EFFECTS OF MARGINAL VITAMEN A INTAKE DURING GESTATiON EN SWENE Thais fur tho Damn-o of Ph. D. WEN-IGAN STATE UNIVERSITY David Paul Hsaney E950 This is to certify that the thesis entitled EFFECTS OF MARGINAL VITAMIN A INTAKE DURING GESTATION IN SWINE presented by DAVID PAUL HEANEY has been accepted towards fulfillment of the requirements for Ph.D. Animal Husbandry degree in—— (Nutrition) 0 4‘ wt LA. 2 Majorgrofessor Date—043m 0—169 LIBRARY University Michigan State > J i i EFFECTS OF MARGINAL VITAMIN A INTAKE DURING GESTATION IN SHINE By DAVID PAUL BEANEY AN ABSTRACT Submitted to the School for Advanced Graduate Studies of Hichipn State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR. OF PHILOSOPHY Department of Animal Husbandry 1960 Approved 31, dc NJ» // D . w.,—.V , .‘a-F M 7.5 "‘ p. . ‘5) _,_—_. . -aar { ~ 5.35." D. P. Heaney ABSTRACT Fifteen gilts, making 3 experimental groups of 5 gilts each, were used to study the effects of a marginal level of dietary vitamin A during gestation. The experiment was begun when the gilts were approximately 4 months of age and continued through 2 complete gestation periods. The 5 control gilts were allowed an adequate level of vitamin A throughout the experiment. The 10 gilts of the other 2 experimental groups were first depleted of vitamin A reserves. then allowed graded levels of vit- amin A during the gestation periods. The basic ration used throughout the experiment was a low vitamin A ration based on oats and wheat with soybean meal and meat and bone scraps providing protein, and supplemented with minerals and vitamins with the exception of vitamin A. Good results were achieved with this depletion ration and no difficulty was encountered in reducing the plasma vitamin A levels to the desired values of 10 micrograms or less per 100 m1 of plasma. During the 2 gestation phases of the experiment the gilts were in- dividually fed twice a day. The individual daily doses of vitamin A were added to the morning feed of each gilt. The levels of supplemental vit- amin A fed to the 3 experimental groups were as follows: (1) Group I (Control). 16 micrograms of vitamin A per kilogram body weight daily; (2) Group II. 5 micrograms of vitamin A per kilogram body weight daily; and (3) Group III, 2.5 micrograms of vitamin A per kilogram body weight daily. Periodic blood samples were taken from the gilts throughout the D. P. Heaney trial and were analyzed for vitamin A content. At parturition colostrum 6amPlea were taken from the gilts and blood samples were taken from the newborn pigs before they had nursed. Half of each litter was then sacri- ficed and the livers taken. Additional milk samples, and blood samples from the surviving baby pigs, were taken at 2h hours, 72 hours and 168 hours post-partum. These various blood, liver and milk samples were also analyzed for vitamin A content. A dietary intake of 3 to 3.5 micrograms of vitamin A (supplemental vitamin A plus content of basic ration) per kilogram body weight was suf- ficient to meet the daily requirements of the dams themselves. This level of dietary vitamin A was sufficient to restore plasma vitamin A values, prevent deficiency symptoms. and maintain the gilts in good health. This low dietary intake did not seem adequate for optimum reproduction or liver storage. The data, while not conclusive, indicated that 5 to 6 micrograms of dietary vitamin A daily per kilogram body weight is needed for repro- duction. The baby pigs at birth were all healthy, vigorous and strong with the exception of half the pigs in one of the litters in group III. There were no differences in birth rate, gains after birth, or survival rates which could be attributed to lack of vitamin A. Likewise, there were no visible, gross abnormalities which could be definitely attributed to lack ‘ of vitamin A. There were significant differences among the 3 experimental groups in both the liver vitamin A reserves, and plasma vitamin A levels, of the baby pigs at birth. The livers of the newborn pigs in group III contained little, if any, vitamin A. The plasma vitamin A levels at birth of 2 lit- ters of this group were bordering upon deficiency levels. After the D. P. Heaney ‘Lfigestion of colostrum, however. the plasma vitamin A values increased markedly and thereafter stayed in the normal range. The colostrum vitamin A levels were much higher than those of later milk in all of the experimental groups. During the first 24 to 72 hours post-partum there was a consistent, rapid decline in milk vitamin A con— tent followed by a tendency for the milk vitamin A levels to stabilize. At each of the sampling periods, the colostrum and milk vitamin A levels of the control group were significantly higher than those of the other 2 youps. There were no apparent differences in milk or colostrum vit— amin A between groups II and III. EFFECTS OF MARGINAL VITAMIN A INTAKE DURING GESTATION IN SWINE By DAVID PAUL KEANE! A THESIS Submitted to the School for Advanced Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Animal Husbandry 1960 Approved 9.4 '74er fl ‘6 ACKNOWLEDGEMENTS The author wishes to express his sincere appreciation to Dr. J. A. Hoefer for his invaluable guidance and assistance throughout this study. Appreciation is also extended to Dr. J. A. Hoefer and Dr. D. E. Ullrey for their critical reading of the manuscript. Thanks are also expressed to Dr. D. E. Ullrey for his counsel and assistance in the laboratory work, and to he and Dr. E. R. Miller for their instructions in the bleeding technique and aid in the collection of samples. The author wishes to thank the herdsman, Mr. G. B. Stafford and his staff, for their assistance in the care and management of the pigs, and in the collection of the samples. Gratitude is expressed to Dr. J. E. Nellor for his critical exam- inations of the reproductive tracts. Sincere gratitude is expressed to Dr. R. H. Nelson, Head of the Department of Animal Husbandry, and to Michigan State University for pro- vision of the facilities and materials necessary to carry out this study, and for financial aid in the form of an assistantship. Thanks are also due to the National Science Foundation for aid in the form of a fellowship. The author wishes especially to express his gratitude and appre- ciation to his wife Jean for her inspiration, patience and encouragement and for her excellent typing of the manuscript. Gratitude is also due to liis wife Jean, and to his son David, for the many sacrifices necessary to make this study possible. Appreciation is extended to Chas. Pfizer and Company for furnishing tlie stabilized vitamin A palmitate. David P. Heaney candidate for the degree of Doctor of Philosophy DISSERTATION: Effects of Marginal Vitamin A Intake During Gestation in Swine OUTLINE OF STUDIES: Major area of study: Animal Husbandry (Animal Nutrition) Supporting areas of study: Biochemistry, Physiology BIOGRAPHICAL ITEMS: Born: December 25, 1927, Choteau Montana Undergraduate studies: Montana State College, l9#7-l951 Graduate studies: Montana State College, 195h-1956 Cambridge University, England, 1956-1957 Michigan State University, 1957-1960 EXPERIHICE: Member United States Air Force, 1951-1953 Graduate Assistant, Montana State College, 199M956 Graduate Assistant, Michigan State University, 1957-1959 MEMBER: American Society of Animal Production Society of Sigma Xi (Associate member) TABLE OF CONTENTS INTRODUCTION. 0 O O O O O O O O O O O O O O O O O O O O O O O O O O 0 LITERATURE REVIEW. . . . . . . . . . . . . . . . PMflDummYSflmL ... ... ... ... ... PROCEDURE.................... General. . . . . . . . . . . ._. . . . . . . Depletion Period. . . . . . . . . . . . . . Gestation Phase. . . . . . . . . . . . . . . Collection of Data. . . . . . . . . . . . . RESULTS AND DISCUSSION. . . . . . . . . . . . . . Depletion Period and Sows' Vitamin A Status. Fertility. . . . .'. . . . . . . . . . . . . Litter Performance. . . . . . . . . . . . . Milk Vitamin A Content. . . . . . . . . . . Liver Vitamin A Reserves of the Newborn Pig. Baby Pig Blood Plasma Vitamin A Levels. . . CONCLUSIONS. . . . . . . . . . . . . . . . . . . SUMMARY. . . . . . . . . . . . . . . . . . . . . LITERATURE CITED. . . . . . . . . . . . . . . . . APPmDIX O O O O O O 0 O O O O O O O O O O O O O O I O O O O O O O O O O O O I O O O O 1 z. 22 2A 2A 27 29 33 36 36 1.1, 52 57 61 6h 70 72 7 5 83 LIST OF TABLES are: 1. Litter data for the gilts. . . . . . . . . . . . . . . 2. Basic ration-ingredients and formulation . . . . . . 2a. Basic ration-- composition and N. R. C. recommendations 3. Treatment group and identification of the gilts. . . . A. Representative live weights for the gilts. . . . . . . 5. Representative plasma vitamin A levels of the-gilts. . 6. Liver vitamin A content for the gilts. . . . . . . . . 7. Breeding performance . . . . . . . . . . . . . . . . . 8. Litter performance: number born, weights at birth and week of age . . . . . . . . . . . . . . . . . . . . . 9. Vitamin A content of milk (mcg./lOO ml). . . . . . . . 10. Liver vitamin A reserves of the newborn pigs . . . . . 11. Plasma vitamin A levels of the first litter baby pigs (mcg./lOO m1). . . . . . . . . . . . . . . . . . . . . 12. Plasma vitamin A levels of the second litter baby pigs (mcg./100 ml). . . . . . . . . . . . . . . . . . . . . 13. Experimental results summarized by treatment groups . 42 46 53 65 66 LIST OF APPENDIX TABLES Table Page 1. Flam Vitamin A Levels Of the Gilts (nc3./100 m1). 0 e e e s e s 83 2. Control Litters: Heights, Liver Vitamin A (mcg./gm.), andplamvj-taminA(mCSe/1mm1) eeeeeeeeeeeeeee 85 3. Group II Litters: Heights, Liver Vitamin A (mcg./gm.). - and?hsmVitaminA(mCSe/1wnl) senses-0000.00.88 A. Group III Litters: Weights, Liver Vitamin A (mcg./gm.), andPhWViminA(mcse/lmml) seeeeeeesseeeee 91 -—- m- ———_—yw.i v “’ ' ‘ ——- , _—.—-—.-j ——__ INTRODUCTION The recognition of fat-soluble vitamin A arose from the failure to secure normal growth in experimental animals kept for long periods of time on purified diets furnishing adequate amounts of the then known dietary necessities. Hopkins in 1906 and Stepp in 1909 had both presented data indicating that certain fat-soluble substances were indispensable for growth in mice and rats. 'By 1913 the existence of growth promoting, 'fat-soluble entities was clearly recognized. In work with rats that appeared almost simultaneously in 1913, McCollum and Davis of Wisconsin, and Osborne and Mendel of Yale, both ascertained the existence of a growth~ factor present in cod liver oil and butterfat, but absent in lard. In 1915 McCollum and Lavis postulated the existence of two factors, fat- soluble A and water-soluble B. Steenbock, in 1919, is generally credited with the discovery of the vitamin A activity of the carotenoids. To explain the apparent incon- sistency of vitamin A activity in colorless as well as in colored compounds, he also advanced the theory that some carotenoid must retain its activity when converted into a hypothetical leuco (colorless) form. Later in 1919 Palmer and Kempster reported that two generations of chickens had been raised on a diet of white corn, white squash, white onions, and small amounts of pig's liver, all of which were virtually devoid of carotenoid pigments. Since no carotenoids were present which could be converted to the hypothetical leuco form, and the true significance of the Supplement of pig's liver was not known, it appeared that Steenbock's theory was -1- incorrect. Thus, although later knowledge showed Steenbock's conclusions to be near the truth, they were not generally accepted for some time. It took a further 10 years of intensive research to clarify the true relationship between carotene and vitamin A. Meanwhile, work was progressing on the chemical nature of vitamin A. By 1931 Karrer had obtained a highly concentrated vitamin A preparation and had determined the structure of the vitamin. In 1933 he and his as— sociates established its chemical nature. In 1937 Kuhn and Morris first announced the synthesis of vitamin A, and Holmes and Corbet obtained vitamin A for the first time in crystalline form. Still, it was another 10 years before substantial quantities of vitamin A were produced in pure form by Arens and Van Dorp and by Isler and co-workers. Carotene, on the other hand, had been known for some time, having been first isolated from carrots by Wachenroder in 1831. The empirical formula was established by Willstatter in 1906. Then, in 1930, Karrer and his associates succeeded in establishing the chemical structure of beta carotene. It was not until 1950 however, that Karrer and associates 1 finally succeeded in its synthesis. These brief historical notes on the discovery of vitamin A and its precursors, and the elucidation of the structures, have been accepted in textbooks on vitamins for many years (see Sherman and Smith, 1931; Rosenberg, 19h5; Moore, 1957). In addition to the work on the chemical structure and properties Of vitamin A, a large amount of research data has accumulated pertaining t<> the biological aspects of the vitamin in various animal species. Vistamin A has been found to be required by all animals for maintenance, EIWDwth, reproduction and milk production. One of its most important - 3 -' functions is to keep the epithelial structures of the body healthy andin proper functioning condition. Vitamin A is also necessary for the for- mation of visual purple which is required for vision in dim light, for the proper functioning of the nervous system and for proper bone growth. The research work that has been conducted with pigs has provided considerable information concerning the vitamin A needs of this species. The vitamin A requirement of the growing pig has been established and confirmed, and the characteristic symptoms in pigs suffering from a lack of vitamin A have been described. Reports in the literature have also enumerated many congenital abnormalities caused by an acute deficiency of vitamin A during gestation. Yet relatively little work has been conducted with pigs to establish the actual gestation requirement of vitamin A, or to determine the effects of the marginal vitamin A intake during gestation which might be encountered under practical conditions. This experiment was initiated to Study these aspects of vitamin A nutrition, and was de- signed with the following objectives in mind: (1) To determine the effects of a sub-optimal intake of vitamin A during gestation upon the reproductive performance of gilts. (2) To determine the effects of a sub-optimal intake of vitamin A during gestation upon baby pigs at birth. (3) To secure an indication of the requirement of vitamin A for reproduction in gilts. Qflmr-s- .- <15 ssn~ ; v r 7— .... L ._‘ ‘<,,_“ v 'WT.’—, ‘ n-v; ._., 3':W J .__.._!m -_ LITERATURE REVIEW In some of the early work published on vitamin A, Orr and Crichton (1921+) were not able to demonstrate the need for vitamin A in growing pigs. They used a diet of wheat bran, crushed oats, blood meal and min— erals. One group of pigs was supplemented with cod liver oil and the other with the same amount of linseed oil and no difference was found between the growth rates of the two groups. In the light of present knowledge their results can probably be explained on the basis of the vitamin A storage of the weanling pigs, plus the fact that while the vitamin A activity of wheat is quite low, it is concentrated in the bran, giving wheat bran a vitamin A activity nearly equal to that of yellow corn (Morrison, 1956). Sherman and McLeod (1925) reported that in rats a diet which con- tained adequate vitamin A for growth was not adequate for reproduction. When no additional vitamin A was given during reproduction the rats either failed to bear young, or the young were born weak and soon died. Sure (1928) reported sterility in rats on vitamin A deficient diets due to resorption during gestation. Mason (1935) was more successful in effec- tively mating deficient ratsand reported results of studies of the effects 01‘ complete or partial deficiency upon gestation. Females deficient in Vitamin A, but which had not reached the stage of developing xerophthalmia, 0ften were successfully mated, though the fetuses usually failed to survive In deficient rats which carried their young to full and were resorbed. term parturition was often delayed and/or delivery difficult. When fetal -14.. -—"I"L. -5- reBOI‘ption occurred, the effects differed from the resorption due to vita— min E. In avitaminosis E the injuries first affected the fetus and were later transferred to the placenta, whereas in avitaminosis A the sequence was reversed. Newton (1938) substantially confirmed Mason's findings. Hughes Q E' (1928) reported data from an experiment in which 8 gilts were fed white corn, tankage and bone ash. Three of the gilts would not breed and the remaining 5 gilts either aborted about two-thirds through gestation or farrowed dead pigs. Several of the fetuses were partially resorbed. An addition of 10 percent alfalfa meal gave normal reproduction. In a later study Hughes (1931*) reported that on rations based on barley, minerals and casein, gilts either did not come into heat or had irregular estrous cycles without pregnancy. With alfalfa meal or cod liver oil added to the ration normal reproduction was attained. The author attributed the reproductive failure to a deficiency of vitamin A. Hale (1934, 1935) published data~on congenital abnormalities caused by a deficiency of vitamin A in pigs. The same general plan was followed in 3 experiments with 7 gilts over a ‘0 year period. The gilts were first fed a vitamin A deficient ration until they began to show deficiency symp- toms including wobbly gait, crossing of hind legs at a walk, weakness in the back and loss of weight. The gilts would then be bred and left on the vitamin A deficient ration for the first 30 days of gestation, after which they were given adequate vitamin A in cod liver oil. Four of the gilts farrowed litters, in 3 different years, in which the pigs were born with- out eyeballs. A fifth gilt received a 2 ounce dose of cod liver oil 2 weeks before breeding because she had become unable to stand. She far— POVed 10 pigs with various eye abnormalities. Some had no eyes, some one eye, some one large and one small eye, and all were blind. Various GOMbinations of other defects were also observed in the 5 litters, such as subcutaneous cysts, accessory ear-like growths, cleft palates, hare lips and misplaced kidneys. Two gilts failed to farrow, one because of a lack of estrus and the other resorbed her litter. An addition of one percent cod liver oil prevented symptoms in 1? pigs in 2 control litters, while green pasture added to the ration also prevented symptoms. Recently HJarde gt El‘ (1959) have reported similar abnormalities in work conducted in Denmark. Abnormalities present in the newborn pigs from vitamin A deficient gilts included eye defects, accessory ears, cleft palate, subcutaneous cysts, misplaced kidneys, hermaphrodism, hydrocephalus and diaphragmatic hernia. They noted that even such gilts that had no detectable vitamin A in the liver had apparently normal heat symptoms and estrous cycles. However, the rate of infertile services was high. Guilbert gt El. (1935, 193?, 1940) did much of the early work that established the minimum requirements of farm animals. Their work was based upon nightblindness as a criterion supplemented by checks on storage. Evidence was presented which indicated that the amounts of vitamin A or carotene that just prevented nightblindness represented a physiological minimum. Based on this criterion their stated requirements for cattle, sheep, swine and horses all fell within the same relative ranges. The ntinimum carotene requirement was found to be 25-35 micrograms per kilogram 13f body weight daily, and the minimum vitamin A requirement was found to be 5-8 micrograms per kilogram of body weight daily. Ehtcellentv growth said recovery from symptoms occurred at these levels yet storage after extended periods was meager. Studies of storage at different levels of illtame indicated that levels of at least 3 to 5 times the minimums would be a desirable minimum for practical purposes of storage and reproduction. The requirements per unit of body weight were about the same for young and old animals, although the young were more susceptible to pathological manifestations during privation. Their data also showed a tendency for the rate of depletion of vitamin A stores to decrease as depletion ad- vanced and reserves became smaller. Moore (1939), using nyctalopia and papillary edema as criteria substantiated the requirements established by Guilbert and co-workers. Lewis and Wilson (1945), using growth, blood levels, and liver storage as criteria also found that about 8 micrograms of vitamin A per kilogram of body weight was the minimum requirement for calves. Moore 22 51. (1993) presented data which indicated that the measurement of spinal fluid pressure is a fairly critical index of adequacy of carotene intake. 1 Using this as a criterion they determined that a carotene intake of 66 micrograms per kilogram of body weight should be a daily minimum require- ment for dairy calves. In work with pigs, Dunlap (193h, 1935) reported carotene require- ments having rather wide limits, namely 13 to 60 micrograms daily per kilogram of body weight. The low limit was sufficient for nearly normal gains but deficiency symptoms persisted, while the high level exceeded Ininimum requirements and provided for considerable storage. Braude st 21’ (1991) considered 100 I.U. of vitamin A per 10 pounds live weight daily t<> be the minimum requirement (approximately 6.6 micrograms per kilogram bOdy weight). With carotene, a level of 100 1.0. per 10 pounds live Weight daily was definitely subnormal (approximately 13.2 micrograms caretene per kilogram) while 300 LU. of carotene provided for normal growth. Hentges gt 5;. (1952) reported that 25 micrograms of purified Carotene (80-85 percent beta carotene) per kilogram of body weight was the minimum daily requirement for young pigs. Feeding 17.5 micrograms restored plasma vitamin A levels but did not provide for storage, while 10 micrograms overcame gross deficiency symptoms and promoted fair gains. Sheffy a 51. (195‘!) reported that 6 micrograms of vitamin A daily per kilogram of body weight will promote good growth and prevent the appear- ance of gross deficiency symptoms in baby pigs. A level of 12 micrograms restored blood plasma levels while 18 micrograms was considered to rep- resent the minimum necessary to provide liver storage of vitamin A. Frape 93 21. (1959) reported data on the requirements of baby pigs from one to 8 weeks of age. Using gain, plasma and liver vitamin A levels and cerebrospinal fluid pressure as criteria, they judged 600 1.0. to 800 1.11. per pound of feed to be the minimum requirement of the young pig for a stabilized vitamin A palmitate on a dry carrier. At this level liver storage was just detectable. Reifman e_t. 11;. (l9‘t3) in work with rats found the rate of absorption of vitamin A to be proportional to the concentration of the administered material. There was no relationship found between the rate of absorption of neutral fat and vitamin A. Barrick e_t_ 31. (1948) studied the absorp- tion of carotene and vitamin A from the gastro-intestinal tract of sheep. They found vitamin A to be absorbed more readily than carotene as ev- idenced by plasma vitamin A values. Because of its prominent role in vitamin A storage, in maintenance 01’ plasma vitamin A values, and its importance in metabolism in general, the liver was long thought to be the logiCal site of conversion of car- otene to vitamin A. This view persisted for several years in spite of the failure of many early workers to demonstrate conversion of carotene to vitamin A in isolated livers (Moore, 1957). In recent years, however, considerable data has accumulated to indicate the intestinal wall is the primary site of conversion. Ken and Thompson (1951), on the basis of evidence presented in an extensive literature review, concluded that carotene is transformed to vitamin A mainly in the intestinal wall and that it is carried thence by the lymphatics to the blood stream and finally to the liver. Alexander and Goodwin (1950) demonstrated conversion of carotene to vitamin A in rats in either the intestine or intestinal wall. Oral administration of carotene to rats with the intestinal lymphatic vessel cannulated resulted in a marked increase in the vitamin A content of the lymph. No carotene was observed in the lymph. Swick 35 21. (1952) reported that when large doses of carotene were given to pigs 6 to 7 hours before slaughter, there was a marked increase (up to 20 fold) in the concentration of vitamin A in the mesenteric lymph with a smaller rise in the blood plasma and in the intestinal wall. The authors concluded these results favored the conversion of carotene to vitamin A in the intestinal wall of the pig. Thompson £3 21' (1950) made extensive studies of intestinal conversion in pigs and rats. They found very little conversion until after the bile and pancreatic juice entered the intestine with the peak of conversion just proximal to the middle of the intestine. When the intestinal con- tents were washed from the living intestine vitamin A appeared almost exclusively in the wall of the intestine, indicating conversion in the ‘5111 rather than in the contents of the digestive tract. The efficiency C’f' conversion of carotene increased with the state of dispersion. Evi- dence also indicated that vitamin A is transported to the liver via the bliph . -10- Klosterman st 51. (1949) injected carotene suspended in water or in cottonseed oil into the blood stream of sheep. They found that the in- jected carotene was very rapidly removed from the blood stream. However, apparently this carotene was not converted to vitamin A‘as no increase of the vitamin in the blood or liver could be noted. Lambs given carotene orally, or allowed green grass for a short period showed an increase of vitamin A in the blood serum. These observations, coupled with the fact that no measurable amount of carotene is found in the blood of normal sheep, suggested that carotene is converted to vitamin A by sheep during digestion or absorption rather than by the liver. Church 22 51. (195k) studied the utilization of intravenously ad- ministered aqueous carotene by sheep and cattle. In wethers, increases in plasma vitamin A after carotene injections were highly significant. In calves, on the other hand, carotene injections caused no significant differences in plasma vitamin A values or liver storage. In addition, advanced vitamin A deficiency symptoms present in some of the calves were not relieved and appeared to progress during the 10 days of the ekperiment. Eaton st 31. (1951) reported a very limited conversion of carotene to vitamin A in the blood of vitamin A deficient dairy calves given intravenous injections of aqueous suspensions of carotene. Warner aund Maynard (1952) reported that intravenously injected carotene in coco- lrut oil gave no beneficial effects when administered to vitamin A de- ficient dairy calves. However, in a second trial with aqueous colloidal CEirwatene administered intravenously a significant increase in plasma Vitamin A was obtained. Hentges gt El“ (1952) studied the effects of carotene administered °11illy, intravenously and intramuscularly on vitamin A deficiency in pigs. -11- It was found that, with aqueous preparations of carotene, all three methods afforded complete recovery from vitamin A deficiency symptoms and normal plasma vitamin A levels. Orally administered carotene was converted most rapidly while intravenous injections were utilized before intramuscular injections. Carotene in cottonseed oil administered intra- muscularly remained at the site of injection and was ineffective in re- lieving avitaminosis A symptoms. Parrish gt El' (1951) studied the relative values of vitamin A and carotene in swine rations during ges- tation and lactation. Although there was no positive evidence that the carotene supplemented gilts or their pigs suffered from vitamin A de- ficiency, the data showed that unit for unit carotene is less effective than preformed vitamin A as a vitamin A supplement for swine during gestation and early lactation. During periods when the carotene or vitamin A intake is high animals have the ability to store carotene and/or vitamin A. In studies with rats, Davies and Moore (1935) showed that the adult rat is able to store, with massive doses, enough vitamin A in its liver to supply its theoretical requirements for a century. However, these superfluous stores are eliminated at a rapid rate until a state of stable storage is reached. Guilbert and Hart (193“) reported that the liver tissue of mature beef cows, reared under favorable conditions was found to have a concentration of vitamin A approximating that of high potency cod liver oil. Golding and Foot (quoted by Dunlap. 1935) reported storage of up to 1,000‘ 1.0. per gram of liver in pigs given high levels of vitamin A after they had vitamin A deficiency symptoms. There is some evidence that in storage, as in absorption and uti- lization, an aqueous medium may be superior to an oily medium. Sobel - 12 - £2,293. (19#8) in experiments with rats demonstrated that vitamin A was more effective (measured by liver storage) when dispersed in aqueous media than in oily solutions. Sobel and Rosenberg (1950) reported that, in rats,‘ orally ingested vitamin A in an aqueous dispersion was more effectively transferred to milk and stored in the offspring than vitamin A in oil solution (stores were # times as great). Frey and Jensen (19h6) reported that, in cattle, the rate of de- pletion of the hepatic reserves of vitamin A and carotene decreased as the hepatic reserves of the two constituents decreased. The data indi- 'cated that hepatic carotene reserves in cattle are maintained in direct proportion to the carotene intake. Braun (19h5) presented data which suggested that utilization of stored vitamin A first forces available carotene stores to be converted to vitamin A, thus decreasing the caro- tene level without decreasing the vitamin A level at first. There was . no correlation between carotenoid and vitamin A levels of the liver and those of the blood under normal conditions. Only upon rapid depletion and below normal storage levels was low vitamin A storage reflected by low'blood levels. Hentges 23 El' (1952) also found no direct relation- ship in pigs between plasma vitamin A and liver reserves while liver .reserves were in the normal range. Only when liver stores were almost «depleted did plasma vitamin A values drop uniformly. As plasma vitamin inalues dropped below 10 micrograms per 100 ml, liver stores were gen- erally 5 micrograms per gram or under, or nearly depleted. Riggs (1940) reported wide variations in the time required for depletion of vitamin A reserves in cattle, particularly in older animals. Guilbert and Hart (193‘!) in experiments with cattle reported that caro- tewie in the adipose tissue, which constitutes a part of the vitamin A 33F“, ‘flfiWI-F”" -13- reserve, may be withdrawn during vitamin A privation without coincidental withdrawal of depot fat. Brande 32 El! (1951) attempted to produce naturally suckled pigs with low vitamin A reserves. A four-year old sow which had been kept I under good conditions and had previously produced 5 normal litters was placed on a vitamin A deficient diet. After 20 months, just prior to farrowing her fourth litter while on the deficient diet, the first clin- ical signs of deficiency began to appear. The fourth litter was very weak and was raised artificially. The sow, although mated in several successive heats, did not conceive again. Three gilts from her first litter were also raised on the deficient diet and successfully bred. The first gilt farrowed a litter of 13, very weak and unable to walk but with no eye defects. The other 2 gilts received 5,000 I.U. of vitamin A daily the last 6 to 8 weeks of pregnancy and farrowed and raised normal litters. Davis and Hadsen (19hl) reported on an extensive study of vitamin A and carotene in cattle blood plasma. They found that long continued. inadequate carotene intake and vitamin A deficiency can be determined by blood analysis. The critical level of carotene in the plasma was found to be 20 to 25 micrograms per 100 ml of plasma, and for vitamin A in the .same sample about 16 micrograms per 100 ml of plasma. Cattle having caro- ‘tene and vitamin A values at these levels or above usually did not show Exvmptoms of vitamin A deficiency. Hentges 25 El' (1952) reported normal plasma vitamin A levels in pigs of 15 to 32 micrograms per 100 m1 of plasma. IPJJIsma vitamin A levels did not drop below 15 until liver stores were neuarly depleted. 3y the time plasma values dropped to 7 micrograms per 1CK3 ml the spinal fluid pressure began to rise, still without visible -1l+- @083 symptoms. Nightblindness occurred only when all measurable vitamin A reserves were exhausted. Braun (1954) and Sutton :3; al. (191+5) both reported that vitamin A and carotene decrease markedly in the blood plasma of cattle at the time of parturition and beginning lactation. The maximum decrease in blood plasma carotene was reached one week following parturition and amounted to 106 percent of the 3 week prepartum level. Parrish at a_]_.. (1951) found that in pigs the vitamin A concentrations in the blood serum of the dams decreased as parturition approached and increased during the days immedi- ately following parturition. In early work with rats Dann (1934) found that the amounts of vita- min A passed into the fetal liver during gestation were smll. harther, 7 the maternal diet only slightly affected placental transfer. Thus, new- born rat livers contained 5 to 10 I.U. of vitamin A irrespective of whether maternal stores were 600 or 12,000 LU. In dams given vitamin A concentrate maternal stores reached 180,000 I.U. but the fetal livers still contained only 20 1.0. These findings were essentially confirmed byBauman e_t- 11. (193% and Henry gt a}, (l9h9). Baker 2?. 9;. (1953) reported that neither the prepartum diet of beef cows nor their liver stores at parturition affected the vitamin A stores of their calves at birth. Braun and Carle (1916), on the other hand, found that while the liver contents of fetuses were all low and the dif- ferences too small to have an effect on the welfare of the normal calf, they did reflect the vitamin A status of the mother. The vitamin'A con- tent of the fetal liver was in direct relationship to the mother's diet. Spielman gt 3.1. (191+6) and Wise e_t 31;. (1946) also reported that in the normal bovine the prepartum diet may influence markedly the levels of -15.. bOEh Vitamin A and carotene in the plasma and liver of the newborn calf. They found that calves need not be deficient in vitamin A at birth, for feeding of massive doses of vitamin A (one million I.U. daily) during the latter stages of gestation resulted in considerable storage in the fetal liver. Foot g£_al; (1939) found stores of 6 to 9 micrograms of vitamin A per gram of liver in newborn pigs. When the dams were fed vitamin A de- ficient rations from 2 weeks before farrowing through lactation, the liver stores of the baby pigs at birth became exhausted by weaning (8 weeks). Adding one-half percent cod liver oil (potency: 1,000 I.U. vitamin A per gram) to the ration resulted in increased liver stores in the baby pigs by weaning. Whiting gt_gl. (1949) reported that supplementing the prepartum ration with 12,000 .I.U. of vitamin A daily per 100 pounds live weight in- creased the liver stores of vitamin A of newborn lambs, goats and pigs. Thomas £3 21. (1946, 1947) also found that the extent of placental and mammary transfer of vitamin A in goats and swine can be increased by the addition of large amounts of vitamin A to the diet of the pregnant female. Under normal feeding conditions newborn kids had negligible stores (average 0.2 I.U. per gram of liver), but newborn pigs had appreciable liver stores ,(average 16 I.U. per gram of liver). Daily supplemental doses of 100,000 11.0. during the late stages of pregnancy increased liver stores in new- born kids to an average of 33 I.U. per gram, while doses of 100,000 I.U. t1) sows increased the liver stores of newborn pigs to an average of 119 11.0. per gram. Benham (1943) reported that liver stores in the newborn Pig ranged from 5 to 1+7 I.U. per gram when the sows were on normal diets. Although the liver stores of vitamin A are low or negligible in the gewborn of the farm animals, colostrum is a rich source of vitamin A. n__ .. -16.. The colostrum of cows has been reported to contain an average of 600 to 800 I.U. of vitamin A per 100 ml, and 200 to 500 I.U. of carotene per 100 m1 (Dann, 1933; Luecke 9; 11., 1947; Chanda, 1953). Eden (19h8) reported sheep colostrum contains an average of 1,800 I.U. of vitamin A per 100 ml. Sow's colostrum, while not so high as other farm animals, is also a good source of vitamin A. Brande 3."; 11;. (1946, 1910?) reported the average vitamin A content of sow colostrum to be about 70 micrograms per 100 ml in sows on winter rations. Thomas _e_t_ 2.3:.“ (1916) reported the vita- min A concentration in sow colostrum averaged 170 micrograms per 100 ml. Bowland gt _a_l_._. (1949) reported similar figures. Colostrum from sows on pasture was found to contain 1&5 micrograms of vitamin A per 100 ml while colostrum from sows on dry lot contained 135 micrograms of vitamin A per 100 ml. . Moore and Berry (1944) showed that the plasma vitamin A of dairy calves at birth was low but showed about a 5 fold increase during the first 216 hours with the ingestion of colostrum. Maximum vitamin A and carotene values were attained at about 3 days of age after which there was a gradual decline. Calves deprived of colostrum and given whole milk instead showed very little increase in plasma content of vitamin A. Wise 23 E' (191+8) reported that the concentrations of carotene and vitamin A in the blood serum of calves from birth to 10 weeks of age were closely related to the types of feed consumed. Colostrum effected striking in- creases in the blood vitamin A of the newborn calf. Milk, even when pro- duced by cows on high quality roughage including pasture, did not prevent a continuous decline in blood serum vitamin A to levels in the deficiency range. Though good quality hay was available to the calves after 2 weeks 01’ age, they were 6 weeks of age before the intake of carotenoids from -17- this source was sufficient to increase the carotene and vitamin A content of the serum. Bowland gt 2;, (19h9) reported that sow's milk vitamin A, and par- ticularly colostrum vitamin A, was correlated with liver storage which, in turn was related to the ration. Parrish 23,31. (1951) reported that for pigs, vitamin A concentrations in colostrum from gilts receiving carotene were only one half to three fourths of those from gilts receiving preformed vitamin A. whiting gt g. (1919) and Thomas 5 3;. (191»7) both reported that the addition of large amounts of vitamin A to the rations of swine, goats and sheep will substantially increase the vitamin A con- centration of their colostrum. Numerous reports have shown a relationship between vitamin A utili- zation and other factors or nutrients in various species of animals stud- ied. Jackson (1931) in studies with rats showed that mineral oil causes a considerable loss of vitamin A if it is mixed with the source of vitamin A prior to ingestion. Separate administration only slightly affected vitamin A utilization. Dutcher 32,31. (193“) reported that the presence of mineral oil had no adverse effect upon the vitamin A potency of cod liver oil. However, relatively small amounts of mineral oil had a marked effect in lowering vitamin A potency from carotene. Carotene was voided in the feces in almost direct proportion to the amount of carotene fed, indicating that utilization of the carotene was almost completely pre- vented by mineral oil. lease and Steenbock (1939) reported that the rate of loss of vitamin A from the liver of the rat was not affected greatly, if at all, by the amount of fat in the diet, by feeding of rancid fats, or by the rapid depletion of fat from the liver as affected by the administration of - l8 - choline. Parham st 31. (1950) studied the influence of solvent extracted versus hydraulic processed cottonseed meal in beef cows. They found that although the difference in levels of blood fat was statistically sig- nificant, this difference appeared to have little relationship to levels of carotene and vitamin A in the blood. Raper (1950), in work with beef calves, showed that when the fat content of the ration was raised from 2 to 5 percent, the plasma carotene level rose significantly. Plasma vitamin A and liver vitamin A and carotene were not affected. Thomas gt_§l. (19h9) found that when young calves (under 90 days) had been on a high vitamin A intake, the reduction of vitamin A in the diet did not immediately change the plasma vitamin A concentration, whereas elimination of fat as well resulted in a marked increase. Calves which were changed from whole milk to skimmed milk had an increase in plasma vitamin A levels averaging h micrograms per 100 ml which persisted 5 to 18 days. Calves changed from whole milk to a homogenized skimmed milk-h percent lard mix- ture had no change in plasma vitamin A concentration. when skimmed milk was then substituted for the lard-skimmed milk mixture, an increase in plasma vitamin A occurred which ranged from 5 to 1“ micrograms per 100 m1. Ross and Gallup (1999) reported on studies with beef cattle which indicated an inverse relationship between the level of plasma inorganic phosphorus and plasma carotene. Cattle with low plasma phosphorus levels had been observed to have higher plasma carotene levels than cattle with normal or above normal levels of plasma phosphorus. Klosterman £t_gl. (1952) found that, in rats given equal amounts of carotene or vitamin A, liver stores of vitamin A were greater in the animals fed low phosphorus than in those fed high phosphorus rations. They also reported a highly significant negative correlation between plasma inorganic phosphorus and -19.. Vitamin A in lambs fed low and adequate phosphorus rations deficient in carotene. Gallup gt 5;. (1953) depleted steers of phosphorus and vitamin A reserves and then gave daily carotene supplements (half also received phosphorus). The plasma carotene levels were consistently higher in the steers on the low phosphorus ration while the plasma vitamin A values were lower. There was decreased liver vitamin A storage in the phosphorus deficient steers. The results obtained with lambs in a similar experiment showed a different trend to that noted in cattle. Plasma vitamin A values were higher, and the liver vitamin A stores were greater, in the phosphorus deficient lambs. Thomas gt El' (1953) reported similar results in beef cows with plasma carotene values generally higher in the phosphorus de— ficient cows than in those fed adequate phosphorus. Milk from the phos- phorus deficient cows contained more carotene but less vitamin A than that from cows fed adequate phosphorus. King st 21. (l9h0) in work with cattle found a reduced plasma vita- min C level occurs shortly after the symptoms of avitaminosis A appear. The subcutaneous injection of crystalline ascorbic acid seemed to allevi— ate several symptoms associated with lack of vitamin A, namely, a notice- able improvement in the rough scaly condition of the hair and skin and an attenuating effect upon retinal hemorrhages. Boyer st 31. (1942) also reported a definite indication of an interrelationship between blood jihasma ascorbic acid and vitamin A in dairy calves, particularly when vitamin A values fell below 10 micrograms per 100 ml. It was also found trust when vitamin A deficiency develops in rats the excretion of vitamin C: :is greatly reduced, indicating the lowered blood and tissue vitamin C iii! ‘the result of impaired synthesis. Mayer and Krehl (1948) found that one of the first symptoms of the vitamin A deficiency syndrome in the rat 4w ——n‘m-‘i‘xv was a depletion of the animal's vitamin C reserves, evidenced by symptoms resembling scurvy and curable by ascorbic acid, as well as by a decrease in the ascorbic acid content of the liver, blood and adrenals. Davies and Moore (l9#l) and Hickman g£_gl. (19#2) reported.a pro- nounced synergistic effect between vitamin A and vitamin E. It was no- ticed that vitamin E deficient rats had much lower vitamin A reserves than rats receiving equal amounts of vitamin A plus supplements of vitamin E. The data indicated that the effect of the vitamin E deficiency did not lie entirely in the inability of the liver to absorb vitamin A but also in a decreased power of retention after absorption. Prolonged deficiency of vitamin E led to a secondary deficiency of vitamin A as indicated by the disappearance of vitamin A from the liver. Also, a vitamin A deficiency was prevented by the addition of vitamin E to low vitamin A rations. ‘Hhiting‘gt'gl. (19h9) reported that supplementing the prepartum ration with tocopherols increased liver stores of vitamin A in the newborn lamb but had little effect on the liver storage of the newborn kid or pig. The vitamin A content of the colostrum was not affected in these species. Squibb 9.2 5;. (19%). Ellmore and Shaw (1949, 1951+) and Shaw 2?. §. (1947, 1951) have all reported that raw soybeans contain a factor which markedly depresses plasma levels of both vitamin A and carotene.in cattle. This has the effect of increasing the animal's vitamin A requirement. The effect is noticed when raw soybeans make up 30 percent or more of the ration. McGillivray (1951) published a report on the apparent intestinal synthesis of carotene by sheep. Carotenezlignin ratios were studied and measured at different points in the digestive tract, ingested food, and voided feces. The lignin recovery in the feces was 96 percent indicating negligible digestibility. The ratios remained relatively stable through the stomachs. In the intestine the carotenezlignin ratio decreased through the upper portion of the small intestine, increased through the ileum reaching a maximum in the cecum and decreased slightly through the colon and rectum. Some animals actually showed a negative carotene bal- ance. The author stated that synthesis of carotene by microorganisms had been demonstrated on an agar medium inoculated with cecal contents. PRELIMINARY STUDY A preliminary study was initiated approximately 2 months before the actual experiment began. The primary purpose of this study was to test the effectiveness of the basic ration in depleting gilts of their vitamin A reserves. The 5 Duroc gilts used were approximately 1+ months of age when they were placed on the basic ration early in May, 1958. During the next 2 months the gilts' plasma vitamin A levels declined only slightly. By the end of July the plasma vitamin A values were in the range consid- ered to be borderline (10 to 15 micrograms of vitamin A per 100 ml of plasma). During August there wasa rapid decline to approximately 8 micrograms of vitamin A per 100 ml of plasma, followed by a tendency for the rate of decline to decrease. By October 16, 1958 the plasma vitamin A values averaged 6 micrograms per 100 ml, indicating liver reserves of vitamin A were substantially depleted. No visible symptoms of vitamin A deficiency were present. It was decided to continue the preliminary study through a gestation period. Accordingly, after October 16, 1958, supplemental vitamin A was added to the basic ration at a level of 135 micrograms per pound of ration. The gilts were then bred and fed 6 pounds of feed per head daily during gestation. Since the gilts weighed about 180 to 200 kilograms, this level of feeding provided it to h.5 micrograms of vitamin A per kilogram of body weight daily. The plasma vitamin A increased to levels of 10 to 15 micrograms of Vitamin A per 100 ml by the end of November, then remained relatively -22- -23- stable during the rest of gestation. Four of the 5 gilts farrowed litters which were apparently normal and healthy. The baby pigs had no visible symptoms of vitamin A deficiency though there were only traces of vitamin A present in their livers. The fifth gilt did not farrow. PROCEDURE General Sixteen gilts were allotted to the trial when weaned on April 29, 1958. At this time their average weight was 21+ pounds with a range from 21 to 26 pounds. Twelve of the gilts were Durocs with 3 gilts coming from each of 1+ litters. The remaining ‘9 gilts came from a Chester-Durac- Hampshire crossbred litter. Table 1 shows the birth dates and litter size of the 5 litters represented. TABLE 1. LITTER DATA FOR THE GILTS Litter No.“ Date Pigs born Pigs born Pigs farrowed alive dead weaned D 11 3/1/58 9 0 9 D 12 3/2/58 11+ 2 9 D 17 3/5/58 9 1 8 D 20 3/7/58 11 o 10 x no 3/3/58 15 l 13 a. Duroc litters indicated by D, crossbred by X. The giltswere placed together in a pen on a concrete slab and self fed a standard growing ration until June 22, 1958. At this time their average weight was‘approximately 70 pounds with a range of 50 to 90 pounds. The gilts were provided a standard growing ration during this period for 2 reasons. It was desired to have the gilts receive a well balanced diet to get them well started during the early critical phase of nutrition fol- lOVing weaning. Secondly, it was decided to delay placing the gilts on a Vitamin A depletion ration so that they would be more likely to reach breading age by the time their liver stores of vitamin A were depleted. -2h- -25- The actual experiment began on June 22, 1958 and continued until the gilts weaned their second litters in December, 1959. A brief out- line of the experiment follows: I. June 22, 1958 to January 10, 1959: Depletion period. A. Two-thirds of the gilts depleted of vitamin A reserves. B. Gilts group fed in 2 groups, the depletion group and the positive control group. II. January 10, 1959: Gestation phase began. A. Depletion group further subdivided making 3 experimental groups in all. B. Individual feeding started. C. Breeding program started. III. May and June, 1959: First litters farrowed. IV. July and August, 1959: Gilts re-bred. V. October and November, 1959: Second litters farrowed. VI. December, 1959: Experiment terminated. Throughout the experiment a low vitamin A ration, designated the basic ration, was fed to all the gilts. Only the amount of synthetic vitamin A added to the basic ration varied among the experimental groups. Table 2 shows the ingredients and formulation of the basic ration. Table 2a shows the calculated composition of the ration and the recommendations of the National Research Council (National Research Council Publication 648, Nutrient-Requirements of Swine, Revised 1959) for the major nutrients lslkely to be deficient in practical swine rations. All the nutrients Ruaown to be needed by swine are provided in adequate amounts with the exception of vitamin A or carotene. Chemical analyses by the method of Iksoth (1957) showed only traces of carotene too small for accurate -26.. TABLE 2. BASIC RATION--INGREDIENTS AND FORMULATION (1,000. lbs.) ——-———————_—————————__—-'_—_—————————____——— Insredient Pounds 3h3.5 meat 0 O O O O O O O O O O O O O O O O O O O O O O O O ”.0 soybm .“1 O O O O O O O O O O O O O O O O O O O O O 80.0 “t8 0 O O O O O O O O O O O O O O O O O O O O C O O Heat&bonescraps..................’+0.0 Distiller's dried corn solubles . . . . . . . . . . . . 25.0 Supertracemineralsalta............... 5.0 Ground limestone. . . . . . . . . . . . . . . . . . . . 5.0 B-Vitamin concentrateb. . . . . . . . . . . . . . . . . 1.0 B3.2 Vim D suppl’uontd O O O C O C O O O O O O O I O O O 2.25 m. a. Trace mineral content (percent): Zn, 0.500; Co, 0.022; Mn, 0.h00; Cu, 0.0h8; re, 0.330; I, 0.011. . b. Pfizer supplement No. 1, containing 2 gms. riboflavin, h gms. pant- othenic acid, 9 gms. niacin, and 10 gms. choline chloride per pound. c. Pfizer supplement No. 9, containing 9 mg. per pound. d. Irradiated yeast with potency 0f lh2,000 I. . vitamin D per gm. concentmteceeeeeeeeeeeeeeeeeeee 005 TABLE 2a. BASIC RATION--COMPOSITION3AND N.R.C. RECOMMENDATIONSb Nutrient Content/lb. N.R.C. recommendations/lb. of ration of ration 100 lb. pig 300 1b. gilt '1'.D.N.,lb.' ' 0.75 0.75 0.70 Cr. protein,lb. 0.17 0.15 . 0.15 Calcium,lb. 0.007 0.005 0.006 Phosphorus,lb. 0.006 0.00h . 0.00# Riboflavin,mg. 2.8 1.0 1.5 Niacin,mg. 28.7 5.0 5.0 Pant. acid,mg. ‘ 10.0 h.5 - 6.0 Vitamin BlZ,mcg. 7.1 5.0 5.0 Vitamin 13.1.11. . 326 . 60 60 Carotene,mg. 0.05 0.75 2.50 a. Composition calculated from tables in Morrison (1956). b. Recommendations from National Research Council Publication 648, Nutrient Requirements of Swine, Revised 1959. -27- determinations, tending to confirm the low carotene content indicated in table 2a. Also, the ration was found to be effective in the depletion of vitamin A reserves during both the preliminary study and the actual ex- periment. Based on the estimated content in table 2a, 5 pounds of the ration would provide only 250 micrograms of carotene daily, or a maximum of 0.75 micrograms of vitamin A activity per kilogram of body weight during gest- ation for the lightest of the gilts. Even this maximum figure of 0.75 micrograms assumes conversion of carotene to vitamin A by the pig to be equal to that of the rat. Depletion Period On June 22, 1958, one gilt was selected at random from each litter group to serve as a positive control. These 5 gilts were placed in a sep- arate pen, making one pen of 5 gilts and one pen of 11 gilts. The 11 gilts were fed only the basic ration during the depletion period (June 22, 1958 to January 10, 1959). The 5 gilts designated as controls received the basic ration to which supplemental vitamin A had been added. The vitamin A supplement used throughout the experiment was a synthetic vitamin A pal- mitate stabilized in gelatin with a potency of 10,000 I.U. per gram. The synthetic vitamin A was added to the control ration at a level of 100 grams (1,000,000 I.U.) per 1,000 pounds of feed from June 22, 1958 to October 1, 1958. By October 1 the plasma vitamin A levels of the control gilts had (declined somewhat. Therefore, from October 1, 1958 until January 10, 1959 tlle added vitamin A was adjusted to 200 grams per 1,000 pounds of feed. Tile higher level of supplementation stopped the decline and restored Plasma vitamin A values to their original levels. Self feeders were used until November, 1958. By then the gilts were - 28 - becoming fatter than seemed desirable for breeding animals. Accordingly, all the gilts were changed from a self feeding to a hand feeding program on November 18th. They were then group fed (2 groups) at a rate of 5 pounds per head daily until January 10, 1959. The ration fed to each group remained the same as previously outlined. After the gilts had been receiving the experimental rations for about one month, a blood sampling program was initiated. Blood samples were taken at intervals of h to 5 weeks from July until October and ana- lyzed for vitamin A content. The plasma vitamin A levels of the gilts ~ on the deficient ration then began to decline. Thereafter blood samples were taken at intervals of 2 to 3 weeks. The blood samples were taken from the anterior vena cava by means of a hypodermic syringe. A 20 gauge, 2 inch needle worked well when the gilts were small. After they reached 100 to 125 pounds in weight, an 18 gauge, h inch needle was used with satisfactory results. One gilt- died on August 19, 1958, the second time blood samples were taken. Sub- sequent post-mortem examination indicated suffocation as the probable cause of death. Possibly needle damage to the phrenic nerve caused a respiratory spasm which resulted in death. However, the bleeding tech- nique proved very satisfactory after some experience was attained. None of the remaining animals exhibited any apparent ill effects from any of the several bleedings. Unfortunately, the gilt which died was one of the control gilts, which left only h gilts in the control group. The gilts were restrained with a snare on the snout while the blood sample was being drawn. This procedure was very satisfactory at first,‘ but when blood samples were taken every 2 weeks, some difficulty was en- countered. Restraint then became a problem as the sows would not lean - 29 - dway from the snare. Instead, they fought the needle considerably and Obtaining blood samples became very difficult. Therefore, after the end of December, 1958 the bleeding schedule was again lengthened to once every 9 to 5 weeks. With this length of time between sampling dates very little trouble was encountered in obtaining samples from the snared gilts. At each sample time, approximately 15 ml of blood was drawn. Heparin was used as an anticoagulant. The plasma was separated from the blood cells by centrifugation, and the plasma layer removed, frozen and stored at 0° F. until it could be analyzed for vitamin A content. By January 10, 1959, the control gilts had plasma vitamin A levels of 16 to 21 micrograms per 100 ml, whereas the levels of all the gilts on the depletion ration had been below 10 micrograms of vitamin A per 100 m1 of plasma for at least 3 weeks. This indicated substantial depletion of the vitamin A stores of the latter gilts since blood plasma vitamin A levels show only slight decline until liver stores are nearly depleted (Hentges st 51., 1952). Accordingly, the gestation phase of the study was begun. Gestation Phase For the gestation phase of the experiment 10 of the 11 gilts which luad been depleted of their vitamin A reserves were divided into 2 groups inith litter mates distributed as evenly as practical. The eleventh gilt, idlich was stunted and unthrifty, was discarded. To provide 5 control SiJis, a gilt from the preliminary study was transferred to the control acroup to replace the gilt which had died. For the remainder of-the ex- Ixsriment there were 5'groups of 5 gilts each, assigned to receive supple- hlental vitamin A as follows: (1) Group I, Control-16 micrograms of vitamin 1\ per kilogram body weight daily; (2) Group II, 5 micrograms of vitamin A per kilogram of body weight daily and (5) Group III, 2.5 micrograms of Vitamin A per kilogram of body weight daily. The level of supplemental vitamin A assigned to the control group was slightly lower than previously provided (approximately 20 micrograms per kilogram of body weight at the end of the depletion period), but was higher than that recommended by N.R.C. The gilts were moved into a barn on January 10, 1959 and the 3 groups were randomly allotted to 5 adjoining pens. Each pen contained 3 permanent and 2 folding stalls for individual feeding. The pens contain- ing groups I and II provided approximately 26 square feet of floor space per gilt, exclusive of the feeding stalls. The pen containing group III was slightly smaller, providing approximately 22 square feet of floor space per gilt. Each pen had a concrete floor and contained an automatic waterer. Hood shavings were used for bedding. Individual feeding was started on January 11, 1959. For the re- mainder of the experiment each gilt was placed in her respective feeding stall twice a day for feeding. As soon as the feed was finished, they were released. The control gilts received their daily supplement of vit- amin A continuously, the only difference being that instead of being mixed into the ration, it was now added to the feed each day. Each gilt of groups II and III, however, began to receive the supplemental vitamin A only after being bred. The individual daily doses of vitamin A were weighed on an analytical balance and mixed with a small amount of soybean meal. This was added to each gilt's morning feed. The gilts were weighed every 2 weeks and the daily supplemental vitamin A allowance was adjusted to body weight. The gilts were fed at a rate of 3 to 5 pounds of feed a day for the - 31 - rest of the experiment, depending upon individual rate of gain and con- dition. The only exception to this level of feeding was during lactation when the daily feed intake was increased to provide the additional nutri- ents required for milk production. During lactation the gilts received 8 to 12 pounds of feed daily, depending on litter size and individual condition of each gilt. The level of vitamin A supplementation remained unchanged during lactation. The breeding program was started on January 12, 1959. Each gilt was bred on 2 successive days during estrus to 2 different Yorkshire boars. If a gilt failed to conceive during the first estrous period, she was re—bred during the next. The gilts were boar checked daily until March 15, 1959. Each gilt had an identifying number formed by ear notches which were made at birth. The positions of the ear notches identified both the number of the litter in which the gilt was born and her individual pig number within the litter. When the gilts were moved inside the experi- mental barn, they were also assigned individual code numbers, from 1 to 15. Each gilt's code number was placed in the middle of her back i£§ numerals approximately one foot in height. During the winter, these numbers were formed in the hair with clippers. In the spring and summer, When the hair was short, the numbers were painted on. A card was then :placed on each feeding stall showing both the code number and the ear liumber of the gilt to be fed in that stall. In this manner, the possi- llility of mistakes involving identification was minimized. The code taumbers were also utilized to maintain the breeding records. Table 3 tshows the code numbers of, and the daily vitamin A levels fed to, each of the gilts . the one litt: My; (3 eac) - 32 - TABLE 3. TREATMENT GROUPS AND IDENTIFICATION NUMBERS OF THE GILTS J f Controla Group IIb Group IIIc Ear No. Code No. Ear No. Code No. Ear No. Code No. hO-lO l hO-lA 6 90-13 11 ll-# 2 #OblS 7 12-8 12 12-9 3 11-9 8 11-6 13 20-8 A 17-3 9 12-12 1h 1-10 5 20-7 10 20-9 15 a. Fed 16 micrograms of vitamin A per kilogram of body weight daily. b. Fed 5 micrograms of vitamin A per kilogram of body weight daily. c. Fed 2.5 micrograms of vitamin A per kilogram of body weight daily. The first litters, born in May and early June, 1959. were weaned at h weeks of age. As each litter was weaned, the gilt was returned to the experimental barn and re-bred. When a 'weaning' heat occurred within 7 days of weaning, it was passed and the gilt bred during her next estrous period. The gilts were boar-checked every day from the end of June until the middle of September, 1959. The same general breeding plan was fol- lowed, that is, each gilt was bred on 2 successive days by different boars. For the second litters each gilt was bred to a Hampshire boar the first day and a Yorkshire boar the second day of estrus. The second lit- ters were born in October and November, 1959. and were weaned at 5 weeks of age. The experiment was terminated for each gilt at the time of weaning. At the conclusion of the experiment, 9 of the gilts were slaughtered; the 5 gilts in group II and 2 gilts each from groups I and III. All but one of these gilts (one in group II) had failed to farrow their second litters. At slaughter, samples of the livers were taken for vitamin A analysis and the reproductive tracts were examined. The remaining 6 gilts (3 each in groups I and III) were allotted to a different experiment, -33.. and were re-bred. They were, however, kept on the same experimental ra- tion and the same levels of vitamin A supplementation. Collection of Data Each gilt was removed from the experimental barn, washed, and placed in a farrowing pen from A to 6 days prior to the expected farrowing date. She remained in the farrowing house until the litter was weaned, at which time she was returned to her respective pen in the experimental barn. At parturition the same general plan was followed throughout the experiment. The baby pigs were removed from the gilt as they were born, before they had opportunity to nurse, and were placed under a heat lamp. Each pig was given an identifying number by ear notches, arranged to iden- tify both the litter number and pig within the litter. At the time of ear matching the tips of the needle teeth were clipped and the navels dipped in tincture of iodine. Each pig was examined for signs of gross abnormalities, or deficiency symptoms. A_5 ml blood sample was then obtained from each baby pig. The blood was drawn from the anterior vena cava using a hypodermic syringe with a 22 gauge, one and one—half inch needle. After the blood samples were taken, every second male and every second female (in order of birth as nearly as possible) were sacrificed. Each pig to be sacrificed was killed with chloroform. The livers were immediately removed for subse- quent analysis to determine liver vitamin A storage at birth. The sacri- ficed pigs were then examined for signs of gross internal abnormalities. This examination included exposure of the optic nerves, and examination of the brain for possible hydrocephalus. The remaining pigs were returned to the gilt and a 10 ml sample of colostrum was taken. The colostrum was obtained by manual expulsion with - 3h - no difficulty. The blood plasma, liver and colostrum samples were then frozen and stored at 0° F. for subsequent analysis for vitamin A content. Additional blood samples from the baby pigs, and milk samples from the sows, were taken when the pigs were 24 hours, 72 hours and 168 hours of age. Fer these samplings, the pigs were taken from their mothers about 2 to 3 hours before the sampling time to allow the udder to fill. After the blood samples were drawn, the baby pigs were returned to the sow and allowed to start nursing, resulting in the initiation of milk flow. The milk was then expelled from the udder manually. Occasionally sufficient milk could not be obtained because of the limited time of the letdown. In these cases additional milk was obtained from the next let- down, usually oneéhalf to one hour later. From Site 10 ml of milk were taken at each sampling. These blood plasma and milk samples were also frozen and stored at 0° F- until the analyses could be accomplished. The samples were analyzed as rapidly as time permitted, usually within 2 to A weeks. None of the samples were stored for over 3 months prior to analysis. A storage trial indicated only slight loss in vitamin A content after samples had been frozen up to 6 months. The samples were all analyzed colorimetrically utilizing a Bechman DU Spectrophotometer. In all of the analyses, 1,3-dichloro-2-propanol (glycerol dichlorohydrin) was used as the color producing reagent. The plasma samples were analyzed by the method of Sobel and show (19A?). and the milk samples by the method of Sobel and Rosenberg (1999). The procedures used were essentially as outlined in the references except for adjustment of the volumes. Two ml samples of plasma, and 5 ml samples of milk were analyzed, and volumes of the reagents adjusted accordingly. The liver samples were analyzed by the method of Gallup and Hoefer (1946), modified in the last stage to -35- utilize 1,3-dichloro-2-propanol instead of antimony trichloride to pro- duce the color. RESULTS AND DISCUSSION Depletion Period and Sows' Vitamin A Status In the design of the experiment the 3 levels of supplemental vitamin A to be fed to the 3 experimental groups were chosen with the following objectives in mind. Group I served as the positive control group. This group of gilts was not depleted of vitamin A stores and was provided a level of vitamin A either meeting, or in excess of, N.R.C. (National Re- search.Council) recommendations throughout the entire experiment. During the depletion period these gilts were supplemented with 1,000 I.U. to 2,000 I.U. of vitamin A per pound of feed which is considerably in excess of the #00 I.U. per pound of feed recommended in the N.R.C. tables (Na- tional Research Council Publication 6fi8, Nutrient Requirements of Swine, Revised 1959). For the gestation phases of the experiment the gilts of the control group were allowed 16 micrograms of vitamin A per kilogram of body weight daily. The N.R.C. recommendations for gilts weighing 300 pounds is 7,200 I.U. of vitamin A per day; for sows weighing 500 pounds. the recommendation is 9,000 I.U. of vitamin A per day. Since one I.U. of vitamin A is the equivalent of 0.3 micrograms of vitamin A, 7,200 and 9,000 I.U. are the equivalents of 2,160 and 2,700 micrograms respectively. These values correspond to recommendations of 15.8 micrograms of vitamin A per kilogram body weight daily for 300 pound gilts and 11.9 micrograms per kilogram body weight for 500 pound sows. The gilts averaged 350 pounds in weight at the beginning of the first gestation period and about “75 pounds at the end of the experiment. Therefore, the level of 16 - 36 - - 37 - micrograms of vitamin A per kilogram of body weight daily is equal to, or higher than, N.R.C. gestation recommendations. The level was not adjusted during the lactation periods to meet N.R.C. lactation recom- mendations of 2%.6 and 22.0 micrograms of vitamin A daily per kilogram body weight for 350 pound gilts and #50 pound sows, respectively. In view of the fact that the level fed should provide considerable storage, it was decided to maintain the constant vitamin A intake during lacta- L -I I tion. The gilts in groups II and III were depleted of their vitamin A stores prior to breeding so that the experimental results would be aff fected as little aspossible by previous storage. It was desired to supplement group II with a level of vitamin A which would represent approximately the absolute minimum requirement. Therefore, a level of 5 micrograms of vitamin A per kilogram of body weight daily was provided. As was pointed out in the review of literature, several workers over a period of years have reported this or a slightly higher level to be re- . quired by growing animals to prevent deficiency symptoms with no excess for liver storage. It was desired to have the gilts in group III sup- plemented at a lower level which would prevent an acute deficiency, but would probably be suboptimum for gestation. Accordingly, they were sup- plemented at the rate of 2.5 micrograms of vitamin A per kilogram of body weight daily. Table # shows the weights of the gilts at the start of the experi- ment, and at the beginning and end of each gestation period. The gains exhibited during the growing and gestation periods compare favorably with What is normally expected in practical swine management programs. The gains were not excessive, yet difficulty was encountered in keeping the TABLE 4. REPRESENTATIVE LIVE WEIGHTS OF THE GILTS (lbs.) - 38 - Date 6/17/58 1/9/59 5/7/59 7/3/59 10/9/59 Gilt no. Control group 1 56 319 #56 384 #78 2 78 352 42h A59 478 3 67 315 #47 362 #26 ‘0 72 349 ‘65 39+ ”'67 5’ _: ; E 17.2 E Avg. 68 334 ##6 415 #79 Group II 6 76 345 456 #95 #57 7 80 309’ #13 393 #70 8 55 316 M9 the M1 9 79 363 475 #35 #7“ 10 a ' 2 E 23.5 227. Avg. 72 3h1 #56 A28 #60 Group III 11 52 351 ‘+81 399 470 12 85 373 #72 #09 #98 13 80 339 A31 A78 #85 1h 52 29h has 38% #26 15 a 2+2 25.9 2'2 22 Avg. 69 3A1 Ash 423 A83 a. Added to the control group on February 10, 1959 to replace a gilt which had previously died. gilts in good breeding condition. finement and lack of exercise the gilts showed a marked tendency to be- come overly fat . restricted to 3 to 5 pounds daily per animal during the gestation periods, depending upon individual condition. most of the gilts were fatter than was desirable for breeding animals. Because of the relatively strict con- To combat this fattening tendency, feed intake was In spite of this it was felt that An exception to this general trend occurred during the period of -39- lactation in May and June of 1958. Generally those gilts which farrowed and nursed litters finished lactation in a trim and thrifty condition. Once the litters were weaned however, the gilts began putting on fat and by the middle of the second gestation period it was felt they were again fatter than was desirable. Table 5 presents representative plasma vitamin A levels for the gilts. While the collection dates shown include less than half of the total number of samples analyzed during the course of the experiment, they serve to illustrate the general trends found. On July 22, 1958, about a month after depletion had started, all the values were well within the normal range. From then until November 13, 1958 there was only a slight reduction of plasma vitamin A in the 2 depletion groups. This gradual decline varied considerably from gilt to gilt and was not always uniform for any one gilt. After November 13, 1958 the plasma vitamin A values for groups II and III showed much more rapid and con- sistent decline until December 18, 1958. Samples collected on December 18, 1958 and January 9, 1959 showed almost identical vitamin A levels, for each of the gilts on the depletion ration, of 10 micrograms or less <>f vitamin A per 100 ml of plasma. These low plasma values, according 'to the work of Hentges 23.51. (1952), indicated the liver stores were nearly depleted. ‘ The plasma vitamin A values of the control gilts stayed within the riozmnl range throughout the experiment, although they were slightly lower <3lnring the first winter than the rest of the time. After the first lit- ters were weaned, however, the plasma vitamin A levels stayed fairly high, generally being 25 micrograms per 100 ml or higher. In table 5 tale values of 22.8 and 17.8 for gilts h and 5¥respectively, on .ooau hamsow>oam um: sown: pawm d oomamou on mmmfi .OH hhmsnpoh so macaw Houusoo o» cocu< .n .mwmhdmnm wmfiusv umoa moflmsmm .m m.mm 95 m6.” w.~a wé. 95.. “um. . .92 elem slam .mldm m M“ Noam ma ma N.mm H.mm :.m~ m.mm o.m m.wH N.om :H N.mH n.5H m.ma m.¢ :.m :.NH o.Hm ma Emm v.9 NAH mé 0.x lama mdm m." ism TS . mama v m 02 odd mew d HHH maomw m.mm 3.5H m.oa H.:H w.u w.NH :.wH .w>< mm a ...“.IAIH wdml mum: Nd. mm 2 . m.mm 5.5H m.wH m.mH m.m m.:a m.om 0 MW H.0H ¢.md N.mH N.oa m.u o.ma m.om m . :.wm o.ma n.wa 0.5H m.w m.:H n.ma m n.0m w.om :.mH . m.ma m.¢ . :.NH m.~m m % m.mm flow mu: flow TS 9mm m.n~ .95 mam mam .fllfl. 4| |.| Jul ...I an w.- m.mH :.mH H.0N m.om m.NN w.mH : 9% sea 03 ima 03 mfim . Tum m w.an w.:H N.:H n.wH m.wH o.mH m.Hm N m.u~ n.mm H.0N n.mm m.mH m N.HN H Houumoo .0: 30m anxmmsa Ram} «.9an Ram} Rah Raga mmxmmxa “.3838 8a .m 32 8Q 65 made ”as no mafia < 22%; sag EEEEEEE .m mamas / A. ' i l 1 . A v’ . '.q ' i '1‘. II- .I __ f 1" i * - /" | r...- ‘H: ‘ P I I ." ': Z I ‘v ' ""- - '_-...--.. |. ' , .- m g - 41 - October 22, 1959, seem inconsistent. This is probably merely an exhi- bition of the variation always present in biological subjects, for both of these gilts had much higher levels of plasma vitamin A both before and after this particular sampling date. Considerable individual vari- ation was present in each of the groups as well as a certain amount of fluctuation of plasma vitamin A levels for each gilt. The plasma vitamin A values for the gilts of groups II and III showed a marked rise when the feeding of the daily allowance of supple- Hi mental vitamin A started. Each of the gilts of these 2 groups began to 5” receive their allowance of vitamin A the day they first came into heat A I after breeding started on January 10, 1959. This procedure was adopted it so that the vitamin A history at the time of breeding would be uniform. By January 30, only gilts 10, l2, l3 and 15 had not been bred. In table 5 it may be seen that these gilts still had low levels of plasma vitamin A. while all the bred gilts had shown a substantial rise. The only ex— ception was gilt 6 and she had received supplemental vitamin A for only 2 days before the blood sampling date. By February 27, all of the gilts had been bred and their plasma vitamin A levels had all shown a substan- tial rise. By the end of April, just before farrowing started, there were no real differences in the plasma vitamin A levels between any of the 3 groups. This general pattern was maintained for the rest of the exPeriment. During the preliminary study (see p.22), vitamin A supplementation of approximately it to 10.5 micrograms per kilogram of body weight daily per animal during gestation, after previous depletion of liver vitamin A stores, caused only slight increases in plasma vitamin A content. Thus, thifii rapid and substantial rise in the group III gilts had not been -142- anticipated. While the level of 5 micrograms of supplemental vitamin A per kilogram body weight daily fed to gilts in group II could reasonably be expected to restore plasma vitamin A levels, it was felt a level of 2.5 micrograms of supplemental vitamin A would be insufficient, at least for rapid restoration of the plasma vitamin A levels of group III. Why this was not the case is unexplained. The basic depletion ration was the same as that used in the preliminary study. At the end of the experiment the gilts which did not farrow litters in the fall of 1959 were slaughtered. One gilt of group II which had farrowed her second litter was also slaughtered as she was the only gilt remaining in her group. At the time of slaughter liver samples were taken and analyzed for vitamin A content. Two additional gilts were later removed from the succeeding experiment and their liver storage was also checked since there had been no ration change. The liver vitamin A content of each of the gilts slaughtered is presented in table 6. TABLE 6. LIVER VITAMIN A CONTENT FOR THE GILTS (meg./gm.) Gilt Group‘ Slaughtered Liver vitamin A 2 Control 1/12/60 173 3 Control 1/12/60 1h? 5 Control 6/1h/60 121 6 II 1/12/60 54.6 7 II 1/12/60 22.6 8 II 12/8/59 33.1 9 II 1/12/60 37.2 10 II 1/12/60 21.3 11 III 5/4/60 8.0 13 III 12/8/59 10.6 In III 1/12/60 7.? a. Dietary vitamin A intake: Control-l6 micrograms; Group II-5 micrograms; and Group III-2.5 micrograms, of vit- amin A per kilogram body weight daily. -43- It is immediately apparent that the levels of dietary vitamin A had a marked effect upon the level of liver storage found in the gilts. The differences in the levels of vitamin A storage of the 3 groups are highly significant (P<.Ol). Moore and Payne (1942) reported the storage of vitamin A in livers obtained from an English butcher who knew the history of the animals. The average vitamin A reserves of adult sows was 100 I.U. of vitamin A per gram of liver, and of 6 to 8 month old pigs was 22 I.U. per gram of liver. Harms (quoted by Moore, 1957. p.460) conducted a similar study in Germany where the average levels were 85 I.U. and 18 I.U. of vitamin A per gram of liver for adult pigs and young pigs respectively. Converting Inter- national Units to micrograms gives average liver stores of 25.5 to 30 micrograms per gram of liver for adult pigs and 5.1+ to 6.6 micrograms per gram of liver for young pigs for the above mentioned reports. The liver vitamin A levels of 121 to 173 microgams of vitamin A per gram of liver from gilts of the control group are considerably higher than the average levels listed in the preceding paragraph. Apparently the supplemental level of dietary vitamin A was sufficient not only to meet the needs of the gilts, but also to provide for the accumulation of con- siderable storage. The liver reserves of the gilts of group II were con- siderably lower than the reserves of the control group. Even so, their reserves were similar to the average figures in the preceding paragraph and indicated that the level of supplemental vitamin A had been sufficient to provide some excess for storage. The 3 gilts from group III all had low levels of liver storage. At the end of the depletion period, the blood plasma vitamin A levels indi- cated that liver stores in the depleted gilts were nearly gone. Although -hh- there was no way of knowing exactly what the depleted liver vitamin A levels were, a comparison of the plasma vitamin A values at that time with those reported by Hentges and co-workers (1952) would indicate the liver stores were in the neighborhood of 5 micrograms of vitamin A per gram of liver at the end of the depletion period. Approximately a year later there was still no evidence of any substantial storage in the gilts on the low vitamin A intake. The supplemental level of 2.5 micrograms of vitamin A per kilogram body weight daily was apparently insufficient to provide liver storage of vitamin A even though plasma vitamin A values were restored. It is recognized that only a small number of livers were analyzed. Nevertheless, the marked differences found in the liver vitamin A reserves of gilts from different groups, the consistency of these differences, and the complete history of the background of the gilts, seem to warrant some ‘ postulations. From the standpoint of the health and well being of the gilts themselves, it appears that the low level of vitamin A intake pro- vided the gilts of group III, was either adequate or borderline, since plasma vitamin A levels were restored and maintained, yet there was little or no storage after a prolonged period of time. The vitamin A intake of the gilts of group II, based on this criteria, was definitely adequate since some liver vitamin A stores were accumulated, whereas the control gilts apparently received a substantial safety margin in their dietary Vitamin A. These observations agree well with observations of the gilts during the experiment. The gilts remained healthy and vigorous at all times, with no visible symptoms of a lack of vitamin A. Fertility The gilts were hand mated for both litters. Each gilt was bred on -15- 2 Successive days to 2 different boars each time she was in heat. The results of the 2 breeding phases are shown in table 7. During the first gestation period the reproductive performance of the gilts, while not exceptional, was satisfactory. Four of the 15 gilts returned to heat after being bred the first time. Of these, breeding was successful for gilt number 7 the second time she came into heat, and for gilt number 14 the third time. Gilts 2 and 13 failed to produce litters after being bred in 3 successive heat periods. Gilt 5 did not farrow although her breeding record indicated she had conceived. This was the gilt which was added to the control group to replace one gilt which died early in the experiment. She did not enter the experiment until midway through the breeding program and was first bred on February 20 and 21. Since the breeding program was terminated 22 days later, it is possible she actually returned to heat but was undetected. During the second gestation period the breeding performance of the gilts was definitely aubnormal. Only 7 litters were born, 3 in the control group, one in group II and 3 in group III. 0f the gilts which failed to produce litters, gilt 2 (group I) and gilt 13 (group III) also failed to have litters the previous breeding, and were repeat breeders during both periods of breeding. The remaining 6 gilts which failed to farrow the second time had all produced apparently normal and healthy first litters. Gilts 8 and 10 (group II) failed to resume estrous cycle activity after weaning their first litters. The remaining # gilts came into heat nor- fllilly'and were bred after weaning their first litters. Gilts 3 (group I), 6 (group II), and 14 (group III) had apparently normal estrous periods but; gilt 9 (group II) would not stand for the boar the second day. None Of ‘these gilts showed any evidence of estrous cycle activity after being I 45‘ I A 1 _‘ / / . M _._...——— -_w - 46 - TABLE 7. BREEDING PERFORMANCE First litters Second litters Gilt Times in Farrowed Times in Farrowed heat a heat Control 1 1 yes 1 yes 2 3 no 3 no 3 1 yes 1 no A 1 yes 1 195 5 1 no 1 yes F Group II 1“ 6 1' Ayes 1 no i . 7 2 yes 1 yes I 8 1 yes 0. no 9 1 yes lb no 10 1 yes 0 no Group III ’ ll 1 yes 1 yes 12 1 yes 1 yes 13 3 no 2 no 14 3 yes 1 no 15 1 yes 1 yes a. Each gilt was bred twice during each heat unless otherwise indicated. b. Bred only once, would not stand for boar the second day. bred the first time, and were considered as having conceived and due to. farrow. The possibility that the gilts may have been overlooked on a v/ return heat is'rather remote. The gilts were boar checked daily from late June until the middle of September. While it is possible an oc- casional gilt in heat might be missed, it is highly unlikely that this confild account for the high percentage of breeding failures. It was interesting to note the fertilization pattern as evidenced -L,7- by the color markings of the litters born. During the second breeding Period, boars of 2 different breeds were used, a Hampshire boar for the first service and a Yorkshire boar for the second service the next day, so that the sire of each newborn pig could be identified. All of the pigs born in 2 of the litters showed Hampshire markings (black with white belt), # of the litters were sired entirely by the Yorkshire bear (all white pigs), and only one litter contained pigs from both sires. The appear- ance of all black litters could be expected, for if a gilt ovulated early all the eggs could easily be fertilized before the arrival of Yorkshire sperm. If a gilt ovulated late in the estrous period, on the other hand, it would be expected that some eggs would be fertilized by each sire, since viable sperm from each should be available. Nevertheless, only one litter contained pigs sired by both boars, although in h other litters all the pigs were white indicating fertilization should have occured when sperm from both boars were present. At the termination of the experiment the 3 control gilts and the 3 gilts of group III which had produced litters during the fall of 1959 were transferred to another experiment, but left on the same rations. The re- maining gilts were slaughtered and their reproductive tracts examined-by Dr. J. E. Nellor, a reproductive endocrinologist at Michigan State Uni- versity. Three gilts of group II, numbers 6, 7 and 9, possessed repro— ductive tracts which were apparently normal. Of these, gilt 7 had had normal reproduction but had been slaughtered because she was the last remaining gilt of her group. Gilts 6 and 9 failed to produce second litters although their reproductive tracts were apparently normal and breeding records indicated they should have conceived. The reproductive tracts of the rest of the gilts showed evidence of various ovarian - 48 - abnormalities. The ovaries of gilts 3 (group I), 8 and 10 (group II), and 14 (group III) showed evidence of cyst formation. At the time of examination no large cysts were found, but the examination indicated that previous cysts had apparently regressed. In gilts 3, 8 and 1% the old cysts from follicles which had not ovulated had apparently subsequently regressed and luteinized. It appeared these gilts may have had non- ovulating post-parturient follicular development resulting in cystic ovaries. Gilt 10 also showed evidence of cystic ovaries, but the old cysts had not luteinized and the uterus exhibited very strong estrogenic effects. There were some corpora albicantia from previous ovulations, indicating at least sporadic ovulation for this gilt. The other 2 gilts, numbers 2 (group I) and 13 (group III), did not show definite evidence of ovarian cysts. Neither of them showed any evidence of recent ovulations, however, and it was felt they were either non-ovulatory or ovulated only very sporadically.» Since these observations were made some h to 5 months after the breeding program, it is not known what changes may have taken place in the reproductive tracts in the interim. Nevertheless, it appears that the reproductive failure of most of these gilts could be traced to ovarian malfunction. Hhile, with the limited numbers of animals in the experiment, vit- amin A cannot be eliminated as a cause of the reproductive failures, the evidence does not indicate it was a major cause. The reproductive per- formance of the gilts of group III on the low level of vitamin A supple- mentation was equal to, or better than that of the control group. The most serious failure occurred in the gilts of group II. This is certainly not the pattern that would be expected if vitamin A was the major cause Of the reproductive problems of the experiment. Only one of the gilts -49- Showed evidence of reproductive failure indicative of vitamin A deficiency. Gilt number 11 (group III) passed 9 stillborn fetuses in advanced stages of resorption, and 3 living normal pigs in her second litter. She also aborted her third litter of pigs about 12 days before she was due to farrow. Although on another experiment neither her ration nor the level of supplemental vitamin A had been changed. There are several possible factors which might have been involved in the relatively high incidence of reproductive failure. As noted previously, many of the gilts were fatter than was considered desirable for optimum breeding performance. This might very well have been a contributing factor in the difficulty encountered. It seems unlikely, however, that over- condition alone was a major cause of reproductive failure. From obser- vation of the gilts it was noted that several of the best breeders were among the fattest of the gilts in the experiment. On the other hand, gilt 3 was probably in the best breeding condition, yet failed to produce her second litter. The lack of exercise is another condition which may have contributed to the breeding difficulty. Good livestock managers recommend considerable exercise for all classes of farm livestock, including swine. The facili- ties used in this experiment, plus the need to keep the gilts away from any vegetation which would supply carotene, made it impractical to provide I special exercise area for the animals. Thus, they were kept in a rel- atively confined area which permitted very little exercise. The 22 to 26 square feet of floor space provided each gilt provided only slightly more than adequate housing area. The only real exercise the gilts received throughout the experiment was the bi-weekly walk to the scale pen, which was a distance of approximately 60 to 75 yards from the experimental barn. -50.. In Spite of having less opportunity to exercise than is desirable for breeding animals, the confinement did not affect the general health of the gilts. None of the gilts showed any signs of stiffness or lethargy which might be associated with lack of exercise. 0n the contrary, they seemed healthy, vigorous and alert at all times. Also, while it is generally agreed that exercise is beneficial, little is known of the amount of ex- ercise needed, or the specific effects of lack of exercise alone. There- fore, it is difficult to assess how much effect this lack might have had upon the reproductive performance of the gilts in this experiment. Another possibility is that some dietary factor, or factors, needed for normal reproduction may either have been missing from, or present in insufficient amounts in, the ration. The ration was supplemented with the known minerals and vitamins, except vitamin A, likely to be deficient in practical swine rations. Nevertheless, there is experimental evidence to indicate that nutritional factors which have not yet been identified may be required for normal reproduction in swine. Krider st 51. (l9h4) reported that either distiller's solubles or alfalfa meal markedly im- proved a growing ration containing corn, tankage, fish meal, cod liver oil and minerals. In the same year Ross 23 51. (194A) and Cunha 32 51. (l9hh) both reported that the addition of good quality alfalfa allowed nor— mal reproduction with an otherwise inadequate dry-lot ration of corn, soy- bean meal, and minerals, with or without one or 2 percent of brewer's yeast. Cunha 23 El' (19h8) reported similar results with cull peas used as a protein supplement. In a series of papers, Fairbanks £3 51. (l9h5), and Krider gt El' (1946) reported that fish solubles, rye pasture, or alfalfa meal all proved to be adequate supplements to similar diets. Apparently high quality pasture contains some factor or factors needed - 51 - for satisfactory results during reproduction. The papers mentioned above indicate that adequate amounts of high quality alfalfa meal, fish solubles or distiller's solubles work well as a pasture substitute with dry-lot rations. The fact that several of the papers indicated the unknown fac- tor or factors could be stored for later use suggests that the B-Complex vitamins were not the only nutrients involved, although it is possible they may have contributed to the effects noted. A similar conclusion applies to vitamin 812 since, as far as is known, alfalfa meal does not contain vitamin 312, yet was an effective supplement to the dry-lot rations used. It was obviously impossible to include the recommended 10 percent of alfalfa meal in a vitamin A deficient ration to insure against possible lack of unidentified factors. Some fish solubles also contain fair a- mounts of vitamin A activity. A small amount of distiller's dried corn solubles (2.5 percent) was added to the ration. This amount added only insignificant amounts of carotene to the ration and it was hoped that it would help to provide any unknown factors that might be lacking in the basic ration. It was also hoped that increased knowledge of nutritional requirements and ration formulation would help to provide an adequate bal- ance for reproduction. There is still the possibility that unknown fac- tors may haveleemnpresent in insufficient amounts or improper balance in spite of these precautions. The observation that the reproductive pro- blems were not encountered to any great degree until the second gestation period is consistent with what might be expected if unknown dietary fac— tors were involved. Factors which still remain unidentified are probably needed only in very small amounts, or require considerable time for de- pletion. - 52 - If there was a dietary factor involved in the reproductive problem encountered, considerable individual variation in its requirement was e- vident. Four of the 6 gilts remaining after the termination of the ex- periment have since farrowed normal litters. One of the control gilts failed to farrow a third litter and was found to have cystic ovaries. She was the replacement gilt which had failed to farrow in the spring of 1958, but had a litter of 7 pigs in the fall of 1958. The other gilt which did not produce a third litter aborted about 12 days before she was due to farrow. Four of the aborted fetuses appeared to have died just prior to abortion while the other 9 were in various stages of resorption. The possibility of a disease problem was also considered. However, veterinary examination and laboratory blood tests by the Pathology Depart- ment failed to indicate the presence of any infectious disease in the . gilts. There is no way to arrive at a positive answer from the data a- vailable in this experiment. It seems likely that several of the afore- mentioned factors contributed to the abnormal reproduction encountered. Litter Performance The first breeding and gestation period resulted in the birth of 12 litters: 3 to control gilts, 5 to gilts of group II and h to gilts of group III. During the second breeding and gestation period 7 litters of pigs were born: 3 to control gilts, one to a gilt of group II and 3 to gilts of group III. A summary of the number of live pigs born, and weights at birth and one week of age is presented in table 8. The over- all performance, based on these criteria, of the litters born to gilts of all 3 groups is entirely adequate. There was no indication of any real differences in litter size, birth weights, gain or livability which could be attributed to the different levels of vitamin A fed during gestation. .uoHHHno aHucoamaam .uans «spam on» news mmwa HH< .m .somuos umpmom an cenwmu swam .souuwH newsman uHHu .u .eoae ”He .mmaa eonssun moans .o .3osumu no: uHa .v .hmu saw so voHU .sHmw no: own wHA anus 0:0 .0 .auu goes so cone .zonw o» eoHauu .sHam an vegans” was 0:0 .p .moOHuoa soH»Mamow anon mcfinsv reason 00 uoHHmu nH was N moHHw .e o.w w.N o.m w.m mum mMOH ..w>< :.w m.m NH Hm . o m.m 5 am mH e o.m H.n NH ms :H m m.m ma aw m.m m.~ ca mm ma ~.m n.n n mm o.m o.m HH mm HH HHH macaw . as K his .2. z, u :.u m.n HH no 0H :1 u ~.o ~.n o co m . u m.w H.n HH mm m 5.: a.m HH mm « H.w o.m HH mm m u o ¢.m : mm o HH gnome H.n m.~ Ha :.m s.m u.a .m>< as ...n a a I l I a n m.: m.~ MH mm ~.m H.m a ow a u m.m m.m NH Hm n on.: m.~ nH mm mo.m m.m nH mm H Houusoo .x: H 6 .u: 5: 5.39 osHHe genes: J? H s .9: .9: 5.33 o>HHm season ommuo>< ommuo>< chop mmwm noquA ommao>< owmno>< shon owwm houqu euHHo mnouuuH scooom nuoapwH umnah mw< ho Mum: mzo Qz< mfimHm B< mBmUHmz .zmom mHQZDz "Moz<=mofimmm mmaaHA .w Hangs -51.- Although a few of the litters had fewer than average live pigs born, They were fairly well dispersed through the 3 groups and did not appear to be the result of the vitamin A treatments. During the farrowing of the first litters several of the gilts were hostile toward their pigs with the result that 2 litters were lost and a third litter had to be transfered to a foster mother. This hostility ranged from mere nervousness of the gilts with occasional snapping at the baby pigs to extreme viciousness where any pig which could be reached was immediately killed. While the incidence of hostility seemed higher than expected in normal swine operations, it seemed to be about evenly dis— persed between the experimental groups and there was no evidence to in- dicate it was caused by the levels of vitamin A fed. Gilts 3 and 5 (group I), 8 and 9 (group II), and 12 (group III) were quiet and comfortable during farrowing and accepted their pigs with- out hesitation. Gilts one and # (group I), and 11 and 1“ (group III) were quite nervous during and after farrowing and would occasionally snap at the baby pigs which ventured too near their heads. They did accept their pigs however, and no further difficulty was encountered with them. Gilts 6 and 7 (group II), and 15 (group III) were extremely vicious and immediately killed any pig that could be reached. Gilt 6 remained hos- tile for about 8 to 10 hours after farrowing and had killed one of her pigs before she would let the remaining pigs nurse. They failed to sur- vive however, and were found dead the following morning. One had been overlaid and the other 2 had apparently chilled and showed evidence of scours. Gilt 15 was even more vicious and would attack a man as well as her pigs. EVen after being placed in a farrowing crate she refused to let the pigs nurse and killed any which approached her head. Her entire - 55 - litter was finally killed. Gilt 7 also killed any pigs she could reach and refused to let them nurse for 8 hours after farrowing. Her remaining pigs were finally raised by gilt 4 which had farrowed at approximately the same time. It was decided to inject a tranquilizer into other gilts which dis- played evidences of hostility toward their pigs. Only one other gilt, number 10 (group II), seemed inclined to refuse her pigs during the first farrowing period. An intramuscular injection of 5 ml of Sparine (pro- mazine hydrochloride) was given after which the gilt accepted her pigs without trouble. When the fall litters were born, gilts 7 and 15 be- haved essentially the same as with their first litters. Accordingly, 5 m1 of Sparine were injected into the ham of each gilt. This proved remarkably successful, and within 20 minutes of the injections the gilts had become sufficiently quiet to allow their pigs to nurse. After once accepting their pigs both of these gilts were very good mothers. A few pigs were stillborn, but the incidence did not seem higher than normal. In the control group, there was one stillbirth in each of litters 61, 62, 66 and 82. Litters 65 and 68 of group II contained one stillbirth each. Litters 59, 81 and 8? of group III also contained one stillbirth each. The number of stillborn was not excessive and did not appear related to the ration treatments. With litter 85, the second litter of gilt 11 (group III), a dif- ferent situation was encountered. In this litter, along with the 5 living, normal pigs born, 9 fetuses in advanced stages of resorption were passed at farrowing time. These partially resorbed fetuses were 2 to 5 inches long and were barely recognizable as pigs. This apparently was not merely a chance occurrence, for this gilt was maintained -55- on the same ration and re-bred after termination of the experiment. Her third litter, born on another experiment, was aborted about 12 days be- fore she was due to farrow. Four of the 15 aborted pigs had recently died and appeared normal. The remaining 9 fetuses were in various stages of resorption and decomposition, ranging from barely recognizable fetuses about 5 inches long to fetuses of about one pound in weight in which decomposition had barely started. Unfortunately, the gilt died as a result of hemorrhage and shock following a liver biopsy performed to obtain a liver sample so her liver storage of vitamin A could be deter- mined. This precluded the possibility of producing a fourth litter with the gilt fed an adequate amount of vitamin A to see if this would prevent further abortions. lhile there is no conclusive evidence, it is recog- nized that the fetal deaths in these 2 litters may have been a result of the low vitamin A intake. One other abnormality was observed. The second pig born in the second litter of gilt 12 (group III), was born with an extra toe on its left front foot. Subsequent X-ray and dissection examination revealed the radius of the affected leg was also completely missing. The ulna appeared to be normal, but the distal end of the lateral condyle of the humerus seemed thickened and flattened. Since this was an isolated de- formity which occurred only in this one pig, it cannot be attributed de- finitely to lack of vitamin A; neither can deficiency of vitamin A, as a possible cause, be ruled out. There were no other gross abnormalities found, either externally or internally, in any of the baby pigs born to any of the 5 groups. All of the pigs born in the first litters were strong, healthy and vigorous at birth. This was also true for all but one of the litters born after the -57.. second gestation period. In litter 87 from gilt 12 (group III), the first 6 pigs born were weak in comparison to average newborn pigs. This litter was born on a very cold night in November and the pigs which were returned to the mother were all found dead the next morning. Apparently they had become chilled and died from the cold. Because of this, no comparison of the survival rates between the weak and strong pigs was possible. Thus, in summarizing the reproductive performance, there were some indications that the level of 2.5 micrograms of supplemental vitamin A per kilogram of body weight daily may have been inadequate to support normal reproduction. Further work is required before definite conclusions can be drawn for these manifestations did not occur uniformly in the gilts fed the low level of vitamin A and may have been due to undetermined causes. Milk Vitamin A Content Newborn pigs from sows on normal gestation rations have been found to have relatively low vitamin A stores at birth. It has been generally considered that these stores, while of benefit to the piglet, are inade- quate to sustain his needs for any appreciable length of time, especially when the very rapid growth of the young pig is also considered. The mother's colostrum and milk provide substantial amounts of vitamin A to supplement the meager stores present at birth. Because of this the effects of the levels of vitamin A fed to the gilts during gestation upon the vit- amin A content of their milk could be of appreciable importance. Therefore, samples of milk were obtained at birth and at intervals during the first week post-partum. The levels of vitamin A found in the milk samples are listed in table 9. The levels of vitamin A found in the colostrum at birth, and in the .eoaaaao masquuaaaa .pnwaa pupae some swam .o .mswroahmm seams muouuwa uomsmou madam .p .zouumu no: can .m mm mm no em a ma mm as .m>< Mm mm me am an a mmm ma 0 a m 0H an em ea 0 mm a as mm sma ma mm 0: so we as ea wn mm Ha . HHH means as cm mm mm .m>< . a a m mm mm oa my , a ma am mm mm m . a ma mm m: om w em «N no :ma n nna a 9 am m HH anonc a .2 5 w m m Wm E .3 am maa mm mwa a m a: sma and mmm om on mm and e a ma mm as omm m an we was man mm ma we now H . Houusoo - .uua wed .oun ms .mun em sauna .mua mod .uua mm .nna em sauna sass coauauoaa vacuum coauauoua sauna Ada 00fi\.woav quz ho azwazoo < sz .¢ mqm mo omsmu as» consumed momomusoAma cw momswwh .n .moowaoa coaumumow neon a“ souamw 0» ooawmu ma use N muHHo .m Am.OIN.ov m.o Am.HI:.ov w.o .mbm macaw Am.onm.ov m.o u AH.Huu.ov m.o n ma 0 no.H|:.ov v.0 m :H Am.OIN.ov :.o m no.0|m.ov w.o m NH w.o H Am.HIu.ov m.fl : Ha HHH macaw an.ofilm.ov m.N .wss macho o Am.HIm.ov w.o m 0H 0 364.5 m6 m m o 3.~..m.8 a: m w Ao.:lm.HV m.N n A:.:Im.mv m.m m u o n.0H H w HH macho Gimuoé $3 8.0m..m.3 ioa .98 93.5 simuwémv 1mm n o m Am.n~um.mav 4.5H w Aw.om|:.omv m.o~ N a o Aa.m um.mv m.u m m Aw.uauo.wv m.~a m A:.~H-m.nv m.m m H Houusoo n4 .pfib .m>< voaasmm swam p< .uw> .m>< moansmm swam mama mmeuuafl vacuum muouaad «mafia A.Ew\.wosv mon zmomzmz Qua ho mm>memm < ZHZ mH>HA .OH mqm< “We: mus: elk... M4 ”ism film. I. mm mum S m.m w.u H.HH m.:H :.:H N.mH N.m H.0N m.om m ..., 2 2 to TS . Na 92 3. an mam w 8.. ad {a :4. «...: Rm 9: ES 9.: mg: a. m.m 9.0H :.HH :.NH :.NH J.MH $.0H w.wd n.NN m .3 . E ...I.. H mm Q .Is ....In E. .... .... o m mam cam new and tom EH «.8 3H n.2, .e n.wH w.:H m.:N N.u~ b.mH o.mH o.m N.MH m.NN n m.wH N.mH m.m~ o.ma b.0d m.MH 0.0H N.:H m.Hn N N.mH n.NN m.o~ n m.om m.mn w.nfl m.ma N.HN H saoausoo .on son mmxmh @333 wm\..\~a mmkqaa mm\m~\oa R\m\3 Rxnmk RRSW RENE. 38 2.. 8<.m25 2.ch was ac mafia < 2:5: «:95 .a mama. anemia. 636 .333 .o .zonnmu ac: can .0 .mwmhdsas magmas pnOH sodasdm .n .hafimu unuwo: been mx\wos m.N I HHH means use ”was m I HH aaouc "won ma I Hoaaaoo “exsvnw < .ufi> huduofin .s as ch mm mm mm H E MN. mm .... o.o~ w.oa H.m~ 0.:m s m.:a w.m~ a.ma m.aa ma 6 ~.mm :.m~ n.am m.om H.m~ m.m~ :.n~ m.- ea c ~.ma m.n~ m.e~ o m.aa m.oa ¢.ma m.m ma u s.m~ w.mm m.- m.HH m.ma ~.ma ~.aa n.a ma ~.w~ e.a~ m.nm m.m~ w.ma m.ma m.ma s.ma a HH cHHH means I m.~m m.m~ m.m~ 5.:H e.sa w.ma m.ma a.:H .w>< . mm .odm mm. «mm 3 mm .m.|m m S . c ~.m~ w.n~ m.mm m.wa a.aa o.- m.ma m.ma 0 mm o H.6H m.w~ n.m~ a :.oa s.ma m.ma ~.ma m . a.m~ :.m~ ¢.mm w.mm c o.wa w.ma m.oa o.aa a o s.o~ w.a~ o.H~ a w.o~ w.m~ e.ma w.na m sHH muons .....I. Fe Fe mm .... mm mil. H... mm .... :.om m.sa o.m~ n.m~ o H.o~ a.wa m.ma m ~.Hm m.- m.am m.mm H.mm w.ma o.:~ :.ma H.o~ : o w.w~ m.wa m.s~ a.om m.wa m.am m.sa :.ma n o m.am a.mm a o w.ea o.a~ ~.:H a.ma w a.nm m.s~ ~.m~ w.w~ H.o~ m.mm H.m~ H.o~ m.- a snoauaoo .0: now schema: sew mm\m~\aa mmxmmxm mn\:H\w scaccc: can mm\n~\: mm\am\m om\a~\~ mn\an\a onus AQHQZHBZOOV .H mqm<8 anszm< APPENDIX TABLE 2. - s5 - CONTROL LITTERS: WEIGHTS, LIVER VITAMIN A (mcg./gm.). AND PLASMA VITAMIN A Glcg./100 m1) Birth Weight Liver Plasma vit. A Pig no. weight 0 1 wk. vit. A birth 24 hrs 72 hrs 168 hrs Litter 61, Dan 3, Born 5/12/59 1 ' 3.4 7.1 18.0 28.2 28.8 35.1 2 3.2 7.2 13.0 33.1 27.6 33.1 3 2.9 7.52 16.0 4 3.3 9.12 15.8 5 2.4 5.0 15.2 36.2 29.6 36.8 6 2.1 6.06 19.4 7 2.4 5.1 22.6 32.8 28.4 29.6 8 1.9 4.1 22.1 17.2 29.3 39.0 9 1.5 5.47 24.8 10 2.1 7.58 23.2 11a 2.0 12b 2.2 4.1 24.0 28.4 40.3 13b 3.4 6.4 25.4 29.3 32.0 Litter 62, mm 1, Born 5/18/59 1 3.5 6.2 23.0 21.3 18.2 24.8 2 3.2 10.31 26.2 3 2.9 5.0 23.0 22.4 19.4 27.0 4 2.9 5.1 24.0 25.4 20.4 25.7 5 3.3 11.30 22.4' 6 2.8 7.39 21.8 7 3.2 5.8 ‘ 16.8 23.5 20.2 27.9 8 2.9 12.40 13.6 9 2.2 4.4 8.0 23.0 17.2 24.0 10 2.0 7.63 16.3 11 2.2 2.3° 17.2 20.7 19.9 24.0 12 1.6 3.2 16.3 16.3 21.0 21.6 13 2.1 8.64 22.1 148 3.0 7 a. Born dead. b. Born late—after gilt had apparently finished farrowing. Ce Injured by gilt--1ater died. APPENDIX TABLE 2. (CONTINUED) Birth Weight Liver Pflasma vit. A Pig no. weight 0 1 wk. vit. A birth 24 hrs 72 hrs 168 hrs ' Litter 66, Dan 4, Born 5/30/59 1 3.3 7.3 17.4 24.6 22.4 24.3 2 2.2 5.2 15.6 19.6 27.6 25.2 3 3.4 20.38 18.5 4 3.1 20.79 16.3 5‘ 3.3 Litter 82, Dam 1, Born 10/27/59 1 3.1 5.8 17.2 24.0 31.0 34.2 2 2.9 2.8b 15.8 26.8 19.9 27.0 3 2.5 12.15 16.3 4 2.2 10.08 17.2 5 2.2 5.5 19.5 23.5 27.4 26.8 6 2.8 5.5 13.8 25.4 32.3 28.2 7 2.2 7.97 16.0 8° 3.1 19.0 9 3.1 17.77 21.2 10 2.3 . 14.48 a 11 2.5 3.8 11.9 22.6 29.0 27.4 12 2.1 13.32 18.0 13 2.4 4.9 18.2 23.5 29.3 31.8 143 2.9 Litter 84, Dam 5, Born 11/2/59 1 3.3 6.3 25.2 29.8 38.1 31.8 2 4.0 21.76 24.6 3 3.9 5.8 25.4 27.6 30.1' 32.6 4 2.4 5.2 23.0 30.4 38.6 36.2 5 3.2 24.56 27.4 6 3.2 6.4 22.1 32.6 27.4 33.? 7 3.5 22.98 24.3 a. Born dead. b. Runt pig--1ater died. c. d. Died during first night. Sample lost during analysis. -87- APPENDIX TABLE 2. (CONTINUED) Birth Weight Liver Plgggg vit. A Pig no. weight 0 1 wk. vit. A birth 24 hrs 72 hrs 168 hrs Litter 86, Dam 4, Born 11/15/59 1 3.1 5.8 25.2 30.4 34.6 33.7 2 3.1 17.44 24.0 3 3.2 5.1 26.8 32.3 34.6 32.3 4 1.9 12.23 26.0 5 3.0 4.6 25.2 28.4 32.3 24.6 6 3.1 4.8 26.5 30.6 28.4 32.8 7 2.7 18.44 15.8 4 8 2.9 23.66 21.8 9 3.2 3.6 22.6 31.8 a 30.1 10 2.9 14.40 24.3 11 2.5 4.6 26.0 32.8 29.3 34.6 12 2.9 18.20 15.8 13 3.1 5.6 23.5 34.6 32.8 35.9 Sample lost during analysis. APPENDIX TABLE 3. Birth GROUP 11 LITTERS: WEIGHTS, LIVER VITAMIN A (mcg./gm.), AND PLASMA VITAMIN A (mcg./100 ml) Weight Liver Plasma vit. A Pig no. weight 0 1 wk. vit. A birth 24 hrs 72 hrs 168 hrs Litter 60, Dan 9. Born 5/9/59 1 3.3 6.4 11.0 26.0 25.2 25.4 2 3.5 8.27 6.4 3 3.2 5.0 16.6 25.5 21.8 25.4 4 3.5 7.3 20.4 24.3 21.8 20.7 5 2.9 4.13 21.0 6a 3.0 5.9 21.8 24.6 22.4 Litter 63. Dan 6, Born 5/19/59b 1 3.9 18.2 2 3.1 c 3 3.5 10.66 17.2 4‘ 3.2 17.7 Litter 65, Dan 7, Born 5/30/59d 1 3.1 6.6 15.0 19.0 22.6 19.9 2 2.9 4.8 12.4 23.2 24.6 19.4 3 3.1 4.41 13.3 4 1.6 3.28 14.4 . 5 2.8 6.1 11.9 21.6 20.2 17.7 6 3.2 3.40 16.3 7 3.0 4.8 18.0 22.4 15.0 26.8 8 3.9 6.6 20.2 22.4 21.0 24.3 9 3.1 2.98 15.0 10 3.8 7.6 17.2 26.8 23.5 35.1 11 3.1 2.53 21.3 12° 2.5 ‘ Litter 67, Dam 10, Born 6/3/59 1 3.4 0.60 c 2 , 3.4 1.54 17.2 3 2.8 0.65 20.4 a. b. Cs Born late-after gilt had apparently finished farrowing. Gilt refused litter-oall died. Samples lost during analysis. Gilt refused litter-pigs raised by gilt 4. Born dead. (CONTINUED) Weight APPENDIX TABLE 3. Birth Liver Plasma vit. A Pig no. weight 0 1 wk. vit. A birth 24 hrs 72 hrs 168 hrs Litter 67, Dam 10, Born 6/3/59 (Cont.) 4 3.9 7.9 17.4 29.3 28.2 23.5 5 2.5 0.71 19.4 6 3.4 7.6 17.4 25.7 25.2 31.0‘ 7 3.6 7.6 21.0 25.4 26.0 23.5 8 3.4 7.2 25.7 20.4 26.8 15.8 9 3.1 7.2 20.4 26.8 29.0 20.2 10 2.9 7.1 16.6 28.4 28.2 21.8 11 3.6 . 0.65 23.8 Litter 68, Dan 8, Born 6/6/59 1 3.4 7.2 17.2 27.4 19.4 18.0 2 3.6 6.5 9.7 15.8 18.5 27.4 3 3.2 2.11 17.3 4 3.4 7.0 13.6 a 16.6 23.2 5 3.6 2.12 12.2 6 2.1 0.72 18.5 7 3.2 5.2 13.6 18.5 15.0 21.3 8 2.1 1.30 15.2 9 2.8 6.9 15.8 19.6 19.0 21.3 10 3.2 6.1 16.3 21.3 22.4 20.7 11 3.1 2.35 18.0 12 3.6 Litter 83, Dam 7, Born 11/1/59 1 2.8 5.9 31.0 32.3 . 29.8 22.6 2 2.8 2.42 26.2 3 3.4 4.2 24.0 35.5 48.7 19.9 4 2.8 4.7 20.5 35.0 34.5 a 5 3.2 4.01 21.8 ,6 2.8 3.5 31.0 35.6 33.2 19.4 7 3.4 2.68 a a. b. Samples lost during analysis. Born dead. -90- APPENDIX TABLE 3. (CONTINUED) Birth Weight Liver Plasma vit. A Pig no. weight @ 1 wk. vit. A birth' 24 hrs 72 hrs 168 hrs Litter 83, Dam 7, Born 11/1/59 (Cont.) 2.1 1.16 35.4 2.6 a 31.0 33.7 10 3.1 2.06 26.0 11 3.3 5.1 33.2 27.4 29.8 a. Pig died 11/3/59. APPENDIX TABLE 4. - 91 - GROUP 111 LITTERS: WEIGHTS, LIVER VITAMIN A (mcg./gm.), AND PLASMA VITAMIN A (meg./100 ml) Birth Weight Liver Plasma vit. A Pig no. weight @ 1 wk. vit. A birth 24 hrs 72 hrs 168 hrs Litter 59, Dam 11, Born 5/8/59 1 3.1 '7.2' 6.8 19.6 19.0 16.8 2 2.9 1.6 9.4 3 2.9 5.5 14.1 19.0 21.3 15.5 4 2.8 5.9 12.7 21.3 ' 20.4 17.2 5 2.9 0.74 17.2 6 3.2 1.22 7.8 7 2.4 1.36 8.8 8 2.2 3.6 11.0 13.0 16.3 14.6 9 3.2' 6.0 15.0 13.0 20.4 14.1 10 3.6 6.4 13.6 12.2 23.5 18.5 118 2.4 12b 3.8 7.7 26.0 19.6 23.5 Litter 64, Dan 15, Born 5/24/59° 1 3.5 1.11 21.0 2 3.3 3 3.8 0.96 19.9 4 3.6 1.02 18.5 5 3.6 0.91 19.6 6 ' 3.1 16.6 7 3.4 19.4 Litter 69, Dam 12. Born 5/25/59 1 3.4 6.2 19.0 18.8 21.0 15.0 2 2.5 0.60 19.4 3 3.2 5.3 ' 15.6 21.8 17.2 15.8 4 2.6 4.8 13.6 20.2 18.0 25.2 5 2.9 0.48 13.6 6 2.3 4.2 14.4 18.0 17.2 23.2 7 3.6 0.64 15.5 8 1.8 0.62 19.0 a. Born dead. b. Born late-after gilt apparently had finished farrowing. Co Gilt refused pigs-411 died. - 92 - APPENDIX TABLE 4. (CONTINUED) “ Birth Weight Liver Plasma vit. A L Pig no. weight @ 1 wk. vit. A birth 24 hrs 72 hrs 168 hrs Litter 69, Dam 12, 5/25/59 (Cont.) 9 3.5 6.2 18.0 19.4 18.0 13.0 10 3.6 0.53 16.3 Litter 72, Dam 14, Born 5/23/59 1 3.7 5.4 11.0 11.0 23.2 16.0 2 2.3 0.48 12.4 3 2.9 0.95 13.6 4 2.7. 0.61 12.4 5 - 3.0 5.6 13.0 15.5 23.8 21.3 6 3.1 0.46 17.2 7 3.5 0.42 13.6 8 2.8 0.44 23.3 9 3.3 6.0 10.8 11.9' 25.7 15.6 10 3.5 5.8 10.0 13.8 8.8 12.4 11 2.8 6.0 6.1 13.0 13.6 8.3 12 3.3 4.6 8.6 18.5 13.6 14.1 Litter 81. Dam 15, Born 10/22/59 1 3.2 6.8 17.2 a 17.2 24.8 2 3.2 0.46 18.0 3b 2.1 21.6 4 3.4 6.5 21.3 23.0 22.1 21.6 5 2.8 0.22 18.5 6 3.4 6.5 21.8 21.8 24.3 23.2 7 3.1 0.25 a 8 3.2 0.20 a 9 1.8 0.15 17.4 10 2.6 5.9 20.4 21.3 26.0 19.4 11c 1.9 0.33 12b 3.6 0.31 13° 3.6 as be Ce Samples lost during analysis. Killed by gilt. Born dead. APPENDIX TABLE 4. - 93 (CONTINUED) Birth Weight Liver Plasma vit. A Pig no. weight @ 1 wk. vit. A birth 24 hrs 72 hrs 168 hrs Litter 85, Dam 11, Born 11/6/59a l 3.4 5.9 16.0 26.5 31.8 29.8 2 3.6 4.6 20.7 22.4 28.2 23.5 3 ' 2.8 0.61 Litter 87, Dam 12, Born 11/17/59b l 2.4 0.27 21.0 2 1.9 0.24 24.0 3 2.4 24.6 4 2.5 25.4 5 2.8 23.8 6 1.8 0.45 12.4 7 2.8 19.4 8 1.4 17.7 9 2.8 0.36 20.4 10 2.? 16.8 11 3.2 0.48 18.2 12 2.9 23.0 130 2.5 a. Nine partially resorbed fetuses-2 to 3 inches long. b. All pigs died first night--apparent1y chilled. Ce Born dead. ROOM USE ONLY ROOM USE GNU! STATE UN HIII “WWWWWW 3 0 8 5 O 7 4 1 1293 0 "11111