H’zGH MOSSTURE, ACID TREATED WAXY. OMQUE-Z ANS YELLOW DENT CORN RATiONS FOR GROWiNG STEER CALVES AND GROWING-FiNlSHlNG SWWE Thesis for the Degree of M. S. MICHIGAN STATE UNWERSITY STEPHEN SCOTT SACHTLEBEN 1975 115182818 ' .J'm n 4 .4.- LIBRARY “” a" ‘ o l'v u!" ’I 3 W 1“ I...” luswigan L»: a? .19 i" ”‘3.“ av ‘9 "DRE 8: SONY 800K BINDERY INC. . ABSTRACT J HIGH MOISTURE, ACID TREATED WAXY, OPAQUE-Z AND YELLOW DENT CORN RATIONS FOR GROWING STEER CALVES AND GROWING—FINISHING SWINE By Stephen Scott Sachtleben The quality as well as quantity of available protein in the two mutant corns, Opaque-2 and waxy, has been the center of debate in recent years in regards to their nutri- tional value, whether advantageous or disadvantageous, in the performance of beef cattle and swine. The superiority of opaque-2 in respect to swine seems to have been estab- lished although there have been conflicting reports. The value of waxy corn has not really been defined for swine or cattle. Beef cattle seem to have gained nothing from the superior amino acid balance of opaque—2 rations since there is adequate microbial synthesis of essential amino acids when adequate nitrogen is provided. It was the pur- pose of this study to examine the possible advantages or disadvantages of each corn type in regards to both the growing steer and growing, finishing pig. EXPERIMENT I — Cattle Feeding Trial A 3x3 factorial design was utilized to compare average daily gains and gain per feed ratios with different Stephen Scott Sachtleben combinations of sixty percent silage and forty percent high moisture, rolled corn rations. Seventy-two Charolais- Hereford crossbreed steer calves were randomly lotted into nine treatment groups representing each silage-corn combi- nation of waxy, opaque-Z and yellow dent corns and silages. Silages were treated with an ammonia mineral suspension in order to raise the protein level from 8% to about 13% on a dry matter basis. All shelled corn types were acid treated with a 60% acetic - 40% propionic solution-because their initial moisture levels were too high for conven- tional storage without appreciable losses due to spoilage. Cattle were fed ag_libitum, weighed biweekly and re- moved from experiment after 159 days. Average daily gains were not significantly different across treatments although there was a tendency for waxy corn rations to increase gain and for opaque-2 corn rations to depress gain when compared to dent corn. Feed efficien- cies did not differ significantly, however, opaque-2 rations required more feed per pound gained than either waxy or regular corn. EXPERIMENT II - Swine Feeding Trial Thirty-three swine were randomly allotted to four different treatment groups. Each group represented a diet composed of either dry dent, high moisture dent, high mois- ture opaque-2 or high moisture waxy corn. Each lot was Stephen Scott Sachtleben fed this ration until market weight was reached. All diets were formulated on an equal dry matter corn basis and supple- mented with soybean meal to comprise a 16% protein diet during the growing phase and a 13% protein diet during finishing. Average daily gains did.not differ significantly al- though waxy corn tended to decrease gain by as much as 8% when compared to the other rations. Carcass data were ob- tained upon slaughter with no dissimilarities. EXPERIMENT III — Balance Trial Each of the four feeds utilized in the swine feeding trial during the grower phase was employed in this trial. Eight pigs were divided randomly into two lots and a nitro- gen and energy balance was conducted with each lot on each of the four rations. There were no significant differences in energy or nitrogen absorptions or retentions across treatments. Waxy corn consumption seemed depressed possibly due to its flaky texture. HIGH MOISTURE, ACID TREATED WAXY, OPAQUE-Z AND YELLOW DENT CORN RATIONS FOR GROWING STEER CALVES AND GROWING-FINISHING SWINE By Stephen Scott Sachtleben A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Animal Husbandry 1975 ACKNOWLEDGEMENTS I would like to express my appreciation and gratitude to the following people whose efforts have aided me in my graduate program and the preparation of this thesis. Dr. E. R. Miller for guidance in my research work and his critical reading of this manuscript. Dr. R. H. Nelson and the Animal Husbandry Department for the use of the facilities and animals. Dr. W. G. Bergen for his overall counseling in my academic work and his laboratory assistance. Drs. H. E. Henderson and E. C. Rossman for their super~ vision in setting-up the original cattle experiment and numerous consultations. Dr. W. T. Magee and C. A. McPeake for their invaluable aid in the statistical analysis of the data. Special thanks to E. L. Pink and F. F. Green for their laboratory assistance. My wife, Sara, for her diligent work in preparing this thesis and her understanding love that has meant so much. ii TABLE OF CONTENTS LIST OF TABLES I. II. III. IV. INTRODUCTION LITERATURE REVIEW . Acid treatment of corn Opaque-2 corn Waxy corn MATERIALS AND METHODS Experiment I . General design of cattle experiment Silage harvest . Shelled corn harvest Feed sample collection Feed analyses . Statistical analysis EXperiment II General design of swine trial Rations utilized Sample collection Sample analyses Statistical analysis Experiment III . General design of Balance Study Rations utilized Sample collection Statistical analysis RESULTS AND DISCUSSION Experiment I . Average daily gain Feed efficiency Analysis of feeds Experiment II Average daily gain Feed efficiencies Analysis of feeds iii Page VI. VII. TABLE OF CONTENTS (continued) Experiment III Balance study GENERAL CONCLUSIONS BIBLIOGRAPHY APPENDIX iv Table LIST OF TABLES 10 ll 12 13 14 Experimental Design for_Experiment I Dry Matter Percents and Yields of Corn Silages . . . . . . . Dry Matter Percents and Yields of Shelled Corns . . . . . . . Grower Phase Ration Finisher Phase Ration Average Daily Gains for Cattle Feed Efficiencies for Cattle Average Daily Feed Consumption by Cattle Amino Acid Contents of Corn Swine Performance Data Amino Acid Percentages of Swine Grower Ration Amino Acid Percentages of Swine Finisher Ration Swine Carcass Data Swine Balance Study 30 36 37 43 45 47 49 51 S4 55 S6 58 INTRODUCTION One of the most critical problems of those who raise animals, whether ruminant or monogastric, is the price of feed. Many things can affect feed prices such as inflation, supply and demand and labor costs in the feed industry. Therefore, it would be to the advantage of the farmer to obtain the best performance in terms of feed efficiency and average daily gain or in reality, gain per dollar expended on feed. Thus, this study was devoted to the examination of utilizing different corn types and their protein compo- nents in regards to performance both in ruminants and mono— gastrics. Opaque-2 corn is a mutant which has a superior amino acid balance than regular corn. This superior amino acid balance is mainly due to increased lysine and tryptophan levels. Since lysine and tryptophan are often the dietary amino acids limiting growth performance, it is in this capacity that opaque-2 would perhaps be superior to regular corn. The amino acid pattern of waxy corn is similar to that of regular corn, however, waxy corn is higher in the protein component zein. Zein is supposedly much less degraded in the rumen since it resists attack by proteolytic enzymes (McDonald, 1954). The insoluble protein portion which passes to the lower gut could in turn be hydrolized with subsequent 1 absorption of amino acids. It has been suggested that opaque-2 corn would be advan- tageous in swine production since swine have no rumen microbes to synthesize amino acids and the additional, better balance of essential amino acids would facilitate betterperformance. Cattle may perform as well on regular corn as opaque~2 since their rumen microbes may synthesize any additional amino acids needed for performance, thus the better quality of protein in opaque—2 may not be utilized.' Waxy corn may add to the amino acids available for intestinal synthesis in cattle due to rumen bypass of zein; in essence making more amino acids available for body utili-~ zation. In swine the question arises as to whether the rela~l tive difficulty in the digestion of zein would lead to poorer performance. These questions were examined in this study in order to determine the nutritional status of each corn type in respect to cattle and swine performance. LITERATURE REVIEW Acid Treatment of Corn The question as to whether one successfully stores grain is dependent upon the inhibition of mold growth and the regulation of bacterial growth. These two fac- tors, the prevention of mold formation and strict gov- erning of bacterial growth, are regulated by the percent moisture of the corn, oxygen supply and the pH of the stored feed (Long, 1973). In the past, it has been the procedure to air dry the corn to an approximate 14% moisture level before ensiling. However, Beeson and Perry (1958) were the first to report that they had obtained improved feed efficiency, in cattle, by feeding ensiled, high mois- ture, ground ear corn. Contemporaries of Beeson and Perry have sustantiated the initial findings that feed efficiencies had indeed increased due to the ensiled high moisture corn (Heuberger 33 31., 1959). There is, however, an upper limit of percent mois- ture and if surpassed, a depression in average daily gain will occur. Tonroy et 31. (1974) have shown that o\° a moisture content of 33.8 depressed gains by ten per- cent (P<.OS). Heuberger gt a1. (1959) also reported a marked depression in gains when cattle were fed a corn ration with 36% moisture. A reduction in dry matter intake may also occur if moisture levels are too great (Heuberger 31 31., 1959; Burkhardt 31 31., 1969; Tonroy 31 31., 1974). When the corn is not fed at excessively high moisture levels, the dry matter intake will be indirectly pr0portional to the percent moisture. This results in improved feed efficiency. In 1974 Tonroy 31 31. demonstrated that cattle fed high moisture corn had improved the feed efficiency (gain/dry matter) from between 9-25%. The usage of high moisture corn was limited however to ensiled, sealed systems. With increased yields of newer hybrids, early harvest continued and a need for larger, less confining, cheaper, storage areas arose. In 1971, the United States' researchers were given the Environmental Protection Agency's clearance for the addition of certain volatile acids, mainly acetic and pr0pionic, to high moisture grains in order to inhibit bacterial and fungal growth while stored in simple, uncovered bins. Preliminary tests by Miller 31 31. (1969) at Cornell University, showed that shelled corn reconstituted to 30% moisture and treated with 1.5% propionic acid re- mained mold free for three months under laboratory conditions that far exceeded actual summer heat and humidity. Supplemental feed-lot trials by Miller 31 _1. (1969- 1970) resulted in no significant differences in feed efficiency or average daily gain when high moisture corn treated with volatile fatty acids was compared to dry corn on a dry matter basis. Work in high moisture corn improvement was carried on by Forsyth 31 31. (1970). Their research with corn treated with propionic acid led to the conclusion that, in beef cattle, corn, treated with 1.5% propionic acid, would increase feed efficiency by 10% over artificially dried corn. A significant increase in gain/feed ratio (P<.05) was obtained in weanling pigs if high moisture corn was treated with .67% propionic acid (Meisinger 31 31., 1974), .Acetic and propionic acid mixtures have also been studied as to their effect on the nutritional value of high moisture corns. Preliminary trials at Cornell by Miller and coworkers (1969) depict that there was no significant advantage to treating the high moisture corn with an acetic: propionic mixture although there was a tendency for the preserved corn to obtain slightly better results in gain and feed efficiencies. Tonroy ._1 31.(1974) reported that their data showed a seven percent feed efficiency increase in cattle when the corn had been treated with volatile fatty acids in the following proportions: acetic 57.0%, propionic 40.0% and 3.0% water. Numerous researchers across the country have run trials with various other animals. Lambs fed.corn treated with 57% acetic, 40% propionic and 3% water (ChemstoreR) apparently did not show any significant performance differences according to Polzin and fellow workers (1972). Swine (Lynch 31 1., 1974) significantly benefitted (P<.05) in average daily gain when a 1.2% propionic- acetic mixture was used on high moisture corn and compared to a dry corn ration. It should be noted that in this particular trial, the corn sprayed with the volatile fatty acids had reduced carotene and vitamin E levels after 20 weeks. The addition of water to previously dried corn will result in lower gains and feed ratios than if one used corn with high moisture right from the field. According to Tonroy, Beeson and Perry (1974), the nature of the moisture and fermentation contribute to the final results. Artificially added moisture to corn produces a different fermentation product than natural high moisture corn during ensilement. Although reconstituted high moisture corns were somewhat inferior in gains and efficiencies, this type of corn was digested more thoroughly on a dry matter basis (McLaren and Matsushima, 1968). This more thorough digestion (P<.05) of dry matter did not however make up for the increased protein digestim bility shown by Tonroy 31 31.(1974) in the high moisture and acid treated corns. A11 high moisture corns whether reconstituted, un- treated high moisture, or high moisture corn treated with volatile fatty acids, have significantly (P<.05) increased dry and organic matter digestion and contain more digestible energy than dry corn (McKnight 31 31. 1973) for beef cattle. Clark and Harshbarger (1972) showed similar results for lactating dairy cattle. Starch digestibility tended to be higher in high moisture corn diets, but only corn that had been acid treated was significantly higher (P<.05) according to McKnight 31 31. (1973). Increased starch digestibility combined with significant increases in nitrogen diges- tibility may be a factor of importance concerning the superiority of high moisture corns. Polzin 31 31. (1972) showed no significant differences (P<.05) in N digestion and retention in lambs. Upon digestion of acid treated corns, rumen fluid volatile fatty acids (acetic, butyric and propionic acids), did not seem to differ, but on measuring the total volatile fatty acid concentration, the level had risen by approximately three percent as shown by Miller and coworkers in 1972. The rumen pr0pionic acid level increased by 12-13% as compared to regular dry corn. One can deduce from this that other fatty acids had decreased in concentration. It would stand to reason that the pH of the rumen drOpped accordingly. In reference to the.rate of passage of these corns, McKnight 31 _1.(1973) stated that high moisture corn, as a whole, had a significantly (P<.05) slower rate of digestion than dry corn. This could be related to the particle size and density of the corn. As a result of the high moisture corn not leaving the rumen as rapidly as dry corn, it may be hypothesized that it was there— fore more thoroughly digested.' The acid, from the re- sults of spraying the corn for preservation, along with the fermentation process could aid in the breakdown of the hard endosperm of the kernel, thus aiding in the di- gestion. The high moisture content in itself could assist in softening the outside and keeping the kernel, as a whole, more pliable. There are various other chemicals employed to pre~ serve high moisture corns although their use in most cases can not be justified when compared on a cost per gain basis. Bothast and workers (1974) when comparing ammonia, ammonia isobutyrate (AIB), isobutyric acid (IBA) and propionic-acetic acid treated corn in Herefords found no differences across treatments in reference to average daily gain or average daily intake with the exception that the ammoniated corn was significantly (P<.05) lower in feed efficiency. In treated high moisture corn diets for swine, Lynch 31 l. (1974) showed no differences when comparing .4S% NH3, .82% propionic, 1.2% PA, 1.5% IBA and .6% methylene bis propionate. A solution of .67% methylene bis propion- ate utilized by Meisinger, Kroening and Hodson (1974) at Southern Illinois University did show significant differ- ences (P<.05) in weanling pigs. Feed to gain ratios were higher than ensiled high moisture corn and corn treated with a .67%propionic acid solution. While there seem to be discrepancies among data as to which treatment of high moisture corn gives the best results, several conclusions can be drawn. First, treat- ment of high moisture corn by the aforementioned chemicals, does retard bacterial and fungal growth whereas untreated corn, high in moisture, would rot due to acetic and lactic acid formation combined with overheating. There are dif- ferences in length of storage dependent on type of chemical employed and management practices. Secondly, ammonia treatment increases feed to gain ratios significantly. This is due to the additional blood urea formation. Thirdly, according to Florence 31_31.(1968) grinding of high moisture corns may enhance their solubility and as a result increase digestibility in the rumen. The author feels that the effects of chemical treatment of high moisture corn can be summarized by the words of McKnight and his coworkers (1973): "Significant dif- ferences in beef cattle and dairy cattle performance are likely. if physical and chemical characteristics of high moisture 10 corn are altered by processing in such ways as to affect rumen fermentation patterns, extent of digestion in the rumen, and the overall digestion." Opaque-2 Corn Corn, without supplement, is a low protein type of ration. The protein level usually is within the range of from eight to nine percent. Many farmers formulate a Speci- fic corn variety by genetic cross-breeding that would result in a corn with higher protein levels. These higher protein contents would theoretically enable an animal to have superior growth performance provided the protein was of better quality. Genetically, opaque-2,(O-2), is a strain of corn which differs from normal corn in that opaqueez contains a mutant, recessive, 0-2 gene which changes the protein con~ tent of the corn kernel (Mertz 31 _1., 1964). This gene reverses the major components of corn protein, mainly glutelin and zein. In opaque—2 corn glutelin levels are higher than normal varieties and zein levels are decreased. This reversal of corn protein ratios is reSponsible for an increase in the amino acids lysine and tryptOphan by almost 100 percent and slight elevations in histidine, arginine, aSpartic acid, threonine, glycine, valine, cystine and isoleucine. Mertz also points out that high lysine corn has decreased amounts of leucine. 11 Mertz and fellow workers (1964) have shown, through laboratory analysis, that lysine levels in opaque-2 corn were at least double that of normal corn. The zein levels had dropped from a mean of 46% in normal corn to 15.7% in high lysine corn. Zein, according to Osborne and Mendel (1914), is the major constituent of regular corn protein and is practically devoid of lysine and tryptophan. There- fore when zein decreased and glutelin increased, researchers speculated that it was the lysineetryptOphan rich glutelin that caused superior performance in rats. The first study conducted with the opaque-2 mutant known to this author was performed by Mertz 31 _1. (1956). In this trial rats were utilized. They showed opaque-2 corn to be superior to regular corn and equivalent in re- sults to‘a soybean meal supplemented ration. The male rats on 0-2, in reality, gained 3.6 times faster than the rodents on normal corn diets. Upon analysis, the 0-2 corn showed higher levels of lysine and tryptOphan. Because of these increased amino acid levels, it was theorized that this was the reason for apparent opaque-2 superiority in rats (Mertz 31 31., 1965; Gipp, 1968; Gipp and Cline, 1972 and Klein _1_31., 1972). Veum, Pfander and Bellamy (1974) showed no signifi- cant differences in performance of rats when they were fed normal and opaque-2 rations supplemented with soybean meal or additional amino acids. 12 Further experimentation by Mertz in 1966 demonstrated that no single essential amino acid was the limiting factor for growth in rats and that opaque-2 rations were equal to a casein diet supplemented with cysteine. In poultry, lysine seems to be the superior component of opaque-2, not a lysine and tryptophan combination. Rogler (1966) declared that on an equal nitrogen basis, opaque-2 corn was not better than normal corn without me~ thionine supplementation. Here methionine was a limiting factor and even surplus lysine would not affect growth. However, Rogler showed that with addition of methionine to the diet, the opaque-2 corn would produce better gains and feed efficiencies than normal corn. Cromwell _1 31. (1966) at Purdue demonstrated improved 'overall gains (P<.01) in chicks fed normal corn over opaque-2 corn on crude protein rations of 21, l9, l7 and 15%. There was no amino acid supplementation in this trial. Dependent on the protein percentage, feed efficiency dif- fered from level to level. Chicks on a 15% ration were more efficient (P<.01) when fed opaque-2 , but on a 17% diet, normal corn was superior (P<.01). Additional analysis by Cromwell 31 _1. uncovered a methionine deficiency in re- spect to National Research Council (1960) guidelines. In response to this finding and the work of others (Rogler, 1966 and Featherston 31_31. 1960) methionine was added to the diet, thus alleviating the limiting factor. As a re- sult, chicks fed 0-2 over a given weigh period were 13 significantly heavier (P<.01) at the 15% protein level and tended to be heavier at other levels although not signifi- cantly. Feed efficiency for chicks fed 0-2 was significantly better than those fed normal corn at 18% and 15% levels and relatively identical at 21% protein. This would lead one to believe that, in poultry, opaque-2 corn is superior to normal corn predominantly at suboptimal protein levels on methionine supplementation. Cromwell (1966), to further substantiate the theory that lysine was the "superior factor" in opaque-2 corn, con- ducted a trial using chicks fed opaque-2 and normal corn without lysine supplementation. The 0-2 chicks gained 13% faster (P<.01) and 16% (P<.01) more efficient than chicks on normal corn diets. However, if the levels of lysine in the normal corn were supplemented until they were equal to the ly- sine levels found in the 0-2 corn, the results of daily gain and efficiencies would be statistically identical. When soybean protein was added to the opaque-2 and normal corn rations in order to balance them isonitrogenously, the nor- mal corn diet received more soybean and less corn than the opaque-2 diet. The normal corn rations caused significantly (P<.05) higher final weights than the opaque-2 rations over all protein levels; feed conversions were similar. This data may be explained as the result of equal lysine levels in both diets and thus the reason why the Opaque-2 corn was no longer superior. The superiority of the normal corn ration can be explained by suggesting that the soybean 14 protein was superior to Opaque-2 corn's protein. With the possibility of increased lysine levels in rations resulting in better gains and feed efficiencies in chicks, the question arose as to lysine's effect on other larger animals both monogastrics and ruminants. Beeson 31 31. (1966) and Pickett (1966) in their work showed that weanling pigs fed an Opaque-2 corn diet, forti- fied only with vitamins and minerals, gained 3.6 times faster than those swine on a normal hybrid ration. When the protein level of the normal hybrid diet was elevated to that of the opaque-2 the gains were similar. Beeson, Pickett and coworkers concluded that opaque-2 corn was equivalent to an isonitrogenous diet of normal corn fortified with soybean meal. Additional work by Cromwell (1967) revealed significant increases in average daily gains and gain/feed ratios when Opaque-2 was compared to normal corn in swine rations. Excess nonessential N addition to normal diets had no effect on results. Cromwell (1967) stated that superiority shown by Opaque-2 may have been the reflection from varying levels of essential amino acids between the two corns. Based on National Research Council (1964) stan- dards, the normal corn was deficient in tryptOphan, valine and phenylalanine whereas the Opaque-2 corn had sufficient levels. Sihombing 31 31. (1969), Maner 31 31. (1971) and Gipp and Cline (1972) supported Cromwell's work as their research revealed significant increases in average daily gain and feed efficiency with Opaque rations. Wahlstrom 15 and fellow workers' (1973) data showed improved feed ef- ficiency when swine were fed opaque-2 varieties. The average daily gains and feed efficiencies of swine fed either opaque-2 or normal corn will vary depending on the amino acid levels of the corns and actual protein level of the diet. In chicks, opaque-2 corn's superiority was dependent on the availability of lysine and particularly methionine (Rogler, 1966 and Cromwell, 1967). This is not the case with swine. Cromwell 31 311 (1966), Cromwell, Beeson and Pickett (1967) and Drews 31 31. (1969) showed that levels of tryptophan affected the performance of opaque-2 and normal corns. Lysine addition to swine ra- tions did not result in performance data equal to that of lysine and tryptophan supplementation. This evidence sug- gests that the amino acid tryptophan may have a more limiting effect on swine corn rations than lysine. Welch _1 _1. (1966) discovered that N retention was ssignificantly increased in swine fed lysine and tryptOphan ssupplements together, but not singly. Cromwell and co- rvorkers (1967) found that normal corn supplemented with lysine and tryptophan gave poorer gains and feed conver- sxions than non-supplemented opaque-2. Klein 31 31. (1972), (lromwell _1 31. (1969) and Marroquin and coworkers (1974) Iurve shown pigs fed 0-2 corn varieties to have increased N 'netention and greater apparent digestible protein. This may be: due to a decline in zein fractions in the high lysine corn Valtieties. Cromwell stated that pigs fed 0—2 retained (P<1.01) greater amounts of nitrogen on an absolute and 16 percent basis than did normal corn when fed to pigs iso- nitrogenously. He also indicated that when fed on an equiva- lent corn protein basis, the swine tended to retain more pro- tein in Opaque rations, thus suggesting that opaque corn would have a superior biological value when compared to nor- mal corn varieties. This greater retention of the absorbed opaque-2 N is most probably due to a superior balance of amino acids in the Opaque-2 mutant. Urinary urea excretion is reduced upon tryptophan ad- dition to either opaque-2 or normal corn rations although the extent of the excretion depression is dependent on the levels of the limiting amino acid. Brown and Cline (1974) found that as the dietary amino acid balance was improved by supplementing the diet with the first limiting amino acid, the protein synthesized would increase and free plasma amino acid levels would decline. As a result, less non- limiting amino acids would be catabolized to urea and ex- creted. The increase in protein synthesis is the basis for the decline in urinary urea output. Brown's work supports the theory of Almquist (1954) that an amino acid deficiency causes a slow down of protein synthesis and an increase in free amino acids in the plasma. This evidence would sub- stantiate the theory that opaque-2, due to its increased tryptophan and lysine levels, would hasten protein syn- tfliesis and decrease free amino acid plasma levels thus in- creasing N retention and protein utilization in swine. 17 In regard to acceptability, swine tend to consume more opaque-2 than normal corn when fed free choice (Wahlstrom and Libal, 1973). Wahlstrom 31 31. (1973) and Cromwell and coworkers (1969) also reported that swine fed opaque and normal corn rations both supplemented with soybean meal and fed free choice consumed less supplement and more opaque when compared to the normal corn ration. Increased con- sumption of the opaque corn may be the result of better palatibility due to the softer texture of the kernel and the better over-all balance of available amino acids. Abernathy 31 31. (1958) suggeSt that decreased consumption of feed may be due to the build-up of plasma amino acids caused by a limiting amino acid deficiency, thus declining the need for protein and resultant feed intake depression. ' Opaque-2 corn with its higher glutelin and lower zein contents may not be of any real advantage to the ruminant since their rumen microbes synthesize the essential amino acids. It is rather the rate at which the dietary protein constituent is proteolyzed and the N released thus available for microbial utilization that lends its advantages to the ruminant. However, McDonald (1954) and Ely 31_31. (1967) have concluded that 40 to 60% of the zein consumed is digested postruminally since it is not readily susceptible to pro- teolytic breakdown. Research by Beeson, Thomas, Perry and Mohler at Purdue University during 1971, 1972 and 1973 has shown that opaque-2 18 is not superior to normal corn in regards to feeding power in beef cattle. Heifers, on their feeding trials, had equiv- alent daily gains when Opaque-2 was tested against a normal corn hybrid. The feed efficiency of those heifers fed opaque-2 was improved by 8%. Beeson 31 31. (1973) showed data from steers fed opaque-2 that consumed less feed, gained more slowly and had poorer feed efficiencies when contrasted to a normal hybrid corn ration. Nelson 31 31. (1971) found that in their trial with steer calves comparing opaque-2 shelled corn with regular shelled corn, the steers on Opaque-2 produced significantly (P<.01) more efficient gains. However, there was no ap- parent differences in rate of gain. Crossbred steer calves utilized by Goodrich and co- workers (1970) tested the performance of both high lysine and regular corn silages. The feedlot data showed that the rate of gain was similar for both Silages although opaque-2 tended to depress gain. Feed/100 kg gain was slightly less for steers fed Opaque-2. Goodrich 31 31. (1970) also pointed out that cattle fed the normal silage ration tended to eat slightly more feed per day. Two recent studies by Beeson 31 31. (1974) and Goodrich and Meiske (1974) found no difference in the nutritional 'values of Opaque-2 and normal corn for beef cattle. In both trials cattle tended to eat less opaque-2, most likely because of the powdery consistency obtained when rolled. As noted earlier, in ruminants, the value of a ration, in regards to protein value, can be measured by the 19 availability of N to the microbes for microbial protein synthesis. Waxy Corn This hybrid, because of its resemblance to a hard wax both in texture and physical appearance, was suggested by Collins (1909) to be designated cereous or waxy endosperm. It was initially develOped by the Chinese and brought to the United States to replace imported tapioca starch when tapi- oca supplies were reduced due to Japanese invasion of Pacific countries at the outbreak of World War 11. These starches mobilized from the waxy corn were utilized not for livestock feed but rather for adhesives, gum, paper and puddings. It was not until an excess of waxy cereals became prevalent did researchers theorize its possibilities for livestock consumption. Genetically, the waxy trait is the consequence of a recessive gene which controls the percentage and type of starch, either amylose or amlepectin, in the endosperm. Differences in the percent and type of starch found in waxy corn gives it a unique distinction over the conven- tional yellow dent type. Amylose accounts for 25% of yellow dent endosperm and the remaining 75% is amylopectin. Waxy corn is comprised of approximately 100% amlepectin. Amylose is a straight chained molecule that is smaller than amylo- pectin which is branched and wavy (McDonald, 1973). Amylo- pectin has 40 times as many glucose units. 0n chemical 20 analysis, waxy corn was similar in protein and amino acids present, but slightly higher in oil, sugar and weight per volume. Although McDonald (1973) stated that the corns were similar in protein, he also implied that further research need be undertaken concerning protein differences. Higher crude protein values for waxy corn were obtained by Braman 31 31. (1973) and Hanson (1946). Boundy 31 31. (1967) showed waxy corn to have almost two percent less protein. Braman and coworkers (1973) declared that their data portrayed increased protein due to the alco- hol soluble protein zein. The higher zein content was also reflected in the amino acid composition of waxy corn. There is an elevation of leucine, glutamic acid, proline and ala- nine and a decline in lysine as compared to regular dent corn. Boundy 31 31. (1967) indicated lower zein contents and thus lower glutamic acid, proline, alanine and leucine levels. However, in the literature reviewed, Boundy and workers are the only indicators of a decreased zein level in waxy corn. The evidence seems to point toward increased zein levels in waxy corn even though the protein is not very high in quality. More research to determine actual protein composition, i.e. amino acids, is required before any deductions can be made as to whether protein content or starch type affects average daily gain and feed to gain ratios. 21 In a feeding trial with rats, Robinson 31 31. (1974) compared waxy and regular corn in respect to average daily gain and feed to gain ratio. The waxy diet boosted ADG by 8% and gain/feed by approximately 13%. This ration con- tained 15% protein. If the percent protein were raised to 25%, the dent corn was superior in ADG by almost 20% and a mere 2% in feed efficiency. This would suggest that there was a protein threshold where upon once reached, waxy corn metabolism becomes inferior to that of dent in rats. Data from research by Braman 31 31. (1973) indicate that feeding lambs waxy corn increases ADG (P<.01), gain/feed (P<.01) and plasma urea-nitrogen concentration (P<.01) when compared to dent corn. Coupled with these increases were decreases in fecal N (P<.01) and retention of absorbed N (P<.01) although corn type had no effect on nitrogen intake retained. Apparent N digestibilities in waxy corn were higher (P<.10) even though dry matter digestibilities were not significantly different between the two corns. This elevated nitrogen digestibility was reflected in the de- creased fecal nitrogen losses (P<.10). However, the ap- parent N digestibilities were also associated with signifi- cant (P<.01) increases of urinary nitrogen excretion. Con- sequently, retention of absorbed nitrogen was higher (P<.10) with a yellow dent corn diet. In a similar experiment also conducted by Braman, Hatfield, Owens and Rincker (1973), lambs were fed waxy or dent corn supplemented with soybean meal or urea. Of these two diets, 22 regular corn supplemented with urea caused urinary nitrogen excretion to increase markedly (P<.01). McDonald (1954), as a result 0f experimentation, pr0posed that waxy corn, with a higher zein level, would be somewhat more resistant to pro- teolytic enzyme attack in the rumen. Consequently, less ruminal ammonia would be produced. Braman, in his Ph.D. thesis, stated that lambs on a waxy corn diet had a more active rumen fermentation. This fact would increase nitro- gen requirements of the microflora and a supplement such as urea should be added to the ration. This addition of NPN would intensify microbial protein synthesis and as a final result increase body tissue growth and maintenance. An improved quantity of amino acids from microbial sources would enhance retention of nitrogen and thus amino acid breakdown and excretion of urea-nitrogen would decline (Braman, 1973). Braman theorizes that the significant differences in average daily gain and feed efficiency (P<.05) in those lambs fed waxy corn were due to increased microbial end products, i.e. amino acids, protein, cells and the resulting energy reten- ion. A nitrogen balance trial with 20 lambs by Robinson 31 31. (1974) failed to depict any significant differences when the animals were on a 16% protein diet. Mussehl 31 31. (1944) discovered that waxy corn was equiv- ' alent to yellow dent or slightly superior, although not signi- ficant, in its usage in poultry diets. Work done by Kent Feeds Research Farms in 1973 with laying hens showed a 5% decline in egg production when fed a 16% soybean meal, waxy 23 corn ration. Hanson 31 31. in 1946 conducted the first swine trials comparing regular corn to waxy known to this author. A cereal named Nebraska waxy was utilized in the experiment which was comprised of 88 pigs. The corn was a hybrid, a cross of the original strain brought from Asia with two standard varieties of regular corn. 'Hanson's research showed no significant differences in gain or feed effi- ciencies. In one trial however, the pigs were given a choice of feed; either waxy or regular corn. They consumed 2.6 times as much non-waxy corn than waxy. Nevertheless, the trial deductions were not altered. The reason for the differences in type of corn consumed was not known. Trials conducted at the University of Nebraska (1973) and the University of Kentucky (1973) showed no significant divergencies in swine trials when fed waxy corn. According to McDonald (1973), Kent Feeds of Iowa did show an improvement in average daily gain and feed effi- ciency. Pigs fed waxy corn gained 2.1% faster and their efficiency was 4.0% better than their regular corn counter- parts. The feed efficiency difference occurred during the last 77 days which could infer that the growing and fin- ishing phases had dissimilar effects. The earliest published beef cattle trials with waxy corn were conducted by Braman 31 31. in 1973. Waxy corn supple- mented with soybean meal was superior (P<.05) to other non- waxy corn diets. There was no difference in feed efficiencies, 24 although feed consumption tended to be higher with a waxy diet supplemented with soybean meal. Carcass data were similar among treatments. Robinson, Hatfield and Hixon (1974) conducted a feedlot trial with 180 yearling Holstein steers. They found no significant dissimilarities either in corn type effects or level of protein. Similar trials with 124 heifer calves were performed without differences. Braman 31 31. in 1973, conducted a trial with steers supplementing the corns with soybean meal or a soybean meal- urea mixture. Reports contrary to his trials with sheep were obtained. Steers fed soybean meal had greater gains and a little improvement in feed efficiencies. Urea-soybean supplements seemed to have a detrimental effect on gain and feed ratios. Braman gives two reasons for the reverse data between lambs and steers. First, feed intake was restricted in the sheep trials but the steers were fed 33 libitum. There could possibly be a palatability problem concerning the urea with the steer trial, thus accounting for the depressed results. Secondly, the degree of nitrogen di- gested and recycled to the rumen may differ from animal to animal. Other beef cattle trials were performed by Kent Feeds of Iowa, under the auspices of McDonald 31 31. (1973). His results depicted a 10% increase in average daily gain and a 9.5% positive response in feed efficiency when the beef cattle were on a waxy corn diet. These responses were 25 highly significant (P<.025). In this experiment, NPN was added and the ration fed 33 libitum. However, the above results should not be termed conclusive, since another trial utilizing a different corn cr0p showed only a . % increase in average daily gain and a 4.7% increase in feed effi- ciency.‘ Both increases were not significant. McDonald offers no reason for this turn about in statistical data, regardless of the fact that both formulated rations were identical as to percent protein, type of protein supplement employed and the ratio of corn to supplement fed. This author can only theorize that the waxy corn itself differed from trial to trial in protein and starch content. Both of McDonald's trials (1973) showed a slight decline in the daily feed intake of the waxy diet compared to the dent. No differences were observed in carcass character- istics. Kent Feeds also reported that waxy corn increased ni- trogen balance and nitrogen retention by 18 and 17% respec- tively. These figures may be disputed however since the waxy corn used was a mixture of genetic and environmental backgrounds. McDonald did not go into any further detail concerning these data. MATERIALS AND METHODS In this study, three experiments were performed: a feeding trial with steers, a feeding trial with swine and a metabolic trial concerning nitrogen retention and energy- utilization in swine. EXPERIMENT I - Steer Feeding Trial A - Design A 3x3 factorial design was employed to compare average daily gains and feed per pound gain ratios with different combinations of sixty percent silage and forty percent high moisture, rolled corn rations on a dry matter basis. The experimental design is portrayed by Table l. B - Silage Harvest All corns utilized for silage were planted between May 18, 1973 and May 21, 1973. The three corns, sowed from three lots of six, fifty pound bags, had the following pedigrees: Opaque, A61902 x A63202; yellow dent, A619 x A632 and waxy, WX 43619 x A632. Each lot was well isolated from any other lot to prevent contamination by cross- pollination. 26 27 wofipmm pom xww pom woenmcoo Houpme zsw no memo OOHAOQ houmw unmfioz ommho>m no OOH umnu how :fiwm xaflmw owmho>m hm .E.Q .2.Q , IIIII1|II .Z.Q .z.< .z.< 111111 .z.< swag 11111.0.m.< 11111.0.m.< c 11111 .u.m.< m .2.9 .z.o .11111 .z.a .z.< .z.< 11111. .2.< N-m:emao 11111.u.a.< 11111.0.o.< m 11111 .o.m.< N .2.n .2.a HHHHH 503.2.o .z.< .3.< .11111 flnv.2.< puma onHo> .o.a.< .o.a.< a hav.o.m.< H >x-(/~lt\)l--‘| 55 TABLE 12 COMPARISON OF FINISHER RATION AMINO AC1 PERCENTAGES TO RECOMMENDED PERCENTAGES Amino Acids D.D.2 H.M.D.3 H.M.O-z4 H.M.w.5 N.R.C.6 Arginine .82 .82 .96 .84 .16 Histidine .29 .32 .33 .34 .15 Isoleucine .64 .62 .62 .63 .41 Leucine 1.28 1.48 1.29 1.57 .48 Lysine .52 .58 .69 .59 .57 Met.& Cys. .33 .40 .39 .39 .41 Phe. 8 Tyr. .93 1.21 1.19 1.24 .41 Threonine .54 .50 .58 .52 .37 Valine .62 .73 .76 .75 .41 ; Percent of diet on a dry corn basis 3 Dry dent 4 High moisture dent 5 High moisture opaque-2 6 High moisture waxy National Research Council, Nutrient Requirements of Swine, National Academy of Sciences 56 TABLE 13 CARCASS DATA Item D1y Dent H.M. Dent H.M. 0-2 H.M. Waxy t SE1 % Dress 73.2 71.8 74.5 73.1 1.15 % Ham 5 Loin 42.1 40.8 40.9 39.6 1.14 1 standard error of the mean 57 still above the recommended minimum, but perhaps the de- cline in average daily gain could convey that the recom- mended levels stated by the N.R.C. (1973) were too low for maximum performance in the finisher phase. No significant carcass data differences were obtained upon slaughter (Table 13). ’This was the general case with all research reports reviewed. EXPERIMENT III - Balance Trial Feeds used for the balance trial were from the grower phase of Experiment II and therefore had identical amino acid levels and protein percentages. No significant dif- ferences were obtained concerning the nitrogen balance, dry matter balance or energy balance studies (see Table 14). In the dry matter study there seems to be a similarity among the dry dent, H.M. 0-2 and H.M. dent corns. The waxy corn consumption seems depressed possibly as a result of its flaky texture. Apparent dry matter digestibilities are not dissimilar. In the energy trial, digestible energy percents do not differ significantly nor do the metabolizable energy per- centages. This trial would seem to portray that of the corns used, 110 one corn ration was significantly superior to any other in the nitrogen, dry matter or energy balance studies. 58 TABLE 14 SUMMARY OF BALANCE STUDY Dry H. . H.M. H.M. Item Dent Dent Op3que-2 Waxy tSEl N balancez’3 N intake, g 42.70 35.76 37.67 39.43 5.43 Fecal N, g 7.29 5.84 6.44 5.90 1.10 Absorbed N, % 82.78 83.67 82.90 85.04 1.59 Urinary N, g 8.31 5.54 8.84 6.67 1.46 N retention, g 27.10 24.38 22.39 26.86 3.58 N retention, % 64.46 68.24 59.11 68.52 3.26 Biological Value App. 76.50 81.60 71.70 80.10 ---- Dry matter balance?"4 D.M. intake, g 1566 1072 1237 997 ---- Fecal D.M., g 299 168 201 166 ---- Fecal D.M., % 32 27 28 30 ---- D.M. app dig , % 68.0 73.0 72.0 70.0 ---- Energy balancezi4 Energy intake, kca15 6097 4219 4945 3817 564 Fecal energy, kcal 1250 761 909 758 179 Urinary energy, kcal 56 44 65 56 9.9 Digestible energy, kca16 4847 3458 4036 3059 404 Energy digested, % 79.5 81.9 81.6 80.1 2.3 Metabolizable energy, kcal 4791 3414 3971 3003 400 Energy metabolized,% 78.6 80.9 80.3 78.7 2.2 N-corrected ME, kcal 4608 3249 . 3853 2821 385 N-corrected ME, % 8 75.6 77.0 77.9 73.9 2.1 OOVO‘W-RWNH' standard error of the mean based on per pig/day mean values as fed basis means D.M. basis means Gross energy, kcal/kg= 3895,3936,3997,3828, respectively DE, kcal/kg= 3097,3226,3262,3068, respectively ME, kcal/kg= 3061,3210,3l85 3011, respectively N-corr. ME, kcal/kg= 2878,3020,3092,2829, respectively GENERAL CONCLUSIONS The results of the three experiments have led the author to make the following conclusions: 1. In beef cattle, opaque-2, waxy and yellow dent corns support similar performance. Increased lysine may have no nutritional value to the ruminant since amino acid synthesis occurs in the rumen by microbial processes. The only way in which opaque-2 corn is advantageous to beef cattlemen is through yields per acre which are equal to or superior to that of dent corn. In this case the yield was lower. Opaque-2 corn could possibly be of some value to swine producers as long as the protein level does not fall below that of regular corn. Waxy corn did not significantly improve cattle per- formance although there was a tendency to do 50. Its yields were equal to that of 0-2 corn and less than dent corn in this trial. Waxy corn rations tended to depress swine performance probably due to its decreased lysine and increased zein. Tryptophan levels should have been analyzed. There was no real difference among corns concerning nitrogen retention, dry matter digestion and energy retention by swine. 59 BI BLI OGRAPHY BIBLIOGRAPHY Abernathy, R. P., R. F. Sewell and R. L. Tarpley. 1958. Interrelationships of protein, lysine and energy in diets for growing swine. J. Anim. Sci. 17:635. Almquist, H. J. 1954. Utilization of amino acids by chicks. Arch. Biochem. 52:197. Baker, D. H. 1973. Amino acid nutrition of swine and poul- try. Proceedings of the Georgia Nutrition Conference. p. 11. Barker, S. B. and N. H. Summerson. 1941. The colorimetric determination of lactic acid in biological material. J. Biol.Chem. 138:535. Beeson, W. M. and T. W. Perry. 1958. Comparative feeding value of high moisture corn and low moisture corn with different feed additives for fattening beef cattle. J. Anim. Sci. 17:368. Beeson, W. M., R. A. Pickett, E. T. Mertz, G. L. Cromwell and 0. E. Nelson. 1966. Nutritive value of high lysine corn. Proc. Distillers Res. Conf. Cincinnati, Ohio. p. 70. Beeson, W. M., T. W. Perry, V. M. Thomas and M. T. Mohler. 1973. Raw vs. Opaque-2 vs. roasted corn and regular vs. opaque-2 corn silage for finishing beef cattle. Indiana Res. Rep. .Beeson, W. M., V. M. Thomas, T. W. Perry and M. T. Mohler. 1974. The nutritional value of regular, Opaque-2 and waxy corn for finishing beef cattle. Indiana Res. Rep. IBergen, W. G. and E. L. Potter. 1971. e-N-methyl lysine metabolism in sheep. J. Anim. Sci. 32:1245. 130thast, R. J., G. H. Adams, E. E. Hatfield and E. B. Lancaster. 1974. Preservation of high moisture corn. J. Anim. Sci. 39:193. (Abstr.). IBoundy, J. A., J. H. Woychik, R. J. Dimler and J. S. Wall. 1967. -Protein composition of dent, waxy and high amylose corns. Cereal Chem. 44:161. 60 61 Bramen, W. L., E. E. Hatfield, F. N. Owens and J. D. Rincker. 1973. Waxy corn and N Sources for finishing lambs and steers fed all concentrate rations. J. Anim. Sci. 37: 1010. Brookes, I. M., M. L. Hershbarger and R. W. Henderson. 1969. Opaque-2, higher-oil, higher-protein and regular corn in diets for growing lambs. J. Anim. Sci. 28:103. Brown, J. A. and T. R. Cline. 1974. Urea excretion in the pig: an indicator of protein quality and amino acid requirements. J. Nutr. 104:542. Burkhardt, J. D., L. B. Embry and R. M. Luther. 1969. Corn processing methods for high concentrate diets. J. Anim. Sci. 29:153. (Abstr.). (Zlark, J. H. and K. E. Harshbarger. 1972. High moisture corn vs. dry corn in combination with either corn silage or hay on lactating cows. J. Dairy Sci. 55:1474. (Collins, G. N. 1909. A new type of Indian corn from China. U.S.D.A. Bur. Plant. Ind. Bul. 161. (3romwell, G. L., J. C. Rogler, W. R. Featherston and R. A. Pickett. 1966. Nutritional value of opaque-2 corn for the chick. Poultry Sci. 46:705. Chomwell, G. L., R. A. Pickett and W. M. Beeson. 1967. Nutritional value of opaque-2 corn for swine. J. Anim. Sci. 26:1325. Cromwell, G. L., R. A. Pickett, T. R. Cline and W. M. Beeson. 1969. Nitrogen balance and~growth studies of pigs with Opaque-2 and normal corn. J. Anim. Sci. 28:478. lDrews, J. E., N. W. Moody, V. W. Hays, V. C. Speer and R. C. Ewan. 1969. Nutritional value of Opaque-2 corn for young chicks and pigs. J. Nutr. 97:537. IDuncan, D. B. 1955. Multiple range and multiple "f" tests. Biometrics. 11:1. lily, D. G., C. 0. Little, P. G. Woolfolk and G. E. Mitchell, Jr. 1967. Estimation of the extent of conversion of dietary zein to microbial protein in the rumen of lambs. J. Nutr. 91:314. IEeatherston, W. R. and E. L. Stephenson. 1960. Dietary interrelations between methionine, glycine, choline, protein levels and energy content of the chick diet. Poultry Sci. 39:1023. 62 Florence, H. D., J. R. Riggs and G. D. Potter. 1968. Phys- ical characteristics of reconstituted sorghum grain. J. Anim. Sci. 27:1163. (Abstr.). Forsyth, J. G., J. B. Stone and D. N. Mowat. 1970. Propi- onic acid preserved corn in cattle rations. J. Anim. Sci. 31:1038. (Abstr.). Gipp, W. F. 1968. Nutritional evaluation of opaque-2 and floury-Z corns for non-ruminant animals. M.S. Thesis. Purdue Univ. Lafayette, Indiana. Gipp, W. F. and T. R. Cline. 1972. Nutritional studies with Opaque-2 and high protein opaque-2 corn. J. Anim. Sci. 34:963. Goodrich, R. D., F. H. Gharib and J. C. Meiske. 1970. The value of high lysine and conventional corn silage for growing steers. Minnesota Res. Rep. Goodrich, R. D. and J. C. Meiske. 1974. Comparison of four types of corn. Minnesota Res. Rep. iHanson, L. E. 1946. Waxy corn vs. non-waxy corn for growing fattening pigs in dry lot. J. Anim. Sci. 5:36. Heuberger, G. I., G. E. Mitchell, Jr., W. W. Albert and A. L. Neuman. 1959. The effect of moisture content of field shelled corn on harvesting and storage losses and on its feeding value for beef cattle. J. Anim. Sci. 18:1527. (Abstr.). Klein, R. G., W. M. Beeson, T. R. Cline and B. T. Mertz. 1971. Opaque-2 and floury-Z corn studies with growing swine. J. Anim. Sci. 32:256. Klein, R. G., W. M. Beeson, T. R. Cline and B. T. Mertz. 1972. Lysine availability of opaque-2 corn for rats. J. Anim. Sci. 35:551. Igong, T. A. 1973. Acid treating grains and forages. Pennsylvania State Univ. Rep. AS-BC-73-1. ILynch, P. B., D. H. Baker, B. G. Harmon and A. H. Jensen. 1974. Chemically treated high moisture corn in diets for swine. 66th National Meeting Amer. Soc. Anim. Sci. p. 185. (Abstr.). Ddaner, J. H. 1971. Performance of rats and swine fed Columbian floury-Z, Columbian Opaque-2 or normal corn. J. Anim. Sci. 33:791. 63 Marroquin, C. R., G. L. Cromwell and V. M. Hays. 1974. Nutritional value of several varieties of opaque—2 and normal corn for growing swine. J. Anim. Sci. 36:253. McDonald, I. W. 1954. The extent of conversion of food pro- tein to microbial protein in the rumen of sheep. Biochem. J. 56:120. McDonald, T. A. 1973. Waxy corn feeding trial results. Kent Feeds of Iowa. Muscatine, Iowa. Mimeo. Rep. McDonald, T. A. and G. A. Mente. 1973. Waxy corn and source of protein for finishing steers. J. Anim. Sci. 37:350. bchnight, D. R., G. K. MaCleod, J. G. Buchanan-Smith and D. N. Mowat. 1973. Utilization of ensiled or acid treated high moisture shelled corn by cattle. Can. J. Anim. Sci. 53:491. bcharen, R. J. and J. K. Matsushima. 1968. Digestion of ensiled reconstituted corn. J. Anim. Sci. 27:1170. (Abstr.). Pdeisinger, D. J., G. H. Kroening and H. H. Hodson, Jr. 1974. High moisture acid treated corn for weanling pigs. J. Anim. Sci. 39:186. (Abstr.). rflertz, E. T., L. S. Bates and O. E. Nelson. 1964. Mutant gene that changes protein composition and increases lysine content of maize endosperm. Science. 145:279. Imertz, E. T., O. A. Veron, L. S. Bates and O. E. Nelson. 1965. Growth of rats fed on opaque-2 maize. Science. 148:1741. IMertz, E. T. 1966. Growth of rats on opaque-2 maize. Proc. High-Lysine Corn Conf. Corn Industry-Research Founda- tion, Inc., 1001 Conn. Ave., Washington, D. C. p. 19. Ddiller, J. I., J. B. Robertson and R. Logan. 1969. Acid preservation of high moisture corn for beef cattle. Mimeo. Report. Cornell Univ., Ithaca, N. Y. Bailler, J. I., J. B. Robertson and R. Logan. 1972. Preser- vation of high moisture corn with propionic acid. Mimeo. Report. Cornell Univ., Ithaca, N. Y. Ddiller, J. I. and R. Logan. 1972. Summer storage and feeding of high moisture shelled corn preserved with propionic acid or a mixture of acetic-propionic acid. Mimeo. Rep. Cornell Univ., Ithaca, N. Y. 64 Mussehl, F. E. 1944. .Growth promoting value for chicks of waxy corn. Nebr. Agr. Exp. Sta. Ann. Rep. 57. p. 79. National Research Council. 1960. Nutrient requirements of domestic animals, No. 1 - Nutrient requirements of poultry. Pub. 827. National Acad. Sci. N.R.C. Washington, D. C. National Research Council. 1964. Nutrient requirements of domestic animals, No. 1 - Nutrient requirements of swine. Pub. 1192. National Acad. Sci. N.R.C. Washington, D. C. National Research Council. 1973. Nutrient requirements of domestic animals, No. 2 - Nutrient requirements of swine. National Acad. Sci. N.R.C. Washington, D. C. Nelson, L. F., R. 1. Pick and F. Diaz. 1971. Normal and opaque-2 corn for feeding steers. J. Anim. Sci. 33: 1168. (Abstr.). Osborne, T. B. and L. B. Mendel. 1914. Amino acids in nutrition and growth. J. Biol. Chem. 7:325. Pickett, R. 1966. Opaque corn in swine nutrition. Proc. High-Lysine Corn Conf. Corn Industry-Research Founda- tion, Inc., 1001 Conn. Ave., Washington, D. C. p. 19. Polzin, H. W., D. E. Otterby, J. M. Murphy and D. G. Johnson. 1972. Utilization of ensiled, acid treated and dry corn by lambs. J. Anim. Sci. 35:1133. (Abstr.). Robinson, G. N., E. E. Hatfield and D. L. Hixon. 1974. Waxy Corn as a dietary ingredient. 66th Amer. Soc. of Anim. Sci. p. 251. (Abstr.). Rogler, J. C. 1966. Comparison of opaque-2 and normal corn for chicks. Proc. High-Lysine Corn Conf. Corn Industry- Research Foundation, Inc., 1001 Conn. Ave., Washington, D. C. p. 23. Sihombing, D. T. H., G. L. Cromwell and V. W. Hays. 1969. Nutritional value and digestion of opaque-2 and normal corn for growing pigs. J. Anim. Sci. 29:921. 'Tonroy, B. R., T. W. Perry and W. M. Beeson. 1974. Dry, ensiled high moisture, ensiled reconstituted high mois- ture and VFA treated high moisture corn for growing- finishing beef cattle. J. Anim. Sci. 39:931. ‘Veum, T. L., W. H. Pfander, C. G. Bellamy and H. B. Hedrick. 1974. Opaque-2 and normal corn as amino acid sources for barrows and gilts. J. Anim. Sci. 36:877. 65 Wahlstrom, R. C. and G- W. Libal. 1973. Performance of swine fed opaque-2 or normal corn free choice. J. Anim. Sci. 36:898. Welch, J. G., R. H. Cordts and G. W. Vander Noot. 1966. Effect of lysine, methionine and tryptophan supplementa— tion upon N retention of barrows. J. Anim. Sci. 25:806. APPENDIX 66 TABLE A—l ACTUAL FEED VALUES PER BODY WEIGHT Average Weight Corn Silage Shelled Corn 204 —--------------4- 54 --_---------_---- 16 211 ------__-----_--- 56 --------------__- 17 218 -------_---_----- 58 ---------------_- 17 225 ---------------- —- 60 -—--—-~---------- 18 232 -------------- ---- 62 -—----~-—-------- 19 238 ----------------- ~-- 63 --------- a -------- 19 245 ----------------- 65 -- ----- .- ----- ----- 20 252 ------- ~ ---------- 67 -----‘ ----- - ------ 20 259 ----------------- 69 ----------------- 21 265 --- -------------- 2 71 ---- ------ < ------- 22 272 -------------‘--- 73 -------------- 4--- 22 279 ----------------- - 74 -------- --------- 23 286 ---- -------------- 76 ----------------- 23 293 -------------- 5--- 78 ----------------- 24 299 --------------- --- 80 ----------------- 24 306 ------ , ----------- 82 -------- . ----- - ------ 24 313 -_-.-.----'_.--.-.---.--. 84 ----.-.--.-----_---- 25 320 -------------- ---« 85 -------- - ------ ---- 25 327 ----------------- 87 ----------------- 26 333 —--- ------- '-~--~- 89 —------~—~------- 27 340 --------- ~ ----- --——- 91 «—-------------—- 27 347 -‘--—- ------------- 93 ---5- -------- ----- 28 354 ------- »—--------— 95 -‘ ----------- ~-—-- 28 361 --_-----1-------- 96 ....... . ............. . 29 367 ----~---------‘-- 98 -------------- ---- 29 374 --—-—-~------~-— 100 —--—------------- 30 381 ------------------- - 102 ------- -~ ---------- 30 388 ---------------- 104 ------------------ 31 395 ----------------- 106 ----------------- 32 401 ---------------- - 107 ----------------- 32 408 ---------------- 109 ----------------- 33 415 ---------------- 111 ----------------- 33 422 ----------------- 113 ----------------- 34 429 ---------------- 115 ----------------- 34 435 ---------------- 117 ----------------- 35 442 ---------------- 118 ----------------- 35 449 ---------------- 120 ----------------- 36 456 ---------------- 122 ----------------- 36 463 ----------------- - 124 ----------------- 37 469 ------------ --—-- 126 --- -------------- 38 476 --—~—--—-------- 127 ---—~-—-~-------- 38 1 all weights in kilograms FEED ANALYSIS OF SILAGES AND CORNS TABLE A-Z 67 SILAGES. Item Dent Opaque-2 Waxy D.M., % 36.55 38.11 33.27 pH 4.12 4.09 4.09 Total N, % 1.97 2.03 2.21 Crude protein, % (DM) 12.31 12.69 13.81 Lactic Acid, % 8.87 8.62 9.26 Acetic Acid, % 1.05 1.29 1.02 Butyric Acid, % .12 .11 .13 SHELLED CORN Item Dent Opaque-2 Waxy D.M., % 79.48 79.02 74.19 pH 4.51 4.58 4.43 Lactic Acid, % .23 .26 .24 Total N, % 1.66 1.76 1.75 Crude protein, % (DM) 10.36 11.00 10.95