a; lib. were 13.4% and 15.4% reSpectively which is in agreement with 12 to 13% found by Thomas E2 al. (251), and somewhat lower than found in the present experi- ments with sheep. Rumen dry matter content as a percent of body weight ranged from 3.2% for sheep receiving trefoil II to 2.2% for those receiving alfalfa I. This compares with a value of 2.2% reported by Waldo et al. (265) for cows receiving hay 163 . and to values of 1.7 and l.ha reported by Thomas ,\ r) [.1 H (V I (251)for cows fed hay and silage ad lib. respectively. _M (D ('9' (1‘ F4 0 Average dry matter content in the rumen as a percent of the total G.I. tract content varied from 72.#% for alfalfa II to 83.8% for canary grass I. There tended to be a larger proportion of dry G.I. tract contents in the rumen of sheep receiving canary grass compared to the rumen of sheep receiv- ing the other forages. This might indicate a slow diges- tion rate in the rumen of the steep receiving canary grass which is supported by the slow lZ‘hour in vitro dry matter disappearance of canary grass. Thus rumen fill could be limiting intake of canary grass. Trefoil was consumed in large quanties and had high rumen fill in which case rumen fill may have prevented a higher intake. However the positive correlation between intake and ruman fill 12 hours after feed- ing also may indicate that this fill is a result of intake. The amount of lignin and fiber in the rumen appeared to “e a result of the amount consumed. The legumes, containing (1' greater quantities of lignin, were consumed in larger amounts than the grasses, which were lower in lignin content. With the specific forages studied, lignin content of the forages or total intake of fiber and lignin did not appear to limi consumption. A positive correlation was found between dry matter intake and lignin content of the forageS. This was in disagreement with work by Stallcup 93 al. (238). In many cases the negative correlation between intake and lignin content reported in the literature are confouned with a dif- ference in harvest date or stage of plant maturity. A positive correlation for all forages was found between dry matter intake and % dry matter in the rumen con- .1 tents. Thomas §£_a.. (251) found similar results. This would '— irdicate that the digesta level in the rumen does not change directly with increased dry matter intake. Rumen retention time was determined DM in’rumenmm ) Daily LN intake (R: to obtain some measure of how long the ingested forage stayed in the rumen or ingesta rate of passage. Retention time of the legumes was less than that of the grasses. The differences in passage rate may have been due, however, to increased in- take. Cause and effect are difficult to separate in the above relationship. Paloheimo and Nakela (19?,193,l9h) found a curvelinear relation between dry matter intake and rumen retention time. Thomas _2 al. (251) found similar results. In both cases the relationship between retention time and intake was nearly linear from 1 to 2.5 lb forage dry matter intake/cwt. w ldo et al. (265) reported that rumen retention time 9; of drv matter was 1.07 days for cows receiving silage or hay 9‘ f“ 'r-" P h t. which increased to 1.4 days when intake of both was reduced to a maintenance level. Fiber and lignin retention time decreased as intake of dry matter, fiber or lignin increased. This has to be true to a certain extent after a steady state is reached. For example dry matter is coming into the rumen and an equi- V81€it amount has to leave the rumen each day or the rumen would become full of dry matter. However, this does not necessitate that a given food "particle" has to pass through the rumen in 24 hours, but that an equivalent amount will be passed which may include some of the previous day's intake where retention time is greater than one. Where it is less than one the average food "particle" will pass on in les' than 24 hours. The above relations probably indicate that with ad lib. forage intake, rumen retention time of dry matter, fiber or lignin was most affected by level of dry matter in- tedie. humen retention time of lignin was longer than that of fiber and dry matter. The retention time of fiber tended to be longer than that of dry matter. Paloheimo and Makela (194) reported lignin reteition time measured by the method used in the present study as 1.7 times that of dry matter. The retention time of lignin from 1961 and 1962 forages in the present experiment was 1.7 and 2.0 respectively, times that of the dry matter. Dry matter digested in the rumen amounted to 67 to 93% of the total dry matter digestion that occurred. Rumen dry F J (7“ C\ ',_1 i (1* matter and fiber digestibi y from the 1962 forages was higher than that from the 1961 forages. The difference might be explained by the fact that total dry matter diges- tibility was larger for the 1962 forages. Balch (14) repor- ted that 26 to 62% of the total dry matter digestion cocurred in the rumen. The higher digestion coefficients in the rumen were from cows that were receiving some concentrate and the lower from an all roughage diet. Paloheimo and Makela (193) reported that 76 to 99% of the non K-free, non-lignin organic matter was digested in the rum n. The concentration (pm/g) of acetate, prOpionate and butyrate in rumen digesta was greater at six hours post- prandial than 12 hours postprandial, however, there was no difference in molar percent of the VFA at the two time inter- vals. The amount of butyrate and the molar percent of butyrate in the wether's rumen digesta were larger when fed alfalfa or trefoil, than when fed the grasses. Also the decrease in concentration of acetate and prOpionate from 6 to 12 hours after feeding tended to be greater for the legumes. This might indicate a different type of fermentation or a more rapid fermentation rate of the legumes with slower absorption of butyrate than acetate or probionate. Total VFA concentra- tions (92.3 to 116.9 umoles/g rumen digesta) were normal for an all roughage ration as were molar % of acetate, prepionate and butyrate. Pure stands of alfalfa, birdsfoot trefoil brome grass ’ D reed canary grass and timothy were harvested simultaneously in 1961 and 1962. First, second and third cuttirgs were har- vested in 1961 while only first and second cuttings were (1 available for the 1962 crop and only firs cutting timothy was available both years. Fiber content of the forages ranged from 28 to not while the legumes contained up to 2 - 3 times more lignin than did the grasses harvested at the same time. ' A positive correlation was found between lignin content of the forages and dry matter intake/cwt. A significant nega- tive correlation was found between lignin or fiber content of the forages and digestible dry matter %. Intake by sheep and heifers was negatively related to cell wall constituents while intake by rabbits did not appear to be so affected. Digestibility of the dry matter by sheep was not affected by cell wall constituents while digestibility of dry matter by rabbits was decreased. Growing wethers were used to measure nutritive value of the forages in terms of animal performance. Dry matter intake by wethers ranked the 1961 forages in the order of birdsfoot trefoil, alfalfa, brome grass and reed canary grass. A similar pattern was shown for the 1962 forages except that alfalfa ranked ahead of birdsfoot trefoil. There was little difference in dry matter intake of first and second cut for- ages. Some differences were found in dry matter digestibility 167 of srecific forage but when forages of all cuttints and both years were considered there was no difference in dry matter digestion coefficients for the different forage Species Digestible dry matter intake/cwt and nutritive value indices (3J1) followed a trend simi ar to that of dry matter inta e. In most cases, NVI values ranked the two legumes at the tOp followed by brome grass and then reed canary grass. Weight gain was positively correlated to dry matter intake/cwt, digestible dry matter intake/cwt, dry matter nutritive value indi ces an nutritive value indices. Ligestibility of dry matter was not related to intake cwt or weight gain. However, the product of dry matter digestibility and dry matter intake re ulted in a larger correlation coefficient with weight gain than did either individually. Regression equations of nutritive value index, dry matter nutritive value index and di estible dry matter intake on weight pain were about equal in precision of predicting weight gain as shown by similar correlation coefficients and stan- dard errors of es tin' ate. The Standard errors of estimate (about .07 lb), however, were such tlat only la rge differ- ences in forage nutritive value could be differentiated. brv maiter in. ake, digestible dry matter intake, % V m tible dry matter and dr v matter nutritive value indices 0 dige as determined by sheep were not related to the sam e values as determined by rabbits. Dry matter intake, digestible dry intake and dry matter nutritive value indices of rabbits and sheep were positively related to similar values deter- mined by heifers. Weight gains of sheep and rabbits were not significantly (P>'.05) related. Weight gains by rab- ( & bits appeared to be affected more by dry matter digestibility of the forages then dry matter intake whereas the reverse was true with sheep. Artificial rumens were used to measure dry matter dis- appearance of the different forages at Several time intevVa‘s. Initial in itro dry matter disapgearance was slower for the fl.“ arpearance val- U) grasses than for the legumes. Dry matter di ues as determined by 6 hour fermentation periods were corre- lated with dry matter intake, digestible dry matter intake, dry matter nutritive value index, nutritive value index and body weight gains while dry matter disappe'rance at 36 hours was correlated to in vivo digestion coefficien s. Correla- H lation coeff cients between weight gain and i vitro dry atter disaprearance were larger when 6 hour rather than 6 3 hour x 36 “our (1. gitro NVI) dry matter disappearance values were used and the standard error of estimate for the regress- ion equation was smaller. Six hour in vitro dry matt r dis- n“-earance as determined by 6 hour fermentation periods was 9'1 r effective in predicting the nutritive values of forages when there were large differences in nutritive value. aerimental forages were slaughtered v .‘L >< wethers receivin e 0‘? and their rune; cent;nts examined to asc=rtain the relation- A cf (2‘ r :3 ’3 $2. a (D :5 ships be contents of dry matter fiber or lignin and intake. Rumen digesta from sheep receiving the legumes contained a higher percentage of dry matter, fiber and lig- nin than those receiving bro ne trass or reed canary grass. nificant positive relationship w found between dry matter intake a;qd p dry matter in the rumen. Sh neep consumed the reed canary grass in smaller amounts than some of the other forages but their rumen contained the largest amounts of wet ar d dry rumen material 6 hours after feeding. The rumens of sheep fed birdsfoot trefoil which was consumed in *arrer quantities than some of the other for ra;es also con- FJ (V tained relatively large amounts of dry matter in the rumen. L): The relation between amount of dry matter in the rumen and ligitum intake appeared complex and ind_ cated there probaoly wer other factors playing a role in controlling ad LkéilL- ir take. There was some indication that amount of dry matter in the rumen was a limiting factor in the consumption of reed canary «w J ;s. with the specific forages studied, lignin content of (P 9L) w th (T) forages or total intake of fiber and lignin did not appear to limit cons umlztion. Rumen content of fiber and lign n was positively related to intake of fiber and lignin and did not appear to exert a limiting effect on intake. Bate ‘f gassaue was measured in terms of rumen retention time. Rumen retention time of dry matter was about six tenths 171 0 (N r‘ #4 ‘\— ~ - u a r ‘ ‘ q hevw of a day ior the legumes and one day for the grasses. As 5 dry matter, fiber and lignin intake increased,retention Q1 time of each constituent ecreased. The differences in gass- ‘y be due to differences in dry matter intai:e or fa ‘e Pat 5 m 9.) m differences in intake may be limited by passage rate. rur- ther studies will be necessary to determine which was the cause or effect. Rumen retention time of liynin was greater than that which was gr: eater than that of dry matter. Thus, 9 (‘4‘ .‘ Oi i;3¢.‘I‘, some portions of the dry matter were pa sing through the rumen faster th in fiber and lignin. Dry mitter dige; ted in the rumen amounted to 67 to 93; of the total dry mstter digestion in the entire G.I. trac t. humen dry matter dige “ tion coefficients for the igez foraces were larger and made Up a larger portion of the total dry matter digestion coefficients than those for the 1961 for- ages which had lower tOtal dry matter digestion coe fficiente. The rr oportion of fiber digested in the rumen compared to the #4 entire G.I. tract was similar to that of dry matte . Rumen digesta from sheep receiving birdstOt tre oil I contained a higher concentration of total VFA than did wet hers receiving reed canary grass I. Butyrate concentra- tion was greater in the rumens of sheep receiving legumes rather than the grasses while ther were no significant diffe- rences in ac e Hat or prOpionate concentrations (l) ( ) \n (b) (7) Alexander bits , 3‘ '- \ Ll LlfhhA al he.t earch Servic 5h Quality Ha". ABS F., and A.K. Launch. SPLC.J. ‘ wgzzrat‘ive gees bv catt 1e a A? ‘ M., v " Spee . 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Ncuilliar“, A.D. he-entrant duodenal fistuTa tect.i3ues appli cation to the study of digestion and gassa;:e in the oov ine alinezitary tract. Ph.E. Th331€.'(Wr.Q a1 State an.lersitv. 19o1. (17¢) (171) (175) (175) (177) (178) (179) (180) (181) T <‘ . w - "’ ' f r ‘ 'V n , , \ " heiéb, E.n., and h... LOHVfircfi. -—‘ A 3 * V "' q I 1‘ § ~ ' (rent KLch 0: may in the 1 of dairy cow. u. Dairy 5., and E.T. Cor:verse. The alpa hay as the ::ole roughaLe T comoinec. J. Dairy 501., Heigs, on L.h. Ioult on, and v of timothy hay "s at“ An j. FT} 211 ‘ C‘. .30 ., T ‘ a ‘ T u OILQCW ’ 21nd u .‘ I - I iv ‘L -“ ‘ .- \ ity, d had atihé v .- ‘ " 1 -. ing on alialfa haJ Meyer, J.%., Effect of V field-curring an as measured by l 1900. 1. H71. daulif" nninal do 19: 253. ., do u. o, Nutritional value of subtropica pasture 3 under Australian conditions. i " m1 ' 0.; hth Internatiozial Gr:1s T T h " *— CELTWOIJ, . L,- . Mai CON 1 H . palataOiiity of calf t 9,3 J CL. oils on the 801., #1: 1 Miller, of Anise J. Dairy '; T w .‘J’ . , h‘ 0\ (X) o H ? E‘; 715(3n, 9...} . , md a. supply of ure ci. . f ., Effect of a continuo‘s of low quality forage s Pig ien. .L W W o 'J 0 0n Uti' J. Animal ' , 20: 962. 1951 Mir son, 3.7. Methods of expresszinv foray va ue Theno from Animal hesearch Inst Einson, L. J., H.F. Iiaym ind, and v.2.narr 2. studies in the digestioility of herbage. VIII. The digesti- bility of 537 cockszOt, 823 hyegra ss, a.d "an Eye- grass. J. Erit. Grassland 800., 15: 174. thO. 1' H84 - H ‘1 (N ,, ‘- '.‘_‘ I" " Einson, ~.r. HaJmona, aha c.z. and vari T 1' 3"." o , r i tibility of grass sp3cies eti s. Proccedings of tr e E1 shth Interne ti anal ‘rassland Congress. P.470. 1960. Mitchell, H.H., T.S. iiamilto on, 3 rate determines speed 01' passage. Ill. S-' 1:01—47. 192;. Moore, L.A., J.W. Thomas , and J.C. Symes. The accegta- , M»i ity of gganS/l gime silage oy otiry com. Proc. Eighth InC“P“”t‘OU11 Grzsgland Congres., ;.70i. 1900 (136) (137) A F’ (j) (1’) v (191) W h \ lie Hoo:re, L.A., and 0.8. Winter. Rate of patsage of inert mater ais through the oi:.ntiv‘ trac ct of tne bovine J. Lairy $01., 17: 297. 193A. Morris, J.G. Luienciard J. AL'cri .Sci., 15: 161. 1955i. Cited by Ealch (ll). ‘1' Morris, u.G. aueaisiand J. Agric.3oi., 15: 181, 195A. Cited by Balch (12). Mott, 0.0.. h.?. BarneS, CGW 113 HS” P. 0- EonovaA, I‘.TV.’. Pac,{ett, N.F. Plumlee, arld H.:J. Lag; hC—D. Tne develOpment and application of 1300 atory methods for determining forage quality. uC-ou Progress hurdtck, E.h., A.S. Hodgson, and J.R. Harrie. Bela— tionship: of data of cutti n3 stage of Taturit‘ and digestibility of orch? 1rd grass. J. Dairy Sci., Tech.hote. 4b: 19L}. 1961. r' ..A. The quality factor in feeding stuffs. u. ALr.Sci., 2': 185. 1933. ; J.A., H.E. Ellenberger, O.M . Camourn, and C H. Jones. Digestibility of alfalia, timothy and e L s silages and as aye. ‘Jerm ont Azm ic . .bu l]. .UBO. 193” Kordfeldt, 8., I. TwanaLu, K. Korita L. A. Heuke, and A.K.S. Tom. Irfluence of crude f Cer in the ration Iticiency of feed utilization by dairy cows. J. dairy 301.. 33: #73. 1950. 'Lelt, 6.2., W.A. King, W.C. Cook, and S.L Moore. Efxect of physical state of coastal B rmuda grass 'hay o;c yifibi :e through di gestive tract of dairy hFJife eAE‘). J. Daj-rJ £101., 14’6. 3:. 19b}. Palonein mo, L., and A. Rakela. Further stufies on the retention time of food in the diLestive tract of cows. Acta ALrelia Eennica, 9U.2: l. 1959. Paloheimo, L., A. Makela, and E. . Salo. Some quan- titative data on the role of tne ruminant proven- triculi in the digestion and atsor ption of nitrogen- Ire e orLanic material. J.o31.ALric.;ocof Finland, 27:70. 19)). L‘ f—J ’4 1X) 1.: (I) \O ‘r fl ‘ - r‘ ‘ ‘ \..(\" r -I (v -. “(~'<'~c‘ 'v~ PdLonulmo, L. c.nd n. hufield. Tne FatE of pahoagc f Iood in the digestive ract of ruminants. J.Sci. . . .x . v ,. q ,. . .1 ' ~::r~ né‘_rl0.k:'\l'd. Oi F|,1.nlrllid Cr . 16;". l9JL-. T 77 ‘v 1 h 5. ‘. -‘ 1 N-.. o— ! ‘ ‘I‘f‘YTT U :1.’ alfld 5%.“. uC’10'tt. fi’iEJDLlI‘e C11: (1133. A, llni LLT. C ect of lignin content and of stage of matu Arity dry ciover forage on the urinar ry excretion aromatic acids by sheep. Sci .Ag:., 2?: 39. 19~9. Pazu 7‘\ Phillips, 8.3., R.E. Hungate, A. NacGregor, and L.?. hung ate . Experiments of rumen reterltion time, T: mentation rate and dry matter d: "e‘tioi‘itj in Zebu and EurOpean-type cattle on grass hay ration. J. Agric. Sci. 5b: 917. 1950. Phillips, T.G., J.T. Bull. 1 "‘ D , TEEUE. onenical composit on of isome forage ‘1 v -* 1 I i lant ncnngrity. rygronomy Phil1ipson, T.C., and E.E. Laughlin. Comtrosi tion and ngestiole ene‘gy of Gays fed to cattle. Journ. “{Ir‘oueso, 17d: 3:70 19490 L- -ir relations with other cia 104 PS Picxe tt, H.C. Vor- e a in bromegrars. :rom mus inerm s Leyess. Agronomy J., 1 oil ty of crude protein and carotene C e influence of gassage of feed ct of rum inants. d bYL 001111“? ff :3" 7 A level 0 t. Naataloust. Aikak., 2 (169) . Pope, A.L., C.W. Cook, W.E. Linus son, U.S. Garrigus and w.C. heir. Nutrient rezuirements of domes tic ani- mals. V. hutrient re uirements of sheep. National Research Counci- Publication fiSOh, p. 11. 1957. .-\ . f‘ v W1 ‘ \ 1 C‘ J." 9 4 r- '0- Porter, n.1., and S.n. ‘ aggfi A compariuon o1 11reu, r‘ I ~ '3: fi ‘ v‘ 1 pl ‘ "‘ " ‘ 'r ‘ occonc, -Ld fiitn outtints of a1.alfa hay. n1r1c. L “t 'ew Mex ico State University. :u11. 4.. . r ‘1 r 7‘ 31:1 " L. C : r ‘ . ‘ N , , L POPUEF, d.‘t.’ ‘1‘". A'lJ-L-L?P, 5.24.0 U.“ . DKELEEK . bOZCIOE/i- ‘ r's -. . a ‘ “ ‘ “ ~'— : . a v 1 o" “ tion 01 LJrMAz, seCcno.cin1 iiftn 0“,:1IQ.:«31 a1.a1- f‘ \ w ‘M +- .. ' 7‘ ' . C l ‘ J W“ 7(_"."‘. 1a Ior milfi proaiction. u.-31r. cc;., e3::cc. L;oc. (2 05) (203) ( 09) p . 1 \ .v r'\ 7“\ (21h) Poulton L..., n.C. H&V€R, 5.3. Foss, and T.£. Nellin. Comxxrlbon of the result“ of Severe. in vitro for- a,e evaluation tJChn1LuLt with in vivo values. J. Da‘rv 301., Ht: 147. 1993. Pratt, prefer hesearch 33 (:4 ' ’\. «'9 v A.U., JQVU. I“. '1 y,, -r‘ - .1 ELK/(11160 3. "\Je .‘ t 6 Pratton, 5.1., and L the liLLin " c Er&319b. J. T Procter, F. and R.C Wright. ‘ ‘ \ fl :‘ LLIL‘]. b.5—Q concept of stro-intestina1 L» i‘ raqt‘ Cl 7 & «Q U J Knocg. Dcirv heifers Ohio farm and ' :1 ' t O :4 (D :0 chrfiqges in scnne Koritarx. sonal content of 1"“ l9&2 O L‘(' . C' o QEE’X Bulk in animal feeding. 1 (Nix) 0. AL 1c.o31 39:. 1 1 . , ' ‘ ‘ / V7 ‘\ \ 1' fl \ 41 ='.‘ C ‘ ,‘ Y ?' ‘ qdlCKE, u.v., b.b. Lentlcy, L.u. ccott, and A.». onon. ~. 1 ~, 1- -. -,. ~ . - - r ' ~ ‘ +- C611u-OLc G113oClOfl 1n VLtro 1s a Teunure o: the ‘ /- - ‘y\ -‘ v “ pm ‘ - - '\1 '3 \ 4‘ “ . V, \‘b C15Cntiu11itj o1 1orage oe1lu10t- 1n ru"_nun.:. 1' , ~,~1 U ‘3 ' "w '1 ‘K U . tum-1mm; 5.201., +5.4: L’75. J—( ’9. I ‘W P‘" V.‘ 7‘- -\ I‘ A_ .. "w‘s ( ¢uig1e., J.r. 1he rrle of Bar c11e12tive tract in “H fi I‘ ‘ ',. -.v r- "\ r.. ‘ re1u1at1ra LG: linge; :tlon of :ood. Annalo. of the T. '\ ' " .\ ' ‘ R f“ 7 / r 1' new fork hoaie.y of £311n1e3-J: o. 193,. r - 1 1 1 ~ r .- '7- ' 4. - ‘ 71 “(a {tvb’ 1‘..1.. ’ [1.1... ie L'l, {1-51,} L.u‘. POTUE—rfie-LCI. k pr" ,‘v’ w. p 7». . 1 , ~ ,“ +* . ‘-' " ‘v,l" FC‘ 5‘ . 1ctdluL vaLue 1or 111k tro1Acc1on o: hcgo cut at l l . ' A(~v‘- 4 if P- '»\.P \k C.“- ‘Ir(;$r1ik)‘l L: dsA-CLK‘I . V‘J’C‘Q u ‘Jbr‘gin- 1 ‘51”10. 331,1; .Uu8~. V , .. ‘1 ‘/ r‘ current nepor. 35. .9o.. r. ' (‘1 ‘ T‘ r‘ m ' 7‘ r‘ {Icim-aicd‘i, (1.1)., (11d 1.11.. £310.) 0 V —. ‘- ' ,1. . ‘ 1or HIEQICCJAE foraée 0 Lo '3. ‘0’:- naymonq, “.r., 13“}. Kinson,c illty of 14: 75 in the cléestio Grassland r1 4-. n 3.10". ’ Held, J.T., W.K. Kennedy, K 0 v ' .' ‘IY. _‘ “ _‘. V" r b.a, .r.imteréem‘, eurxi h.r (\ *— r' ' , " r , "‘, ‘ ‘ ‘- ‘ “vase CHURiCai comro:1U1 ies :1pon the nn?ritjv; Lairy $01., #2: fit 7. 195 Vitro techniqu T ‘ ‘ '1 ‘ .~~. : h- . .PuI‘K ’ u . - . S.-1ZC[{, . hurphj. affect of growth ,. .1 _‘ . ' . ,.r-\ .1 .\ ‘V‘ ’4 01”., 4.110 111.. :1 111:.- L prey: I"- : 0 q I" \ In K‘ v v 11111. c: 1 cr.~..-.e- . 1, . 1 1n '0 v (2“- r‘ ., \ . 'rfil (a ' " .1 C100 ,q H v onchi v x J. O \L I. Y. o 0 TL «D o .14. h e xi. \Iz ,CQ 1““ ‘L a. #A Y!) in ‘YIC L5,; bro I . .L 7‘ oh 0 a. .L r "‘ Li ixl 1} AV .1-" 0 at. C/ I,” .:_‘ m 0 .IA 1“ t O O .12 ’..\J W. a; nu t O- 1 1. my... GM 13‘ .t "L <5 I, I O 1. P13 0 I Y A‘ . l . ‘ . \fi '3 in l .mA.L.A4 0 .1 ll. 0» ‘4‘. Vb .— U of ’ ‘ .11u1 fi.p~o.‘ t 2* mo kl in J .L. . ‘. cl; an. . .1; d; Irv OJ 1‘) \J. (V "J n O: crude fil-’ v‘A . n vJ a . 1 11 w. nv1c ,1 .) nx1 “\4 fifuJ m1 3. o 4.“ E u o w. J C «Q , «1 AL 7; l h {L \1 Y1 :L P .1..— V. 1 Fl. 0» .W 9 O I: f.\ O ¢u 944 f. r O.\ T. ’ 0 PL TH). /4:\ O In PM “.1 _U D L 0.1 :; 4Q n ma AZ ‘hoxyl, tor Cr? 0 ‘ A. .3 w .cdgna*< Vl" v ‘3‘ :flxt 33r~ 74v (.,h.1u. I W‘f‘ . I h 0“. Pk . {A V.‘ C a .\.- I‘“ Y’ V L ?d L 3 Y .111 ,-. ,. 1pc.) CUE." " Li I l . and U.V.J.’ {V \L 1'; t o u. L _U n.“ .l v 1 ‘00 la... (b I I L _ 76. _ w F. u A v 1 tr. \. x. . PM Y a C “1 0V «or, 1 'C 7.. . . \t LIL ..,.n .U 'l 0’ \..v .,.. 3|. \YL {Iv H -v 3 v. N I .‘u‘ . S I‘ ‘ (.— . tb .1 oau UL .- _ 1 1L 7.1 .r/. z 1. .4 . TC .1 1. F» :1. .w.» ru D 1 x I x a L 1 . 1 -- 4b.. r V . fl . r“ n1.u w , at ¢ L \I1 ‘1 A a i 3.. rC («L f. .. 1m 11. _ L 1.; T1 ,6 Ff' . 3.“ 12‘ r- h ’I I Q 1 -h {a f. ‘-‘ ‘. o 'J . CL) Vfi . .LA‘A :10 z "r 1.6 ‘1 3L ‘ F Irv / . .waA 2.9. L V IA. .w J n/ .r J n] l ’- kxt. I\ r‘. 9 r) l- U" ‘- LEO . O 1 r v L ‘IV’V» \J .A.L/ ‘ 5. . a 7‘, 1C KT _ V L112 '“f1{, ‘ N ‘ 4‘ Lick}- ; Y r. . J;;m "VI - \ Jiff C \— 5,." C‘ L- ‘1‘.) ..a \. )1 - ... '0 iv k. . u .L- Y— L w A ¢ 0 ’ r' ~~ L. ( H “v , -‘ a s f“ O C ’ ( I re< \ micruo :t '8 ’0 _l. .4»- E 1; Y- .,J‘ (v '0' (‘6 It“'* 9V.-. .. l 1.1» J O 1 f- ‘7 +’ - y\ 4 - l‘ agrl .. I kJ 5’ Cs ‘1 '(‘." 1‘ guy II V V§ ,4 ' . ‘ i . u a‘ u C «APVC*C‘ ‘v-r V 8 ,L at (A v».. .‘ .31?) LA; I YA D - 1 a s arity I. H Y'I-i +‘ ..«J _. U r . :22“ t'L I L.’ Y o ‘o‘ I- H A .‘ 193 Cr'i :s..\, l ‘ fl 0 1'“ q ‘ '3‘“ \/ LA \J 1'1. C‘ purr‘ ('\ L: O 1; O ‘1‘ \— (4 ‘4' {I 5 CW- up I:* (~\ 3i; V E?) K. at 1,0) r L. n) (I 77ml“. , cu IA I. 1+ ,rv ‘4, .II «is. Q c ‘w d n; #5A& 6. 3; 1““ OI L Lu 1.; of O a -. 1“. J¢..;.A\l~ \ '7‘ § C" L ,. ‘ui E? .. NC .7. d . '1 u]. 2L « Vl‘i t; . :3 tLI‘ . ~“ ”In; 195?. 1959. I a; .l .1 V‘Ulrb .Om; C ‘1 (pm YIA O x, L I h 0 1?. ‘n‘ v.4. "§ . o no, ”A {i l' , H .. cm r”. F o “.57.. n T ‘ I « v.4 J 0 1A (I\ ”w .e ‘ 1‘. LL 5 AH .- h. «J . 54 ll C v- 'm I 0 L0 (‘1 o _-L. 9 A 0 Y. n O 1 7‘ v T is o r .41 \4# v .I y‘. 0 an c U; , O ‘ +Ub f .1. 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C c n f. .: r. u r a 9 P : C n a .1. d r h n. k a C a C . v E, .a a.» C\ 1 0‘; .Iw a.» n. 21. 0 Hi \n “I. t n‘.‘ {L :1 n. 0.. "V . L. NIH... C 1-. SJ :1” n f t .. T. u ‘n .. a. L n, in O “.5 . 0 ..v 3h u C <4 t . t n .. n L f .. fl ... O m. S O n J E L... G 1.. . T .n . fl». .... on ..O. O L ..O . F ....n .2 t P U P. 0: E .1 V C n . v.1 . T V5 :8 C C .1 V C .55.? C .31, I: 0.. ..u .1... .‘HL 2 ”.2 .. t G C F p “...; an. d T r H 19.31. C r, r .J ..v n .1 n . c t S . E . .d .d . h . . e U 1: e u .1 a n ,6 a 1 Q .1 m. a u. .1 h e n R O ...: .. .3 n. n r. 9 2. .. w u. n V‘ a K C a .I V“ . L C 9 u a .1 S K “1. E r. . F a. P a u u b k r 7.. i .... d K... ‘ l G t O . C l .. ...... a S o .3 an .... 3. T O M1 u n rm. .1 S n a ‘ 4 .1 v. v L p. . n I, E t t f a. E ..J T ...m. d 1. 1 no. V L. a C u .0 d O O n d K 0 .....u ...a 1.. I. . n T . ..-. n.“ n ...u a T a .1 .i C/ 0. up. C P F C C. . I. U, I S r... or O .1 M t a r m 2 G e T van; 1 l n u f O L a u t a H... 3 d S O a C . .. 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Study cd‘ci‘nylcni Dag tccnhique for in vivo ‘. imation of forage " ‘V ... 'v v ," ~‘ 1 ’7' g . .. Gitfii‘tiuliitd. U. (J1-nu... Sni.’ Ll, 3£+C.19CL-. Soest, ‘ .G. tibility Van The estimation of forage and determination of drying ubon forages 9‘ means 01 tent of apld-uUUEFEPntIf1.CGT. pFECERted at annual trotein diges- tte effccts of tne ”itvr'nn con- Paper #87. Pm: we meeting, lQéZ, Van Sopst, P.J. A rapid wethod for the determination of fiber and 115 nin using detergme t. Personal Comrunication E.I. Som- fiactors affectixg i a:ca t, dairv ca attl Naster's C State Un ver : ity . 190;. nta Lfi‘zwuxh- 3L efiicb: a.n Vori cuts of ‘écding sttffu S: Lercv. Digestible nUvri i LEQI‘iC .E'FC" 0 D 01:67: . for tie dcrest ic raz>fi . J. 1 9110 0 do, 5.3., B.W. Ki ller and N. UKamOtO, Rumen con- ' effeCLBd b‘ ration and Paper $87, presented at annual mECting. 3 watkin', W.L. and J.V. Yearus, Jr. Lhe nutritive va us of various grasses and grass-legumP mirtures. a, t ‘ ’ ‘ C ; uni ?-.€L $01., 15: 15}. i9,£. 'gest 1511 it)’ of range gr'sses *7 ,7 . n 1;. ‘. i i“ {JV‘ I‘: (W :l . “Ev—I". E)? L' .C/tfoi . _) ...—.‘JICI (J . . . a * ’n _ _-' 4 ‘ . ‘ . ,1 . \ ’“Z‘f CCI‘.’ LS." . Ah‘g SCienCG arl' I Phat-1.1.Ct Oi CCL.A"€,‘I VL‘fiL tCJn. ' r‘ ‘ fl ’1 \ rv‘ ‘ ~ " ‘7 H ..I.‘ ’T’ Q?%:» tau trove e trtgc. aCLL.LJ. 1919. dztson, S.J. aid E.A. :iJPtOR. Technique of digestibil- it‘ trials with sree and its a:r1icati CI to ras- I bits. EmEirc J. Ext.ngr., 4:25. 1936. C.J. a Godden. The comparative dig: of ’rti’pcially dried ca.ture ;eruage _ > ,L u, in:.:x§;I‘., J: 2‘8. uatscn, bility fheep and 'f,. ...}. f‘ -r (1 - . n ‘w 7 'v T! ‘, "I‘f‘ .1 6" ‘: + Vi“): I" V'.1_.. ' U .k.’. LTL‘I-LEL, 81:; 4 I, .f'}. "if. 3,6,? :JJ-AECt C; Catt." jug nts rV11 and stage of mat Iz‘ity on LuC u1¢é:ti- we . C V... C _rC — O ..r... h 0 n. S ..-. 3 . C. ..l 1.. "\v w. r 1; AU. .1. (C .n . . (.... +... m .. at. Q G P C u .5 ..-. .1 O m L . C ...... . .. c; r 1. . .1 3 J u S .1 P: L .l "L... .... d r H «D .1.» o O mu 0 - n «U I 0... x. 1--.. 4 VJ 07/ ran 0 TL h r0 n .... n». O l t .-w C Q , g G -. 6 11m 11. H. .1 Q/ a 1) .Q .1 ...n U C at S rum r“ .u. W ... «U; «15. A...) n ...ruu A...» I W.“ V In?” e w.“ C . .1 a. l ....n P O/ O 9 Cu .1 .1. (L a ...; o .7} n u .i J C .0; &v m... w. Z a .U . V. O 0., n1 . .1 A 5. E t l 9 Q) n h l a n. C I. . a n O/ .o S. t .... Q C . C T 1 .. Cl 1 C ... o r a d .1. .- r; a 2 C C W n/ O .l 1 ...... p X La.) .5 . L C f C a. . 0 up.” Lu n . ¢ 2.. S «J .w; o 7 r4“ .. ‘ 0 Hi!» , 01; 1M I {U CU AOL .A PM» .1) _.+. C .... o C .i M.“ .I w... .. Q .1 o h Q/ l . ; h .1. T. . O 9 7. V t l ..G t .L r; .L n. C G r. o. m 9., ...... T r0 .L 0.; “i rF. whgr‘xw “A 6U e C... Q... ru r0 9 ”40 p. O .l ..c n n 1.. n3 8 Lu 1 I C ..J. C ‘l a W .1 .IJ D . o n. .1 .1 o t a Q... “C ‘n n var. n ,7}. CM L Yul 0 DL u o “71.. t 11* p. L a .1 .1 .1 X a... a... U .i C r) a R 0 1p t mu r- ...u D; Ht... r; r h m/w V C 0. U ..r. U S o 0. .r 9 t 7 .Lu m- 7 d o ...o P n. o a t .n C .l P. ,4 l ... . G . C ,5: n e r. W .. c P ”t T“ Y“ T... ..Tv ..n o A.“ .1. o C .U. 3.. U o. .l d T a 3 G T. C C. P ..C -4 . E . VJ o n e w.» o a 3.: c- ”A a.» .Yu ...ru 7., ...i ”U a G S S F I .. n ..L f a. 1 Q C d C a P. .1 . an .1 6 . ..Mu ..Q r“ ‘44,. D .. J 0 V o mm W. +.u ...C O .11 an 4; o o ..a «L. o .C «A Cp, 9 0 Mn +u Tu ...»; .1... C 3.. o C .50. o .u . "J “W. C O .1 Cu .....1 y . . O :1. C a“ 7.," n. T 9 . W ....” n. t .5 T.. o 9 NE D. T . - .ra . "b .1 .36 ..h .. . f ..1 ..Cr :nh 1 .. a. n; (4., C LL .3 VJ m“. e W rt .. I. a. .. ; .... O .... Q/ 9 0 0C F .1 w. a L h O m G a a .1 . 31 O [.1 a .n 3h ifli of.-. mCJ 3 1L. 11 .-L E .Q d at; l W A n. 0 .r1 .1 .1 .1 .1 O .V ...h z.“ .1. ..h ”HM ) ) ‘ll: ) \l \ II 1, L .3 (C 7 cc 7- ml 7 7. 7.. 7. n .. ( ._ .....L m . rug né f A \J qdy ‘f‘1 3v {-1 L A (Wk. h ,- ,- W' < . ‘ L‘n) _‘.C~ L. . ‘1‘. A‘. a. V V w- .(l u' . QI- - I hill/.11.;O V t x (A l p r; I'ox‘aéj- I .5 .‘ 63 ‘~ ...) L1 V mu >vvosaHK andwo H 1. >HH. ado. macaw wman >Hm. eum. macaw moon >HH. >kh. awa. wwoaa wean 1.. H H H H H H HH HH HH HH N HHH HHH HHH HHH Em. Hc\npw H N.wk N.ro N.we H.pN N.Hm N.mo N.0» N.0N p.mw N.HN N.Nw N.um H.cr H.uo N.HH N N.NH N.NN N.oo H.rw N.Ho N.uo N.Hb H.eH H.mu N.Ho N.Hu N.ow N.N0 H.Nm N.0“ u N.uH N.wr N.N0 H.qw N.0N N.mN N.mm H.eo H.0u N.mN N.Hm N.mr N.0H H.0H N.Ho r N.Nm N.ro N.m© H.u N.0N N.0m N.Nm Hm N.N0 N.E.. N23 N25 N.0? N.um N.m.~ N.5 ..wN N.5 N.5 N.5 N.0N NLL. N.8. He N.0N N.rm N.rm N.Nu H.em N.r# N.0N N.0N v.00 N.rm N.N0 N.rN v.00 H.vo N.Nk No N.Hm N.r< N.mu N.0“ H.0H N.bw N.mo N.oo H.mr N.wu N.0Q N.wr H.om v.00 N.Nu NH N.Hq N.>Q N.uvonnwx epdwa H oosawbcoa wouwmm I HwoN E E . and . 9.85 moon 3.5. E . and . 9.85 moan >4 H H H H H HH HH HH H m. deamfi H N.N0 N.Po H.0o p.mm H.NQ N.ro H.Nr H.0u .oo H.m< N N.wN N.mm H.m< H.No H.0q N.mr N.wo H.Nm .am H.ou w N.Nu N.mo N.oo p.mN N.HN N.uu N.Nw N.0N .co N.0N r N.N0 N.mm N.HH H.uw N.N0 N.uo N.m< N.Hu H.0w N.om w N.wo N.uo v.9» H.9a N.H& N.tq N.NN v.00 H.wN N.0N m N.Hm N.¢H N.Ho H.am N.N0 N.oo N.Nm N.Ho p.mo N.Hr a N.Na N.m¢ H.mm H. mo mudmwofimmooo R use mnongm cadudmpm spa: momwuom nadpm spam no oodwudodddman za oppw> mm mmwao>< HHHMN manwa NHUG0QQ< codcflpdoo 0.Hm H.b¢ m.N4 m.a¢ a.mm 0.0N $.4N .pso chm 0.50 9.04 0.5m a.mm H.Nm 0.4m >.0N .pso cam 4.mm m.mm 0.00 0.m¢ m.wm m.om N.0N .050 and mmmmmMfl 0.4m 0.0m 0.N4 >.NJ m.om 0.4m 4.HN voom m.Nm m.m¢ H.H¢ m.mm >.Nm a.mm N.0N madam m.Nm a.mm «.04 0.44 o.om N.NM N.5N .069 0.Hm 0.00 H.N4 o.m¢ 0.5m 4.0m 0.NN .Hdd mmmmmm¢ o.m m. >.Mm N.4H m.m H.0m 0.m >.H4 4.H¢ 0.0N a.ma >.N N.0N H.NH m.H 0.4m HHH voom m.m m. N.Hm 0.: N.H H.0m m.H 0.N4 0.00 0.0m 0.NH 0.N p.mN. :w.NN m.~ n.4N HHH eschm m. m. 0.4m H.0 0.H 0.4m m. 4.04 m.m¢ n.44 N.5 N.H 0.Nm 0.NH b.H N.0N HHH.0AB 0.0 N.H 0.50 0.HH N.N m.mm 0.0 n.5m a.mm 0.Nm 0.0N m.N n.4N N.NN 0.N o.m~ HHH.MH< o.ma o.m o.n¢ m.m~ 0.m H.04 m.m N.mm 0.04 a.mm $.0N N.N a.mH N.0 0. a.ma HH vomm m.mH m.m a.m4 4.> m.H 0.HJ H.H >.Nm 0.Nm m.mm 0.0N m.N H.HN N.0 b. N.mH HH oeohm H.0 m.H n.04 H.0 m.H 0.0m 0.N n.44 n.0m 0.>m o.m b. 0.0m N.NH H.N o.mN HH.one 0.5 H.N b.mm H.m m.N h.am >.H n.04 N.m¢ 0.H4 >.m 0. a.mm o.H m.a H.0m N.MH< m.m 4.a m.0m m.m O.N N.50 m.N N.H¢ N.0J 0.0m 0.HN H.m 5.0N H.4N m.m 0.0N HH.HH< N.m o.H 0.0m 4.5 #.N 4.m0 m.m m.mm 0.Hm 4.0m a.0 m. N.0N 0.HH H.H 0.0N H.8Ha m.m m.H m.m0 0.0 >.N 0.H0 m.m m.am 0.00 0.0m >.NN N.m N.0N 5.0m H.¢ 4.0m H comm N.N v. 0.N0 m.> m.N 5.0m o.N 0.0: m.~¢ 0.0m m.HH ¢.H p.mm 0.4a 0.H 0.0N H maonm H.b o.N 0.4m 0.0 m.N 0.0m 4.N o.¢m 0.00 0.H0 m.NN N.0 b.5m m.HN o.m 0.0m H.069 «.0 m.H H.5m N.0 >.H m.~m m.N m.>4 a.m4 N.mm 0.0H N.H 0.Nm 4.m~ N.0 N.mN H.MH< .m.m .un 04 .>.o .m. .nn 0m .m.m .6: 4m .un ma .6: NH .>.o .m.m .6: 0 N.>.o .6: m m 221 .604004n0> mo pd04o4MMOoo mm .uoupo 09006000 4 0.00 4.00 0.04 0.m4 0.00 0.00 4.0m .pso cam 0.N0 0.0m 4.mm 0.04 «.00 4.4m 0.0N .000 004 mmmmmmm 0.00 4.40 0.40 0.04 4.00 0.0N 0.00 .340 0.00 0.Nm 0.04 0.00 4.00 4.4m 0.0N 00». 0.00 0.00 0.00 4.44 4.~m 0.00 0.40 macs- 4.00 4.00 0.Mm 0.04 0.04 0.40 0.40 .090 0.00 0.00 0.40 0.Nm 0.04 0.00 4.0m .044 mmmmmwfl 0.m 4.4 4.00 4.0 0.4 0.04 m.4 m. m.m4 0.0m 4.0m 0.04 4.4 4.NN 0.0 0. 0.0N 44 000m 4.m 0.4 0.00 n.~ 0. 0.00 4.0 0. 0.00 0.04 ~.mm 0.0 4.4 4.00 0.4 0. 4.0m 44 madam 0.0 4.4 0.00 0.4 0.4 0.00 4.4 4.4 0.00 «.04 0.04 4.4 0. 4.00 0.0 0. 0.00 44.060 4.0 0.N N.0m m.n 0. 0.40 4.4 4.4 N.0m 0.00 0.44 N.0 0. 0.00 0.0 0. 0.00 44.044 0.4 m. 0.00 0.0 0.4 4.40 0.4 0.4 0.40 0.04 4.00 m.m m. 0.0N 4.0 0. 0.0N 42940 4.4 0.4 4.40 4.4 N.4 0.40 4.0 0.4 0.04 4.44 0.40 0.04 4.4 0.0N N.0 0. 4.0m 4 000m 0.4 0. 0.m0 4.m 0.4 0.00 0.0 0.4 0.00 0.N4 0.4m 0.0 0. 0.0N 0.0 0. 0.0N H oaohm m.N 0. 0.00 0.0 0. n.0m 0.0 0. 0.40 4.40 0.04 0.0 m. 0.00 0.4 N. 0.00 4.000 m.N 0. 4.00 0.0 0. 0.00 0.4 0. 0.00 0.00 0.04 N.0 0.4 N.0m N.0 0.4 m.0m 4.044 0>0U 0M0” 02 g 0>0U emem 02 on 0>0o ewem 0.H5 4N 02 ”H 02 NH 0>0Q emem 02 Q 0>00 emem 00H: m 0 0000900 N004 823.58 H4004 “.408. “42084 Appendix Table XXIV 222 Analysis of Variance of in vitro DM Disappearance of Pure Stand Forages Source D.F. Sum Squares Mean 5. Square F F1 1961 Forages SpeCies 3 l, 622 .70 515009 27 072*“. l 017 Time 6 3401649069 50716106 2916029“ 12052.3(.” Cutting 2 3 , 869 .87 l, 936 .9 99 .17** 6 .18* S . T 18 1,526.55 86.8 6.35“ S . C 6 1,997.66 332.9 17.06“- T . C 12 535.16 66.6 2.29“ S . T . C 36 . 2 1 .1 .98 Subtotal 83 66, 689 .15 Error _22 6,912.29 19.51 Total 335 69, 606 .76 SE = 2.21 5.1). = 6.1.2 c.v. z = 11.18 1962 Forages Species 3 2, 793 .83 931 .3 180 .16** 5 .12** Time 6 28,727.72 6,737.9 926.09“ 26.06“ S . T 18 1,977.80 109.9 21.25“ S . C 3 215.85 71.9 13.91“ T . C 6 67.80 7.97 1.51 S . T . C .1_8_ 156.85 8.60 1.66 Subtotal 55 3‘}: M0 0 53 Error 198 868.06 5.17 Total 223 36,308-59 3?: = 1.16 S.D. = 2.27 c.v. z = 5.13 1‘? value using the significant interaction terms as the error term. * Significant (P < .05) *se Significant (P < .01) 223 .meapflnuo>fi:d Hene>on an mucoeauogxe soapMdHe>o awesou e>aoeneaooe :a won: me: 500:: nausea song vendepno he: euaemde vepeuvhzov e< H 05.0w ~0.~m 45.nm 4H.nm Ha.mm «a.mm 50.04 00.0: 04.00 00.40 50.0“ am.mn we na.am 00.04 00.nm ~0.mm 00.54 «0.Nm 05.04 m0.0e H0.0e 05.04 00.0m ~0.0m on 05.04 ~n.04 44.04 00.54 00.0m 00.04 04.04 00.04 H0.04 0a.“; 00.Hn 40.0m em 0H.0n 4~.44 «N.04 05.H¢ . 0a.“; 04.04 HH.¢4 m~.0e a0.a¢ 00.04 an.0n ma -.He ma.4¢ «a.me ~0.me - an.ae mn.0m 00.00 0m.a¢ . ma.~4 ~0.e4 ma 50.4m 04.00 «0.00 m4.em em.~m H0.em no.0m 00.00 00.nm 40.n0 05.00 00.nm 0 40.00 00.00 0H.Hm 00.nm mn.0m ne.0~ H~.0~ 00.0w 40.nm H0.Hm 00.00 ~0.0m 0 Mr. .1“ a“ w m H name *3 3 52. 0a 33. 0 0 83. Sfiéefififigbafifi 00.0m mm.~m 00.0“ 00.Hn 00.04 H0.mn mm.04 an.0n n~.mn p.44 m.en 0.0“ 0.00 no.0e am.mm 0m.ne -.0m «p.04 mm.ae 40.00 40.04 0.Hm m.nm 0.04 H.5e 04 05.H4 . 40.00 «a.mm 0~.me 05.0“ an.am 0.54 4.00 4.~m e.me 00.ne a 0H.aa 0~.0m «0.5; mm.a¢ an.am “0.0“ 4.00 0.0m a.me 0.04 00 no.0; . 00.0e 00.00 00.50 00.0“ m0.an 0.H4 N.0“ 0.0m «.04 ~0.me 00.04 00.He ma.0e 40.n4 an.ae mm.me 4H.00 4.He e.an p.04 a.me «N 00.00 an.ae m0.ee Hm.mm «a.mm >0.~4 00.00 m.~4 n.54 a.me H.04 00.04 ~4.~4 0m.~4 0H.4n 40.n4 0~.~4 40.04 0H.04 0.0s 0.04 0.04 0.04 ma an.am 00.00 ma.~4 00.00 00.0w 0m.04 0.00 0.08 «.5: 0.mm 0.00 an.am ~4.mm na.mm 0n.m~ no.0e 00.00 05.H¢ ~4.~4 0.0m 4.H4 0.0m 0.00 «H «5.00 an.am 0~.Hm 0~.0m H0.0~ 50.0m 05.0m 0.00 0.Nm 0.00 0.50 an.am an.am 00.00 sn.>~ 44.nm na.0~ H0.0~ H0.0m a.mm 0.00 0.0m 0.mm 0 u . 0n.0~ an.am 00.H~ 50.nm mm.0~ H.Nm an.am 0.0m 0.am 4m.H~ 00.0H m0.m~ ma.m~ an.am 0m.ma ~5.0~ «0.0H 0.00 0.00 0.0N a.am 0 n3; nonpnpnoata 33 u a a m m a m a m a a m unnananoa 0H ma mm mm 0H 4H 0H ea 0H m m am annex :3: ..an .nnm :3. .80 .50 .50 .80 .30 .80 .80 Show ma<0 H sxx manna xanqonn< ennnnnnm new neanoa< 00 Amy nonnnnmnnnnan :0 Appendix Table XXVI Rumen Inoculum DM and Men-filterable UK From 19 Vitro Fermentation Blanks 22L Non-filterable DH DM Date g[60 m1 non-settled _fiumen Inoculum. Avg. 1961 Forages Sept 021 025518 02690 " .2642 02628 -' - " Dec. 3 .1665 .1665 .1A88 .1595 .1598 1.1792 1.1856 1.1824 Dec.10 .2513 .2679 .2h23 .2529 .2536 1.1972 1.19h0 1.1956 Dec.17 .2h98 .2363 .237A - .2411 1.2301 1.2266 1.2284 Jan.10 .3512 .3500 .3871 .3761. .3661 1.1.051 1.1.11.5 1.1.093 Jan.1h .2137 .2172 .2192 - .2167 1.1776 1.1859 1.1818 Jan.19 .3808 .3681 .3703 .3357 .3637 1.3668 1.3709 1.3688 Jan.28 .2167 .30h9 .2842 .3190 .2887 1.2171 1.2206 1.2188 Average 114 % 0‘65 2009 1962 Forages g/Zh m1 of settled July 3 .0238 .0229 .0209 .0188 .0216 .3396 .3933 .3916 July 10 .0303 .0257 .0268 .0233 .0265 .4621 .6642 .1632 July 15 .0192 .0239 .0283 .0218 .0233 .h529 .hh87 .h508 July 22 .0243 .0241 .0307 .0230 .0255 .h261 .hl79 .4220 Aug.1 .0205 .0225 .0178 .0279 .0222 .4200 .4226 .4213 Average DH % .10 1.82 225 Appendix.Tab1e XXVII DM Disappearance of Forage Substrates Due to Buffer and Due to Rumen.Inoculum.(Difference Between DM Disappearance with Buffer and Total in vitro DM Disappearanc) DM Dis. . DM Disappearance Due to Added Rumen Inoculum “Eth‘jfl” 3 hr. 6 hr. 12 hr. 18 hr. 22. hr. 36 hr. 48 hr. 1961 Alf.I 28.4 .8 2.6 10.8 16.7 19.4 24.1 28.7 II 21.8 7.2 6.9 18.0 22.4 19.4 25.4 29.1 III 17.8 5.2 6.7 14.2 22.1 19.5 20.5 29.2 Tre.I 23.8 4.6 13.9 17.2 25.2 31.1 30.8 30.8 II 22.6 2.4 7.4 15.0 16.9 21.7 28.2 26.7 III 26.0 2.2 6.0 18.3 19.3 22.4 28.0 28.6 Brome I 2106 " 07 61.01 1140‘} 2007 2700 3301 [0102 II 16.8 -1.6 4.3 8.5 15.2 15.9 24.8 26.3 III 22.6 1.9 7.1 14.2 18.2 19.4 27.5 28.6 Reed I 24.9 1.5 3.3 13.1 21.1 26.4 36.7 38.4 II 1709 .1500 02 800 2209 1503 3002 2901 III 23.2 .8 5.0 5.7 18.2 18.5 30.9 30.5 Tim. 22.0 -2.0 4.2 16.4 29.9 33.3 41.4 36.6 A1£.-2 27.0 3.1 5.5 14.4 16.2 19.3 24.7 25.7 1962 Alf.I 29.6 6.92 9.64 20.12 24.07 28.21 31.33 33.48 II 26. 7.12 9.21 17.40 23.56 23.89 24.39 49.09 Tre.I 26.3 4.22 7.26 17.50 25.10 27.88 30.00 31.25 11 24.8 7.22 10.61 15.88 21.45 28.66 29.11 31.67 Brome I 24.6 .86 2.89 6.98 17.45 25.39 35.96 39.27 II 22.2 .89 2.88 11.03 18.62 27.72 35.71 41.50 Reed I 26.2 - .07 .41 5.54 15.18 22.53 28.69 35.20 II 2008 - 002 1032 8033 170211» 220107 2809“ 37055 Tim. 24.4 1.55 4.34 14.71 25.11 30.42 36.70 42.34 226 vosqwusoo 0.mm H.0m 0.00 0.Hm 0.N0 4.40 0.00 H.0m .40 NH 4.40 0.40 0.04 0.04 0.40 n.40 0.Nm 0.Hm . m .H.aae «.00 4.04 0.Nm 0.04 4.00 ~.a0 N.00 4.m0 .40 NH 0.0m 0.04 4.44 4.04 0.00 4.00 «.40 n.0m .6: m H.o.m 0.0m m.mm o.mn 0.0m n.0m n.00 4.00 0.Nm .6: NH 4.0m H.0m 0.0m 0.0m n.0m 0.00 0.00 0.Nm .6: m H.009 0.Nn 0.Nn 0.04 4.04 0.40 0.00 0.40 4.~0 .4: ma 0.00 N.N0 0.04 H.m4 0.40 4.00 0.00 0.00 .4: m H.HH¢ nomwnom NO0H 0.00 n.00 0.0m m.0~ 4.44 «.mm n.0m ~.~0 m.40 o.mm 0.04 n.0m HH 000m 0.40 4.40 0.00 N.mm «.mm 0.4m n.4m «.00 o.M0 4.04 m.mm 4.mm HH nsosm a.mm 0.Nm 0.4m N.0N 0.0m o.n~ 0.00 0.00 H.N0 0.04 0.0m 0.44 HH.oua 0.44 4.04 0.04 0.4m N.Nm 4.0m N.0m 0.00 N.00 «.04 0.~4 0.44 HH.HH< m 0 m, m] .psH emndq esp cw zessm esp n0 .psH emndg 020 0H nossm on» :0 mowwnom 0038040 .8040 003303 .002 03.0808 20 00880.8 E 4004 H H 804580 0300 QHGMfiH opp an uosHahopon mu 0anm002H owndq nosed 05 550 05 5 00408040 06040 05 20 SEQ 3000 508004 227 .40400 0040004400 40000 000 004000 00004 0004000040: 040044 000 000000000 4 40. u 4.0 n 0. u 4.0 0.4 u 0.44 0.44 0.04 0.44 4 0000 00.04: 0.00. 4.04- 0.04- 0.04: 0.44 0.04 4.44 0.00 4.044 00.04. 0.44- 0.40: 4.04- 0.00: 0.40 0.00 0.00 0.40 4.004 40.4 4.0 0.4 0.0 0.0 0.04 4.44 0.04 4.44 4.444 0000000 0004 0000.44. 00.0 n 0.04: 0.44- 0.00. 0.04 0.04 0.04 4.04 44 0000 000.0: 4.0.. 4.04 0.0: 0.4: 0.04 man 4.00 0.04 4400000 04.00: 0.04- 0.40: 0.40: 0.40- 0.40 0.00 4.00 4.00 44.004 40.04 0.04 0.44 0.04 4.0 0.44 4.04 0.44 0.04 44.444 .0 0000400 .004 004000040 040044 004000040 00040 4004 40000 00400040000 0020 040404 0040004400 40004 04 0004800400 00 04:0404M00o0 :ao44000400 040044 0:0 40940 .000040000 444044 04004 04000000 “CWJWEIEWL'Nflflflfllfiflfiflr