For Reference NOT TO BE TAKEN FROM THIS ROOM ©X UBBIS mmm aismsiKSJS University of Albnta Printing Department Digitized by the Internet Archive in 2018 with funding from University of Alberta Libraries https://archive.org/details/solventextractedOOjohn THE UNIVERSITY OF ALBERTA SOLVENT -EXTRACTED RAPESEED OIL MEAL AS A PROTEIN SOURCE FOR PIGS AND RATS by JOHN GERALD MANNS A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE DEPARTMENT OF ANIMAL SCIENCE EDMONTON, ALBERTA SEPTEMBER, 1962 ABSTRACT Four experiments were designed to study the addition of Polish- type solvent-extracted rapeseed oil meal to diets for pigs and rats. Rapeseed oil meal was incorporated into the rations at three different levels on an equivalent protein basis at the expense of soybean oil meal; one diet high in rapeseed oil meal was supplied with additional supplemental lysine. Pigs and rats had decreased rates of gain and lowered efficiencies of food utilization in the starter and grower periods as the levels of rapeseed oil meal in the diets increased. During the finisher period no ration effect was evident with either species. Individually-fed pigs were less affected than group-fed animals, probably because of a lower feed intake, and thus a lower goitrogen intake per unit of body weight, by the former animals. No significant ration effects were observed on carcass characteristics of pigs at any level of rapeseed oil meal. Pigs did tend to have longer carcasses and smaller areas of loin as the percentage of rapeseed oil meal increased. Female rats conceived normally but fetal resorptions and still¬ births were prevalent on the rapeseed oil meal diets. There was evidence of impaired conception in gilts fed high levels of rapeseed oil meal. Liveability was poor and weaning weights were low with both pigs and rats when rapeseed oil meal was a dietary constituent. These results suggest that rapeseed oil meal should be used judiciously in reproduction rations or in rations for pigs to be kept for breeding purposes. Digestibility coefficients for nitrogen, energy and dry matter tended to decrease as the levels of rapeseed oil meal increased, although ; i_. . . > . jjj - - - • . - . . - this effect was significant only with rats. The addition of lysine to the experimental diets may have been responsible for improved digesti¬ bility coefficients with pigs but the rat data did not confirm this observation. Nitrogen retention was significantly lowered when high levels of rapeseed oil meal were fed to rats. Blood serum protein-bound iodine and standard metabolic rates were used as criteria of thyroidal activity. Rat serum protein-bound iodine levels were not affected by the rapeseed oil meal goitrogen although a significant reduction in protein-bound iodine was noted with pigs fed high levels of rapeseed oil meal. Standard metabolic rates in 5 week old rats were reduced by the high levels of rapeseed oil meal feeding . Thyroid gland hypertrophy and histological disturbances were evident with rats at 5 and 6 weeks of age on the high rapeseed oil meal diets. When rats were 12 weeks of age however, the glands seemed to be functioning normally. Weights and histological sections of thyroid glands of pigs at market weight or older did not indicate serious malfunction. Adrenals and livers from rats at 12 weeks of age and following reproduction showed no gross abnormalities. Livers from swine on high levels of rapeseed oil meal showed a moderate degree of hypertrophy . : ACKNOWLEDGMENTS The writer wishes to thank Dr. L. W. McElroy, Head of the Department of Animal Science, for placing the facilities of the Department at his disposal. The assistance and guidance of Dr. J. P. Bowland, Professor of Animal Husbandry, throughout the course of this study, and his con¬ structive criticisms and suggestions for the improvement of this manuscript are gratefully acknowledged. The writer is also indebted to Dr . V. E. Mendel, Assistant Professor of Animal Husbandry for supervising the preparation of the histological tissue sections. The assistance of Mr. G. Stephens, swine herdsman at the University Livestock Farm, who cared for the experimental swine is greatly appreciated. The rapeseed oil meal used in the study was supplied through the courtesy of Federated Cooperatives Ltd., Edmonton, Alberta. This work was supported in part by a grant from the National Research Council of Canada . TABLE OF CONTENTS Page INTRODUCTION - 1 REVIEW OF LITERATURE - 3 A. Presence of a Toxic Factor (or Factors) - 3 B. Mode of Action of the Toxic Factor (or Factors) - 6 C. Nutritional Value of Rapeseed Oil Meal - 9 D. Carcass Characteristics - 11 E. Gestation and Lactation - 12 EXPERIMENTAL - 15 OBJECTIVE - 15 METHODS AND PROCEDURES - 15 A. Formulation of Experimental Rations - 15 B. Methods and Procedures in Swine Experiments - 16 (a) Growth Experiments - 19 1. Individual-Feeding Trials - 19 2. Group-Feeding Trials - 19 (b) Reproduction - 20 (c) Digestibility and Retention Studies and Methods of Analysis - 21 (d) Blood Serum Protein-Bound Iodine - 22 (e) Organ and Tissue Studies - 23 C. Methods and Procedures in Rat Experiments - 23 (a) Growth Experiments - 24 1 . Experiment 1A - 24 2. Experiment IB - 24 (b) Reproduction - 25 (c) Digestibility and Retention Studies 25 .. ' - - ... . J .. .:..J - ' - • . (d) Standard Metabolic Rates 26 (e) Blood Serum Protein-Bound Iodine - 27 (f) Organ and Tissue Studies - 28 D. Statistical Analysis - 28 RESULTS AND DISCUSSION - - - 29 A. Rate of Gain, Food Consumption and Efficiency of Food Utilization - 29 (a) Starter Period - 29 (b) Grower Period - 31 (c) Finisher Period - 32 (d) Summary of the Overall Period of Growth - 33 B. Carcass Characteristics - 41 C. Reproduction - 43 D. Digestibility and Retention Studies - 47 (a) Swine Studies - 47 (b) Rat Studies - 49 E. Blood Serum Protein-Bound Iodine - 53 F. Thyroid Gland Morphology - 54 G. Standard Metabolic Rates - 56 H. Liver and Adrenal Weights - 60 SUMMARY AND CONCLUSIONS - 65 BIBLIOGRAPHY 68 - ■ a. : - c a .V — • .. - I - ~~ LIST OF TABLES Table Page 1 Formulation and Composition of Basal Rations for Lot 1 in Rapeseed Oil Meal Experiments - 17 2 Rapeseed Oil Meal as a Percent of the Total Ration - 18 3 Comparison of the Two Batches of Rapeseed Oil Meal Used in Experiments - 18 4 Breeding Schedule for Gilts and Boars, Experiment 356 - 20 5 Rate of Gain, Feed Consumption and Efficiency of Feed Utilization Individually-Fed Pigs, Experiment 356 - 37 6 Rate of Gain, Feed Consumption and Efficiency of Feed Utilization Group-Fed Pigs, Experiment 356A - 38 7 Rate of Gain, Food Consumption and Efficiency of Food Utilization Rat Experiment 1A - 39 8 Rate of Gain, Food Consumption and Efficiency of Food Utilization Rat Experiment IB - 40 9 Carcass Characteristics of Group-Fed Pigs, Experi¬ ment 356A, and Probed Backfat Thickness of Individually-Fed Pigs, Experiment 356 - 42 10 Reproductive Performance of Pigs in Experiment 356 and of Rats in Experiment 1A - 46 11 Nitrogen, Energy and Dry Matter Digestibility Individually-Fed Pigs, Experiment 356 - 51 12 Nitrogen, Energy and Dry Matter Digestibility and Nitrogen Retention Rat Experiment 1A - 52 13 Glandular Weights, Blood Serum Protein-Bound Iodine and Standard Metabolic Rates Rat Experiment 1A - 62 14 Thyroid Weights and Standard Metabolic Rates Rat Experiment IB - 63 15 Blood Serum Protein-Bound Iodine; Liver and Thyroid Weights of Group-Fed Pigs Experiment 356A - 64 . . .. - . :ir,. . - ... b- ■ -u: rj , 3 q« LIST OF FIGURES Figure Page 1 Apparatus for Standard Metabolic Rate Determinations 27 2 Growth Curves for Male Weanling Rats Fed Various Levels of R.O.M. for a Period of 9 Weeks - 35 3 Growth Curves for Female Weanling Rats Fed Various Levels of R.O.M. for a Period of 9 Weeks - 36 4 Rat Experiment IB Thyroid Photomicrographs, 2 Weeks on Trial - 57 5 Rat Experiment IB Thyroid Photomicrographs, 3 Weeks on Trial - 58 6 Rat Experiment IB Thyroid Photomicrographs, 9 Weeks on Trial - 59 ■'..v. -■ :: • ■ • • . •» . INTRODUCTION Rapeseed production in Western Canada has enjoyed a dramatic production increase during the past several years and now ranks as an important farm industry. Accelerated foreign demands have been partially responsible for the increased production but large quanti¬ ties of rapeseed are processed in Canada, primarily as a source of oil . A byproduct of the extraction process is rapeseed oil meal'*' which according to present specifications of the Canadian Feeding Stuffs Act and Regulations (1952) cannot be incorporated into com¬ mercial rations for breeding stock or into starting rations for pigs. R.O.M. may be used as only 257. of the total supplemental protein for other classes of pigs. Recorded information on the nutritional value of R.O.M. for various species of livestock is not extensive, although the scien¬ tific literature is replete with evidence that members of the genus Brassica have a marked goitrogenic effect. Morrison (1959) estimated the protein digestibility coefficient of R.O.M. to be 857o but unpal- atability and amino acid deficiencies of the meal have been reported. These factors, coupled with the aforementioned thyrotoxicity , have cast some doubt upon extensive usage of this material as a livestock feed. In view of the economic importance of rapeseed production to growers and oil seed processors, and the possibility of a relatively inexpensive home-grown protein supplement for livestock, considerably ■*"In the interests of brevity R.O.M. is subsequently used to designate the byproduct obtained during the extraction of oil from various kinds of rapeseed. Polish- type rapeseed oil meal (Brassica campestris L.) was used in the current study. . . - : •• >i- S , . . .. .1 J 3c. ,f 2 more information should be obtained concerning the use and limitations of this byproduct. In Canadian studies of R.O.M. up to 1961, a meal produced by the expeller process was tested. Now that a solvent-extracted R.O.M. has become available, the need to reevaluate the use of this meal for pigs has arisen. Complementary studies with rats were carried out to substantiate the data obtained from the swine experiments. .. I,'. . . - . j. ... . . .. . - • - •' . ■ ••• 1 3 REVIEW OF LITERATURE Bell (1955) in his excellent review article concerning the nutritive value of R.O.M. indicated that the first North American report on the feeding value of this byproduct of the vegetable oil industry appeared in 1944. In Germany, however, Morrison (1959) states that "it has long been used for stock" although it must be "fed carefully to avoid injurious results". Bell (1955) reported that published German experiments on the subject date back to 1872 although the most conclusive studies regarding the chemical composi¬ tion and nature of the goitrogenic factors present in R.O.M. have appeared in the last two decades. A. Presence of a Toxic-*- Factor (or Factors) Bell (1955) referred to the identification by Sjollema in 1901 of crotonylisothiocyanate as a constituent of the essential oil fraction of rapeseed. In 1920 Viehoever td: ad., (cited by Bell 1955) found crotonyl and allylisothiocyanate to be present in rape and mustard seed and estimated their relative toxicities with rabbits. Both Astwood jd: ad.. (1949) and Carrol (1949) isolated a goitrogenic substance from Brassica seeds, including rapeseed. This substance was later proved to be L-5-vinyl- 2- thiooxazolidone and was synthesized in 1950. In 1949 Matet £t al. (cited by Bell 1955) isolated the gluco- sides sinigrin and gluconapin from rapeseed; these substances being precursors to allyl and crotonyl isothiocyanates. Allylcarbinyl isothiocyanate (3-butenyl isothiocyanate) is the main mustard oil in rhe term "toxic" as used in this manuscript means production of vary¬ ing degrees of abnormality with respect to body growth, thyroid size and / or its histology and several other disturbances of tissues or functions. - - - ... - .. . : : j. ' - . - - - . . . ... _ . ... -. JL = - - -- \ 4 R.O.M. and Pitt-Rivers (1950) suggested that this compound might be converted by oxidation, possibly with the aid of an enzyme, to L-5-vinyl-2-thiooxazolidone. Obvious hypertrophy of thyroid glands of rats fed rapeseed was reported by Kennedy and Purves (1941). Pettit et al. (1944) observed that while 14% R.O.M. in chick starters was satisfactory, a level of 207c resulted in a high mortality rate. Blakely and Anderson (1948) reported hyperplastic goitres in turkey poults fed 207o R.O.M. and Bell (1955) states that Turner found marked goitre and growth de¬ pression in chicks fed diets containing up to 407> R.O.M. Dow and Allen (1952) reported thyroid hyperplasia but this was accompanied by accelerated body weight gain and improved efficiency of feed utili¬ zation with young chicks fed R.O.M. at levels as high as 257> of the total diet. Bell and Williams (1953) working with mice, observed growth depression when various levels of R.O.M. were added to the diet. Hussar and Bowland (1959) fed R.O.M. at 2 and 107> levels of the ration to swine and rats and observed consistent reduction in liveweight gains at the 107o level although the results were quite variable at the 270 level. Histological studies revealed characteristic thyroid abnormal¬ ities thereby further confirming the goitrogenic action of the meal with these species. Renner ^t ad.. (1955) observed that Argentine- type rapeseed exhib¬ ited a greater goitrogenic effect than the Polish-type when this meal was fed to chicks. Clandinin (1959) confirmed these findings with chicks although Bell (1957) reported no difference between these two : - .... j i - - X • \ VV. — > .. ... I • ^ ~ J . : . i' .. . . . * • • ^ c .. j. j 5 varieties when fed to mice even though the Argentine type contained a higher level of goitrogen. Clandinin £t al. (1959) reported that isothiocyanate content was markedly affected by variety although no consistent effect of location of growth was observed. Thiooxazolidone content was not only affected by variety but also appeared to be influenced by the environmental conditions under which the seed was grown. Bell ej: al.^ (1960) found that as well as having widely diver¬ gent absolute quantities of isothiocyanate and thiooxazolidone, the relative proportions of each in rapeseed varied according to variety, season and location. Using purified preparations of these two com¬ pounds Bell et a_l. (1960) found them to be about equal in toxicity in mice. Levels of 0.27, of isothiocyanate or thiooxazolidone caused some mortality while levels of 0.08% resulted in severe growth depression. These results, coupled with the Tn vitro conversion of thiocyanate to the thiooxazolidone demonstrated by Clandinin _et al. (1959) , tend to confirm Pitt-Rivers suggestion that this transformation can also occur in vivo. Evidence has also been accumulated by another route to verify the presence of a toxic factor(s) in R.O.M. Allen and Dow (1952), following the report of Astwood et ad.. (1949) that the active principle was water soluble, noted a marked decrease in toxicity when the R.O.M. was fed to chicks subsequent to hot water extraction. These workers (1954) found that any residual toxicity could be alleviated by iodine Private communication. A summary of these results are given in the Minutes of the Associate Committee on Animal Nutrition. I o . . ■ -- . . — . ■ . ..... ,r • . ^ i z, ; .. . - ...L i .. ... - . . . . _ - .. : x . X . . .. . j z . ' . . _ _ I . .. ■ - ... . . .. - . ll . . a- J .. v . ; Jj. . -Z . : i 1 .. ... - . j....' la c \ / l . J; , -- : . i . .. -ii ' o .. -j ‘ . . . . . j'.i i . ... . : - : .. . ■ ■ - .. . .. • . . a j , . 7 Hussar and Bowland (1959) reported a decrease of over 3007> in body weight to thyroid gland weight ratio when R.O.M. was fed at a 107o level to swine; histological studies also showed an increase in cellular components. These workers noted with rats that there was a decreased level of I per unit thyroid gland as the R.O.M. increased. This was taken to denote either a reduced uptake or more rapid turn¬ over rate of I-^l. The ratio of radioactive iodine in the thyroid gland to radioactive blood serum protein-bound iodine declined as the level of R.O.M. increased, thereby indicating that abnormalities and biological disturbances of sufficient magnitude to effect hormone biosynthesis had occurred. Astwood (1949) concluded that the mechanism of goitrogenesis from rapeseed is similar to the sulphonomides and thioureas, that is, the primary effect is one of thyroid inhibition. This interference with thyroxine synthesis results in a concomitant increase in thyro¬ tropin synthesis which in turn leads to hyperplasia. Greep (1954) proposed that a possible mode of thyroidal inter¬ ference by antithyroidal drugs is the blockage of protein iodination of amino acid derivitives in the gland. This hypothesis is substanti¬ ated by increased iodine content of the gland during such a medication. Bell (1955) states that Benda showed that respiration in guinea pxg liver slices was depressed 507> by 10 molar concentrations of allylisothiocyanate and that Flichenstein and Berg demonstrated inhibi¬ tion of dehydrogenation reactions involving pyruvic, lactic, citric and succinic acids by allylisothiocyanate. - : .. : i . . . . ; . J> * ■ — . : . .. : _ . — . ..1 - ol ■ . : - . ; . ■ . .. _ . . — i- ' ... i . .. - - i ... . ' .. - . . . . - . .... . . ... . V(. . v. • 8 Tissue homogenates from rats injected with thyroxine or tri¬ iodothyronine have consistently shown elevated oxygen consumption (Reid and Kossa, 1954; Barker and Klitgaard, 1952; Boyd and Oliver, 1960.) Thiourea, however, included in tissue homogenates decreased oxygen consumption (Reid and Kossa, 1954). It is well known that hyperthyroid subjects have elevated basal metabolism and Pitt-Rivers and Tata (1959) have theorized that this effect may be due to the un¬ coupling of oxidation from phosphorylation. Thyroxine has been re¬ ported to uncouple oxidation from phosphorylation by Tapley e_t al. (1955), Tapley and Cooper (1956) and others. This being so, one would expect a decrease in the P/0 ratio (number c/)P0^ bonds: 0^ consumed) and a resultant increased basal metabolic rate attributable to inefficient trapping of energy. The mechanism of this uncoupling has been attributed to inhibition of the transhydrogenase reaction involving diphosphopryidine nucleotide and triphosphopyridine nucleo¬ tide by Solomon and Dowling (1960). Tapley (1956) reported liver mitochondrial swelling in hyperthyroid rats and felt that uncoupling of oxidative phosphorylation was due to morphological alterations of mitochondria. Allen and Dow (1954) reported normal serum protein-bound iodine values of chicks fed R.O.M. Bell^ (1957) using oxygen consumption as a measure of thyroid activity noted decreased oxygen consumption of mice fed R.O.M. Although the specific action of the R.O.M. goitrogens is not known, it seems conceivable that their action could be elicited either "''Private communication. A summary of these results is given in the Minutes of the Associate Committee on Animal Nutrition. . .: . - d.. ' ' .d\ L....: . . . --- - ~ 1 1' -■ . j..' k. - . - .. ; • - . ; . . . • . . : • . ; - .. ■ . . . . . : - . ..'I . (•; I ... ; . ) . .;i . s. . . " - - ll . - - - ■ - J. :. . ’ _ . _ . ^ . .: - . .. d : d. d d . .. . ..d . /. I . ; . .. • . B . ... . . . _ 3 .. . n ... .: . .. _. II — .. _. - • • - ......... 1 d . . „ . . . 1 j .; . ... - it . ..... ;I) ; .. .... J v _ . ... . . ; . .. - . d _ . ■ ^ .a.; j.v • J I . : v . . . i - I j. _ . . .. il. . .' ." .. ..d d. „. . oi V - - — - J — . 4 , - - A. • ' . w .. ~ . ii1 - . . ' V . . . . . _ _ i J ' J J ■ - - - ^ ~ ■ - - . . - I W J -- mJm _ . . . , .4 . „ V • ■ ....... • , . . . ... .' . .. . A-., • . . 9 directly at the cellular level as Bell (1955) suggests and/or by acting indirectly through the thyroid gland. C . Nutritional Value of Rapeseed Oil Meal Morrison (1959) reported the average analysis of R.O.M. as 33.57> crude protein, 8.17<> fat and 10.87, fibre. The crude protein digestibility coefficient of 857o reported by Morrison is within the range of 82-86 percent cited by Bell (1955). Studies to accurately appraise the nutritive value of R.O.M. are confounded to a greater or lesser extent by the presence of the goitrogenic factor(s) which puts an additional stress on the animal over and above any actual nutrition¬ al shortcomings of the meal. Klain £t al. (1956) reported that as the percentage of R.O.M. in the diet rose, chick growth decreased. This effect was ascribed to inadequacy in the amino acid, arginine. Bell (1955) compared amino acid analysis of R.O.M. with chick requirements and concluded that R.O.M., when used as the only source of protein would supply adequate levels of all essential amino acids except phenylalanine. Kratzer et al. (1954) and Dow and Allen (1954) noticed a growth response in chicks fed supplemental lysine. This contrasts with Bell's 1957 obser¬ vation that additional lysine was ineffective for mice. Clandinin (1949) analysed samples of Argentine and Polish-type R.O.M. and repor¬ ted that the protein of these meals contained 3.6 and 4.27 , of lysine respectively. Clandinin et al. (1959) felt that a lysine deficiency probably was a contributing factor to depressed growth which resulted when chicks were fed R.O.M. and cautioned that excessive amounts V - ■ : . ' . - • - - Jj. -.hi . . . 10 of heat employed during the extraction of oil from rapeseed adversely affects the nutritive value of the resulting R.O.M. by reducing the available lysine content. Hussar and Bowland (1959) reported that a 107> level of R.O.M. depressed rate of gain and in some cases efficiency of feed utilization in swine and rats. Food consumption was not adversely affected in these experiments or in work with mice (Bell, 1953) although Bezeau et al. (1960) reported unpalatability with sheep when R.O.M. was fed at a level of 30% of the ration. Using an Argentine- type R.O.M. as 10%, of the total ration for swine and rats Hussar and Bowland (1959) reported depressed apparent digestibility of dry matter, energy and nitrogen, with significant effects occurring only in rats. Retention of digestible nitrogen was unaltered. Bezeau et al. (1960) reported that at 107o of the ration R.O.M. was equal to linseed oil meal for ewes although at 30%, R.O.M. there was a decrease in the protein and energy retained. Bell (1955) reported that Burkitt et: al. found that R.O.M. could be fed to beef cattle at levels up to 2 lb. per head daily with no obvious ill effects. Allen and Dow (1952) reported that steers will tolerate it in amounts as high as 25% of the grain component of the ration. Asplund-'- (1961) found that dairy cows were not affected when R.O.M. was fed as 107> of the total dry matter intake, but at a 20% level, the cows showed a rapid decline in milk production. No deleter¬ ious effects on milk composition were noted. These observations tend Private communications. A summary of these results is given in the Minutes of the Associate Committee on Animal Nutrition. I - / .:i. .c JL X. J. - . - . ....... ■ . : : ; . - .* . . . i ? ' • i • * 11 to suggest that ruminants are less susceptible to high levels of R.O.M. than are monogastrics . Bell (1957) noted species and sex differences in response to R.O.M. Male mice appeared to be more severely affected than females. Hussar and Bowland (1959) noticed the reverse in rats and found that ovariectomy apparently reduced the increased susceptibility of the female rats. Much of the previous work on the rapeseed oil meal problem has been carried out using an expeller-extracted product. Very limited information is published comparing the recently available solvent- extracted meal with the expeller meal. Goering e_t al. (1960) compared expeller and solvent-extracted R.O.M. subsequent to an enzymatic treat¬ ment designed to remove the toxic factors. Working with rats they showed expeller-extracted meal to be inferior. On comparing a mix¬ ture of 507o soybean oil meal and 507o expeller R.O.M. with 507> soybean oil meal and 507> solvent R.O.M. , a 15% increase in growth and 107o in¬ crease in efficiency of feed utilization was observed in favour of solvent R.O.M. Bell^ (1959) compared solvent and expeller-processed R.O.M. in the diets of mice and found no significant differences in gain as a result of the different methods of processing. D . Carcass Characteristics Bell and Baker (1957) fed a diet consisting of 177o R.O.M. to mice; carcass composition indicated that the males on the R.O.M. diet tended to have more water with less fat and protein than control animals. Females did not follow the same trend. Private communications. A summary of these results is given in the Minutes of the Associate Committee on Animal Nutrition. j- . . . ' : : - . : .. ..... .... * . . . . ..) hi -.it - J . .. . .. . - - •'-•'X . 1 i x .... . . . . ... . . . - 12 Allen and Dow (1954) reported no abnormal effects on carcass quality of chickens fed 17% R.O.M. Blakely _et al . (1960) reported superior carcass scores from turkeys fed 23% whole rapeseed. Thiouracil feeding has been suggested by Pipes e_t al. (1958) as a method to induce a hypothyroid condition in cattle thereby facili¬ tating the fattening process. Bowland (1951) reported that thiouracil supplemented swine rations decreased backfat and increased area of loin in pig carcasses although these advantages were accompanied by a definite decrease in length of side. Hussar and Bowland (1959) reported a trend toward shorter carcasses from pigs receiving 107o R.O.M. although a reduced area of loin was the only characteristic that reached statistical significance. E . Gestation and Lactation Information is very limited in most species on the effect of R.O.M. on reproduction. One of the first reports was by Frolich and Haring (1937) who stated that "suckling sows can be fed daily 400 gm. dry rapeseed oil meal per sow without harm to the sow's health or growth of the young. The mustard oil of the rapeseed oil meal has no effect on breeding sows, but it is advisable to guard against digestive disturbances by supplying powdered charcoal". Lucas et al. (1958) fed rations containing thiouracil and thyro- protein to gilts and observed a significant increase in embryonic mortality in the thiouracil lot after 25 days gestation. Thiouracil fed animals had an average gestation period 10 days longer than controls and farrowed only 3.3 as compared to 8.7 pigs per litter. Bell and • • ,(• T< Q i> a 'JfJjj .. , . .. . .. - .. . . . I _ : i. . . . H . ... ; .. .c .. j - . — .... .. i . .. . : ... . . . .... . ... . ... ; . . ... . . : j- - : ...... : i 1 ... _. ..... . ... . -- 1 . \ ,i\ ' .J. . . .. . . ..... . . - . - ■ . . .. : ....... . - - - i . - ... . - . . 13 Weir (1932) reported that R.O.M. and linseed oil meal were equally good in maintaining gestation weights in ewes and improving the weight and vitality of lambs at birth as compared to a ration with no protein supplement. Bezeau ej: al. (1960) fed levels of R.O.M. up to 307o of the ration. Ewes had subnormal weight gains during the gesta¬ tion period and lambs were lighter at birth and at 6 weeks of age than control lambs were. Bell and Baker (1957) fed 307> R.O.M. to mice during gestation and lactation. They found that breeding appeared to be satisfactory and that the number of young per litter was not markedly reduced by the R.O.M. diet. Bell and Baker suggested, however, that at the 307. level of feeding, R.O.M. imposed sufficient additional stress during the lactation period to interfere with normal performance. Kennedy and Purves (1941) fed whole rapeseed as 457. of the total ration and reported a delay in development of the ovaries of immature female rats to the extent that the animals would not become pregnant until the age of 5 to 7 months rather than the normal 2 to 3 months. Jones e_t al. (1946) reported that hypothyroidism had no apparent effect on male fertility in rats and that female rats fed thiouracil for more than 100 days were not sterile although they resorbed their litters. Krohn and White (1950, Maqsood (1952) and Parrott e_t aJ.. (1960) ob¬ served that hypothyroid rats ovulated but fewer young were brought to term due to fetal resorption. The thyroid hormones, although not essential for initiation or maintenance of lactation, may be important in regulating the level of 14 milk secretion. This conclusion is based primarily on studies showing that thyroidectomy reduces, but does not abolish, milk secretion while under suitable conditions the administration of thyroxine generally induces an increase in milk secretion (Reineke, 1946; Benson and Cowie, 1957; Blaxter, 1952). Grosvenor (1961) has reported that thyroid secretion rate obtained from primiparous lactating rats during the first 14 days of lactation was 1307o more than obtained from non- lactat¬ ing females of the same age. There appeared to be a definite correla¬ tion between thyroxine secretion rate and intensity of lactation. Thyroactive compounds have been tested as lactation stimulants for swine by Davis et al. (1959), Dudley _et al. (1959), and Johnson e_t al . (1959). Johnson e_t ah (1959) reported increased growth rate of litters and attributed it to thyroid hormone. The other workers reported no response although all were unanimous in stating that the treated sows lost more weight during the lactation period. : : i .: .. .. . . ... : ... - - . j - : .... . . . .... . . -• - . . . . . ... .. _ _ .: . ... .. ' .. ■ . 1 < . . ... d . .1 ■: I . _ . .... : : . . . ... .... i d . S. z . --- id.:...::. - . . . d ; . . .. v. id .:: d :' ... . j i 1 . : . . , 1 e - . 1 .... . o: .... . . 23 advantageous because of increased speed. However, because filtration represented a possible source of iodine contamination, the second ashing was ultimately chosen as a means of eliminating residual carbon, thereby facilitating subsequent steps of the analysis. Following the addition of ceric ammonium sulfate to arsenious acid a fifteen minute reaction period was employed. Samples were read in an Evelyn Photoelectric Colorimeter-*- at half minute intervals. A 420 millimicron blue filter was used for all readings. Each sample was done in duplicate, each duplicate being split into 2 equal aliquots for the final redox reaction. This gave a total of 4 readings per sample. If satisfactory checks were not obtained additional duplicate samples were analysed. (e) Organ and Tissue Studies Thyroid glands, livers, adrenals and ovaries were collected at the Swift Canadian Packing Plant shortly after the animals from Experi¬ ment 356 and 356A had been killed by severing the jugular vein. The glands with the exception of livers were sealed in small glass jars and were taken immediately to the Animal Science Research Laboratory. Thyroid glands and livers were weighed and random portions of ovaries, 2 adrenals and thyroids were placed in Bouins Solution. Treatment of the tissues and preparation of histological sections was similar to the methods used by Hussar (1958) . C . Methods and Procedures in Rat Experiments The rat trials were set up as replications of the swine studies Made by Rubicon Company, Philadelphia, Pa. 2 Bouins Solution: 75 parts saturated solution of picric acid, 25 parts formalin, 5 parts acetic acid. ■ - - : - ■ - . . - ... J.: I . ... II -.. ... . - 24 with the hope that any information so gained would be of value in interpreting the swine data, as well as in showing species differences. For these studies, 21 day old weanling rats of the Sprague-Dawley strain were used. The R.O.M. was obtained in 2 batches and since varia¬ bility in quality of the meal seemed possible 1 batch was used in Experiment 1A, the second in Experiment IB. The pertinent data on composition of the 2 meals appears in Table 3. (a) Growth Experiments 1 . Experiment 1A Since 80 weanling rats were required for this experiment and this number could not be obtained at any one time, the rats were placed on trial in smaller balanced groups as they became available between June 9 and August 8, 1961. Each of the 8 groups of 10 rats was equalized for sex, the groups being designated by the letters A to H assigned in chronological order. Groups A and B and groups F and G remained intact and were used for reproduction studies. Five rats of each of the other groups were killed at the end of 2 weeks on trial; the remaining males and females were killed at the end of the finisher period. Following the method described by Sibbald (1957), the weanling rats were fed ad libitum the experimental diets to which they had been allotted. Food consumption and rat weights were recorded at the time of weaning and at 7 day intervals until the end of the trial. 2 . Experiment IB Forty rats were placed on experiment in April 1962 . Rats were allotted to the experimental rations in groups of 10 as in Experiment 1A. The animals were fed ad 1 ibitum, 2 rats of the same sex per cage. Individual weights were recorded at time of weaning and at 7 day . ti . - •- .. - ■ - ■ - ... . . : . . I ■ - < . ■ o 1 - . - ...... . . .. ... r, i • : • . . . ... . is . . 25 intervals until the end of the experiment. Ten rats were killed at 6 weeks of age and another 10 at 7 weeks of age; the remaining 20 were maintained on experiment until killed at the end of the finisher period. (b) Reproduction Forty rats, 20 of each sex were transferred to the reproduction ration at the end of their ninth week on trial in Experiment 1A and were kept for breeding purposes. The breeding plan was similar to the one used with pigs and outlined in Table 4 except, rather than having 1 male and 2 females per lot, there were equal numbers of each sex. (c) Digestibility and Retention Studies After a ration acclimatization period of 7 days all 80 rats in Experiment 1A were placed in metabolism cages. Feed consumption and weight gains were recorded at the beginning and end of the 1 week period. On approximately the eighteenth day of gestation 2 females from each lot were placed in the metabolism cages for 24 hours. A similar 24 hour metabolism period was planned originally for the fourteenth day of lactation but because of lactation failure in the rats this period was deleted . Prior to the start of the metabolism trials the cages were washed and sprayed with a saturated solution of boric acid in 95% ethanol. The methods of collection of feces and urine were similar to those described by Likuski (1959) . Methods of analysis for nitrogen and energy have previously been dealt with (Swine Experiments, Section (c)). - -- - ' / . , ■' . - Jiri an 26 (d) Standard'*' Metabolic Rates After 17 to 20 days on trial standard metabolic rates were measured with 40 rats from Experiment 1A, thereby giving a total of 8 rats per ration treatment. Equal numbers from each sex were used. The apparatus (Figure 1) was similar to that used by Bailey e_t a_l . (1957) . Prior to being placed in the air tight chamber in the water bath the animals, weighing 100 - 25 grams were fasted for approximately 12 hours. At the beginning of the experiment the system was flushed out with oxygen to provide an enriched atmosphere. An acclimatization period of 30 minutes was allowed in the water bath at 28 to 32° C. A desk lamp with a 30 watt bulb about 2 feet from the water bath was found to be helpful in quieting the animals and this was adopted as standard procedure. Twenty-five ml. of 107o NaOH was used to absorb exhaled carbon dioxide. Water was used in the manometer and the amount of distilled water required to equilibrate the arms in a given time period was taken to be the oxygen consumed by the rat. Final calculations were based on three 15 minute periods. The weight was adjusted to the 3/4 power of body weight as Brody (1945) and others have suggested. Twenty rats from Experiment IB were used for standard metabolic rate studies. The first group of 10 was treated as in Experiment 1A. The only difference with the second group was that instead of being 38 to 41 days of age they were 45 to 48 days old. It was hoped that by extending the period 1 week with the second group that information could ■*- The term is taken from Maynard and Loosli, 1962, Animal Nutrition, 5th Edition, McGraw-Hill Book Company, Inc., Toronto. In this study, standard metabolic rate means "The heat produced in a thermoneutral environment (28 to 32° C.) after a 12 hour fasting period." - % ' . 27 be obtained suggesting when the most drastic goitrogenic effect occurred. Figure 1. Apparatus for Standard Metabolic Rate Determinations (e) Blood Serum Protein-Bound Iodine Twenty of the 40 rats used in the standard metabolic rate determina¬ tions in Experiment 1A were allowed access to feed for 24 to 36 hours . It was felt that a recuperation period was necessary to allow the animals to readjust after the fasting period. The animals were than decapitated and blood taken for serum P.B.I. determinations. Another 20 rats were killed upon completion of the finisher period and blood was again collected for serum P.B.I. Serum separation and P.B.I. determinations were done according to the previously outlined method (Swine Experiments, Section (d)). • « 28 (f ) Organ and Tissue Studies Certain organs of the rats from Experiment 1A were excised and used for glandular studies. Ovaries, testes and adrenal glands of the 6 week old rats were taken and preserved in Bouins solution. Ovaries, testes, adrenal glands and livers of the 12 week old rats were obtained. Upon completion of the reproductive period the 20 males and 20 females used for this portion of the study were killed and adrenal glands and livers excised and weighed. A visual examination was made of the female reproductive tracts to detect gross abnormalities . Subsequent to the standard metabolic rate determinations, the rats in Experiment IB were killed and the thyroid glands removed, weighed and placed in Bouins solution. The remaining 20 rats, not involved in the standard metabolic rate studies, were killed at the age of 12 weeks. All tissues except livers were examined histologically by a method similar to that reported by Hussar (1958). D . Statistical Analysis The statistical evaluation of the data was carried out using analysis of variance as described by Goulden (1960). Duncan's Multiple Range Test (1956) was used to evaluate differences between means. In the discussion of the data in this manuscript non-significant means will be designated as. such and other differences mentioned will be understood to be statistically significant at either the 5 or 1% level. No interactions occurred between sex and ration except those that are specifically referred to in the text. -- - • - : : J V.' - . 29 RESULTS AND DISCUSSION In the interests of brevity the dietary levels of R.O.M. in the current study will be referred to as 0, 25, 50, 100 and 1007o + lysine. The reader is reminded that these are relative, not absolute values and denote only the per cent of soybean oil meal being replaced by R.O.M. in the ration (see Table 2). Levels of R.O.M. used in experiments referred to will be given as per cent of the total ration in so far as this is possible. A . Rate of Gain, Food Consumption and Efficiency of Food Utilization Because of overall similarity in design of experiments, the data from both species will be discussed simultaneously thereby facilitating between species comparisons. The results are presented in Tables 5 to 8 and Figures 2 and 3. (a) Starter Period. - 15-55 lb. liveweight for pigs in Experi¬ ment 356 and 20 - 50 lb. in Experiment 356A; 3 to 5 weeks of age for rats. Both species showed a reduction in rate of gain and, to a lesser degree, a depression in efficiency of food utilization at the 1007. levels of R.O.M. supplementation (Tables 5 to 8). When one compares the 1007o level of R.O.M. to the 0 and 257o levels, rate of gain was reduced 3570 and 157> more food was required per unit of weight gain in rats while corresponding figures for the pigs were 20 and 87> respectively. This species difference could be explained on the basis of an extremely rapid rate of gain and synthesis of body protein in the rat at this early age. A malfunctioning thyroid gland would be expected to exert a maximum effect under such conditions. At the 507> level of R.O.M. supplementation in the ration, the results were quite variable but, in general, the performance of this group was inferior to the groups receiving 0 and 257> -■ ' ■ ... - -• ■ •' ' •' ; j: . • • _ ■: - . . . . ... .... . 1 . .. ■ - :... 5: : . : .. . -- ■ • - - j - . . ; ,;j . - . .... .. . _ .. . :,J .. .. .... 30 R.O.M. when daily gain and efficiency of food utilization are the criteria of measurement. The addition of supplemental lysine in lot 5 to the animals receiving 100% R.O.M. had no influence on the rate of gain or efficiency of food utilization. The lysine requirement of growing pigs has been estimated to be 0.65% of the total diet for 20 to 70 lb. pigs receiving 16% protein rations, (N.R.C. Nutrient Requirements, 1959). The basal starter ration contained 0.82% lysine while the 100% and 100% + lysine diets contained 0.78 and 0.86% lysine respectively. On the basis of the aforementioned requirements the ineffectiveness of the supplemental lysine is not unexpected, although Kratzer et al_. (1954) and Clandinin et al . (1959) have reported R.O.M. to be low in lysine for growing chicks. Bell's (1957) results with mice are in agreement with the present findings. Low food intake, presumably associated with lack of palatability of the diets occasionally occurred with rats fed on diets high in R.O.M. If the animals were not placed on the experimental diets immediately after weaning, excessive food wastage resulted although within a few days they accepted their food readily. Bowland (1957) noted that pigs prior to weaning found R.O.M. quite unpalatable even at low levels although Hussar and Bowland (1959) found that animals ate normal levels of rations containing R.O.M. after weaning provided no alternative feed was available. Average daily feed consumption of pigs (Tables 5 and 6) was not affected by R.O.M. in the present study. Male rats grew faster than females and required less food per gram of gain. Boars and barrows grew slightly faster than gilts. These results with pigs are in agreement with Fredeen (1953), Charette (1961) ' 1 Sl . • < i. ... .... - ..... ... • ••• ... .. ' ... ■ o O - J . ... . “ M ■ • - - ' . .C f . , . ... ) ’ * * - . . 31 and others. (b) Grower Period. - 55 - 110 lb. liveweight for pigs in Experi¬ ment 356 and 50 - 110 lb. in Experiment 356A; 5 to 8 weeks of age for rats . Pigs fed ^d libitum in Experiment 356A showed significant reduc¬ tions in rate of gain on rations 3, 4 and 5 containing 50 or 100% R.O.M. although the individually- fed pigs were not similarly affected. The individually- fed animals were restricted in feed intake since they ate only 73%, of the feed consumed per day by the ad libitum fed pigs. De¬ spite this, they made 90%, of the weight gain and were therefore 20%, more efficient feed converters. Bowland (1957) and others have reported a similar increase in feed utilization when feed intake of pigs was restricted. It is possible that the greater intake of goitrogenic factor per unit body weight with the group- fed animals resulted in a more noticeable ration effect. In the rat trials, rate of gain and efficiency of food utilization were reduced by the high levels of R.O.M. although some degree of toler¬ ance appeared to be developing during the latter part of the grower period. Lysine had no significant effect on either rate of gain or efficiency of food utilization in either species. Barrows gained 0.07 lb. per day faster than gilts in Experiment 356A while boars and gilts in Experiment 356 had almost identical gains of 1.28 and 1.30 lb. per day respectively. On the basis of published work in which boars have gained faster than either gilts or barrows (Fredeen, 1953; Charette, 1961) it seems possible that at this particular stage of growth boars in Experiment 356 were affected more by the R.O.M. diets than gilts were. Barrows in lot 1 in the group-fed trials gained - i. . .x . . • • - - ; • . . . - • • ■■ . . ) - • : . . • y. . ; . - . ; . - . . ... J ... 32 0.14 lb. per day faster than gilts. This suggests a greater tolerance to the R.O.M. goitrogen by the females. Male rats grew 407. faster and required only 607. of the food to make body weight gains equal to the females . Feed intake with the individually-fed pigs declined on the 1007. levels of R.O.M. ; however, group-fed animals ate normal levels of all rations. Food consumption was not affected by levels of R.O.M. in the rat experiments. (c) Finisher Period. - 110 - 210 lb. liveweight for pigs in Experiment 356 and 110 - 195 lb. in Experiment 356A; 8 to 12 weeks of age for rats. By the beginning of the finisher period it appeared that the pigs had become tolerant to the rations high in R.O.M. and body weight gains in all 5 ration groups were similar. The same tendency was evident with the rats and ration effects were not significant in either average daily gain or efficiency of food utilization. It should be pointed out that the finisher ration contained only 9.6 as compared to 15.67, R.O.M. in the grower ration. This lowered level of R.O.M. intake may at least partially account for the improved perform¬ ance of both species of animals. Barrows fed ad libitum and individually- fed boars gained 0.13 and 0.36 lb. per day more than gilts in their respective experimental groups. Boars were 207. more efficient feed converters than gilts. Barrows and gilts did not differ in efficiency of feed utilization although barrows ate 0.37 lb. more feed per day thus accounting for the increased daily gain. These sex differences are in agreement with previously mentioned workers . ■ .. ... . . . .. . .1 ... .... . ... .../.. v , ...... ... _ ....... ; . ' ... V'l . 33 (d) Summary of the Overall Period of Growth. With both swine and rats, during the starter and grower periods, rate of gain and efficiency of food utilization decreased with increasing levels of R.O.M. above 25% of the supplemental protein. This effect was most pronounced at the 100% level of supplementation; these results are in agreement with Hussar and Bowland (1959). The 25% level of R.O.M. supplementation caused no deleterious effects on rate of gain or effici¬ ency of food utilization. The 50% level gave inconsistent results indicating that this regimen was borderline; some animals tolerated it extremely well while others were moderately to severely affected. Supplemental lysine added to the 100% R.O.M. ration did not have any consistent effect on either species. McWard e_t al_. (1959) found that with levels of 12.8 and 21.7% protein in grower rations for pigs that 5.55 and 4.38% lysine (expressed as % of the total protein in the ration) respectively gave optimum growth. A similar report by Magruder et al . (1962) indicated that the lower the level of protein in a ration the greater the proportion of lysine must be. On the basis of the N.R.C. Nutrient Requirements for Swine (1959) one would not expect to get any response from lysine in Experiments 356 and 356A. The levels of 0.78 and 0.86 in the starter and grower rations should be adequate although the 0.68% level of lysine in ration 4 of the finisher period may be borderline. In any case, the growth data in Tables 5 to 8 indicate that lysine levels in the diets were not a limiting factor. There was definite evidence of increased feed efficiency with pigs when feed intake was restricted and it is suggested that this point may be of practical significance as a means of reducing the toxicity of R.O.M. when fed at high levels . This increased efficiency of feed utilization has been previously reported by Barber et a_l . (1957) and Berg and Bowland (1958) . - .... ’ ' . ... : . • • . i * \ ■ ; 34 Barrows grew 0.06 pounds per day faster than gilts. Boars grew 0.14 pounds per day faster and were 137o more efficient feed converters than gilts in Experiment 356. Crampton and Ashton (1945), Bennett and Coles (1946) and Fredeen (1953) have reported similar sex effects. Increased efficiency of feed utilization by boars has been noted by Charette (1961) . Male rats gained 307» faster and were 187. more efficient food converters than female rats. The growth data (Tables 7 and 8 and Figures 2 and 3) do not show any clear evidence that one sex was more severely affected than the other. No statistically significant sex x ration interactions were present. Palatability was no problem with levels of R.O.M. as high as 15.67o of the total ration. Growth data and food efficiency figures indicate that despite the rather marked difference in thiooxazolidone and isothiocyanate contents of the two meals used in rat trials 1A and IB (Table 3) the value as a protein supplement has not been changed appreciably. Clandinin'*' (1962) fed these same meals to chicks and found that thyroid to body weight ratios were increased 3207> and 290% by batches 1 and 2 respectively. Body weight gains were 87» lower when chicks received 157> R.O.M. from batch 1 as compared to batch 2. This reduction in rate of gain was not so great as the thiooxazolidone and isothiocyanate con¬ tents of the meals would indicate (Table 3) and for this reason it may be that thiooxazolidone and isothiocyanate are not the only toxic factors in R.O.M. as Bell and Williams (1953) have suggested. ■'‘Private communication. .. - - ' > U - . : - .. . / ; . . . .. . ] : - . ; . ; . • • -• - ■ ; . , - •• . . - : • - * - - i . .. . - - - _v : . .. . ... .. . - .. 1 . . . 1 1 • EXPERIMENT LA EXPERIMENT IB 35 surej9 ui Time in weeks Figure 2. Growth Curves for Male Weanling Rats Fed Various Levels of R.O.M. for a Period of 9 Weeks. EXPERIMENT LA EXPERIMENT IB 36 u i SUlEjf? Figure 3. Growth Curves for Female Weanling Rats Fed Various Levels Rate of Gain, Feed Consumption and Efficiency of Feed Utilization Individually-Fed Pigs, Experiment 356^ 37 on C/5 ON 30 O CNJ m ON 03 ON 4-) vO m co CNJ CNJ o vO * rH • • • • • • • • • j/ /■» •rH o m X) m 00 o t— H pH CO rH m m »H CO o CM r— < co rH i— J CNJ vD CO <1- CNJ CM CNJ CNJ CO 03 in 00 rH m CO vO S-i m nD CNJ co vO m CNJ vD cd • • • • • • • • • o O 00 nO M3 o rH rH co O H in oo rH CO ON oa p—4 rH co rH 03 CNJ nO ON OJ »— "4 CNJ CNJ CO CNJ CM hJ + o o o o o m CM i£> oo v£3 in \D CM i — I CO r— 4 i— I CM CM CM v£> M3 in iD CO i— l r— 4 CO t— I r— 4 CM CM * - O PQ PQ in CNJ on OO 30 m rH rH 30 30 m o rH 00 rH co 00 cn rH rH CO 30 CNJ CNJ CM CM cm co iO i in O v43 r— 4 M3 CO M3 CO CO o O M3 CM o CNJ co CO 00 co m m rH <± CO CM rH m cm rH CO CM CM m CM co co O 3 co co r-- M3 < 03 00 CM 3 CO i— 1 t— 1 CN] N rH co S-4 CM CM CNJ CNJ vt co id V pm 4-1 o a c cd o cm •rH S-4 o c/3 C/3 3 J3 >N • 43 XI x • X X X X X 43 ■ - 1 43 X X 43 rH cd r- H CCS J3 rH rH rH 43 rH rH i— H o rH 4 - 1 rH CNJ rH rH 4-J • C T3 X i — 1 r— 4 rH ►J g CNJ o 43 P m o u • MOM m r—4 1 S'? •r4 M O c i — 4 G c -U d m 3 o . t •1—1 •l—l o •H U — i V ■O jd • cd 1 cd rH cd cd cd 3 CD 03^ X5 m 00 00 rH 00 j-j 00 Cm O J-I -r-l rH i— i m co Sm cd 430 3—4 • m • • • 4-1 • 4J o 43 X XI X X cd 43 > cnj to -U 03 rH 03 G X r— 4 d X rH o c X iH X G XI rH O CD C oo 2 CD • CM O •H QJ T3 •i— i QJ •H •H QJ o •rH CD 4-1 cd Sm ’rJ C3 •H 4-1 4-J ’r-4 cd QJ o o cd QJ o Sm cd QJ o •rH cd CD o C CD 43 jj CL rH 3 4J S-i 00 4-4 o •i-4 00 4-J o (D 00 mm o Sm 00 MM o cd 43 03 cd c cd CD r— 4 Sm rH CM r— 1 CD r-H o C id 4SI-T3 5^ MM •H o r— 1 PM >3 >3 CD >3 >3 CM >3 >3 •rH •M C/3 d) o ±J cd CD I 1 rH Ml Pm <— 4 rH S-4 Sm rH — J V-4 ^H rH Sm 4-J ID "r-l aj H CD c 00 S-i •H •H CD •H •H "O -a CD X XJ C/3 X XJ cd x> X) 00 Cd 03 4-1 *| — j • J3 S-i X3 3 03 •rl -a Sm X) *H 03 ^3 03-tm o E • • • • cd • • CD O • • CD c • • CD > > > 4J > > CD S-i > > CD •H > > CD > > > CD IS < < < CO < r» rMCMCO^j. “ • * •• . • * • • • ° . s • • » • • . ► 38 w X X X ON Mt (X • • • •X O on o o M3 o CM M3 o CM r-H Mt o r^ m CM r— 1 CM co 3 f— 1 m o m o Mt X • • • X o o CM o CM r— 1 CM Mt 01 CM CM Mt o Mt CQ CM p— i CM £ O •H X X ca £ 00 M3 N + m 00 CM *rl • • • rH o ao ON O ON r— 1 o CM vO ■rl o r— 1 Mt ON 00 m X 1— 1 1— 1 I— 1 CM X x 03 X 03 ON Mt X CO 00 CO o • • • ix x o 00 o rl rH m o CM CM O < rH CM Mt o MO X CM i—i CM >n in O CO c a) x •x c o 03 X ■x £ X Mt o CM Mt a) a CM Mt o m X X CM r— 1 CM f— 1 £ w X 03 £ H £ w o b0 c •rl *(—l o O X PM O T— 1 M3 a, m • • • E x CM oo o CM ON ON r— 1 CM oo D 01 CM Mt ON M3 CO co >x £ 1 o a. O 3 r— < t— 1 CM o x X < 03 O r-H M3 03 O rH M3 Pm o • • • 00 o CO ON Mt rH CM o CM Mt ON M3 Mt C r— 1 r— 1 CM *rl o3 O IX r* O • CO • 03 • • • M0 >. X • X MO mo 03 «— l 03 rH ctf X rH rH rH X X T3 X 03 X o m c i •rl XJ o 00 0) CM • • X X* w 4-J co 03 c X r-H 00 3 03 • O •rl 03 •rl X •rl Ctf 03 O Qm rH ? XJ X 00 >x o C Ctf 03 r-H 6-2 IX •rl O r-1 PM >N >N o -U ctf > > > X > > 03 X IS < < < < CO < < Pm o CO Mt CM m Mt Mt m 00 co 00 1— 1 Mt X rH X X rH Mt X rH X CO X CM r^ ON rH oo Mt ON M3 rH Mt O r-H Mt X rH CM r-H X rH X CO MO X Mt CO O < M3 rH CM Mt o m « — 1 3 Mt CM rH in CM rH M3 rH in CM Mt in CO Mt CO 03 c X Ml" O o CO CM m (J\ r^- ONO 4-1 Mt" rH • • • # PQ X • • rH Ml" ON 4-1 •— H M3 CM b£ rH in X r-H X rH •rl Mt co 6C Ml" 0) X •rl !2 03 Sp 4J 0) r* 4J V •5C X • • • 03 • • • )-i • • • • X MO M0 X X ^0 M0 crt M0 M0 X X rH rH rH P4 rH rH rH rH rH rH r— 1 Crt X O o 4J I- 1 1 r-H c c X £ •r-1 o •iM u •rl 1 ctf rH cd £ 00 r-H (30 X 00 o X X • • • MO x MO C -d rH o £ X rH X c T3 rH T3 •r-1 03 •H •rl 03 o •r-1 Q) O 03 o 3-i ctf 0) o •r-1 a) o •r-1 bo m o 03 bO X o !-i bO X o Sm rH X i — 1 03 rH 03 >N >N >N >N X X rH 1 - 1 Pi 3-1 rH rH 3-i rH rH 3-i •rl •r-1 03 03 •rl •rl 03 rH •r^ •r-1 03 M ft £ a X 03 OS X r-H £ £ X 03 T3 w X X £ X g -a *rl X 5-i X O • • 03 £ • • 03 03 • • 03 Pi > > 03 •p- 1 > > 03 > > > 03 O < < X X < Si cn CO CM On r-. d 00 -JC m * m 44 cn > . • rH • Si • Si • * o * d o o co on CM 00 r— H ON CM r^. s cn <}■ M3 o M3 CN d CM M3 rH vD Pm 00 M> vO rH OO cn CM CO G\ M3 d e • • • rH o o <3- oo CO CN vO cn CN cti . O o d •H dr-4 LH '1— 1 o 3 % CO d CL, >vO tJ*- H d X < < < H 4-1 o Ci] r^. vO CNJ O •H 04 rH V d 4J 4-1 •P3 o 03 • • 03 Pm CL. d m CM ON <1- O 00 OJ co CM o o CN M3 X e PS CM , — i cn CO CM lO rH NO I-'- 4-1 •H =) CM d O LH Jr Jr i" r •£ Si o 4c 44 > £ 5m • o • -JC LH • • CO • • • • • o • o d d M-l £ £ £ O £ £ PS £ £ cn £ £ £ 6 £ £ cn 4P O 00 cn oo oo Eb 00 d oo oo PS oo oo 00 ob 6b ob H PS Cfl d d d d CD d PS 5 d X 4-1 4-J d d £ 4-1 cn ctf S d CM OS 2 rH CM CO X X • MS d m H Q) d d 4-1 MS d 00 d o d d CO tH £ 6 m •rH 4P o •rH •H 4-1 •H o •H a) CCJ 3 3 L i 4-1 o d d 4-J d rH £ cn cn V d 00 4-1 oo 00 oo 00 (1) d d 23 ■H CO CO £, M-H o o o CM • m • • • vH a o 4J H 4-1 £ £ X) £ £ cn d o W 4J X d oo c ob o d 00 d ob C C X X d -d ■ - 1 4-» 5 O •rH X •H •H •H O •rH •H •H o CO o , — i 4J o d •rH d O O Cv3 o H O •H 03 o cti o 04 o d d d 5m H rH u 00 o •H bZ o d 00 o H oo o bO W) MH rH MH 6 d d d d d rH H 1 — 1 Pm - 1 d rH ctf d o CM - o MH -H Pm ?o d > Pm Sn rH rH . — 1 £ 1 - 1 LH •H d O 4J -H jm PM i— 1 Sm H rH M i — 1 H d d d ctf M-H •H cn •rH 5m •H d •rH d d •H d rH •rH d u 4-) 4-1 -P •H 4-1 • jm d d d a. H CM ms ctf CL. ’ — 1 cu o O o O d cn d d -H 4-1 X d TJ CO X5 d X) 4J 4J 4-1 4-J 00 d 5m • M3 1M x S X) •H x> H X •rH d o £ • d • o O • o d • o d • o o e o • CO d M3 d > 4-1 > o H > o •rH > o > > o > > > > S rH PS z < CO < Cm o < Cm Eh X) co 00 pH m cm •CJ o <}• X CM X X Ml* pP <3 ON CO r-- o • • \ — i o CO o X (Ti X 5''~ CM o oo 00 r—H CO X oo 00 V CP CM 1 — 1 o 1 — 1 00 P O d X) •P X) P CM p ‘d <3, CM % CM 1m 4-1 O CO r^. o /A O CO d J-4 • CJ • cu o • d CD o MD /— s Ml* 00 oo 00 CM o CU CO CO X X o Qp CO r* 60 •rH o o o • CP • • CO • • • • • • • • •rH CO CD o . 6 b E O B B JS B B co B B e B £ & CO oo CO 00 oo bO S cu S 00 qs X X b0 X bD 60 f* CD V— *p JS co -l cp X r-H CD CU CU • 4-1 lu d 00 d o d d CO i — 1 6 £ •^o •rH 4-1 rn o •rH *p p *p o •p QJ d d d U0 £ UJ p d o d d 4J d i — l £ CO C0 \/ H 00 p 00 X X X cti CD d d £ c 1 X CO e MH o o p-i o •I— 1 • X • • w' ■ o o J-4 CM o £ B X B S. 4-1 4-1 CO u X d & d S o d S X) d s d d X X /T— N d 4P o 1 P £ o •rH X •p •rH •rH o •rH •rH •rH o o CO O r— 1 d •p d o o d o p d o •rH o d d o /-"N o > cu km r—H r-H r-H r-H 1 — 1 £ o d Op o 4-> 1 — > p PM (P p P i — 1 P i — 1 p d d d d d CD •rH •rH •rH p •rH cu *P cu CU •rH CU rp •rH cu 4J 4-> u £ p MH MH co • p d cu d cm P d CM X CM tP ctf CM o o o o •rH CO 4-1 S CU •rH p Xl CU X CO XJ d XJ 4J 4-J 4-1 p d d d X p X) S X •rH X p X 60 d o 6 • d • o o ■ o d o o cu • o • • • • •rH CD 00 • d > p > o p > o •rH > o > > o > > > > CO S os Z < X <3 Cp o < Cp Cp < Cp o < fp < < <3 < * i — i CM 41 B . Carcass Characteristics The criteria for carcass quality evaluation are presented in Table 9. Although no statistically significant ration effects resulted from these trials, some trends are worthy of comment. Animals on the 50 and 1007, R.O.M. rations had longer carcasses. This could probably be expected as the animals were older at market weight. Hussar and Bowland (1959) fed R.O.M. as 107, of the total ration and reported that pigs tended to have shorter carcasses than control animals. Similar results were reported with thiouracil feeding (Bowland 3 1957). No explanation of this apparent contradiction can be offered. Pigs on the 50 and 100% levels of R.O.M. had a decreased area of loin. This confirms a similar report by Hussar and Bowland (1959) . Backfat measurements were essentially unchanged by R.O.M. feed¬ ing. Group- fed animals had 1.42 as compared to 1.32 inches of backfat for individually- fed animals. Zessin et al. (1961) and others have reported a similar backfat reduction when feed intake was restricted. The levels of R.O.M. used did not influence dressing percentage. Pigs on the 50 and 100% R.O.M. rations had higher R.O.P. scores and super¬ ior carcass grades to the 0 and 25% R.O.M. groups. Gilts showed overall superiority in carcass quality as compared to barrows but there was no ration x sex interaction in carcass character¬ istics. Bennett and Coles (1946), Charette (1961) and others have reported similar differences between gilts and barrows on non-goitrogenic rations. In general one might conclude that the levels of R.O.M. used in this study have had no marked effect on carcass quality. Any possible advant¬ ages derived at the 1007, level of R.O.M. feeding would certainly be offset by decreased rate of gain and reduced efficiency of feed utilization. . : . 1 . .... ... Ml r^. M0 cn i— 1 • o • •rJ o ON rH pH o CM m CO pH C/3 00 in s pH o in O • • • n CM i-m 00 pH oo CM to d m • • • cu o CM 00 ON ON i — i pH Pm to in m 1 *H : — i CM > d -h O TO mi d O H MM 4-1 CM o O O • • • o oo ON o pH pH CO m 00 cn o i — i •rH -U CO •pH • • • h cn •pH cd C/3 cn Ml cu > PS IS < Q X d • • cn CM m i — 1 ON pH -X m CJ d JO „ Ml • • CU d 5^ d TO •pH •rH r— 1 d • o u4 JO CO pH cn CO • in 60 #N in •H m tn iu d Cu V » m d a •H d Ml CM JO •H d Ml cd a) • 60 o • d •H > o • > M CO < < o ex < -X pH of 10 boars . " : , / . K- : ! O’ ' • l-l • . i ■ : ! < • a 0 : l . > - « !~ T • • • • 43 C. Reproduction Table 10 outlines the data from the reproduction studies with pigs and rats. These results show considerable variation both within and between groups. While such variation is normal in reproduction studies it creates problems of interpretation. This consideration, coupled with limited numbers of animals, prompted the author to dis¬ pense with any statistical analysis of the data. Only 15 of the original 20 gilts farrowed. One gilt was lost from each of lots 2 , 3 and 4 because these animals did not conceive in the prescribed 4 oestrus periods. One gilt in lot 3 was injured at the time of breeding and the other gilt from lot 4 had not conceived when she died of infectious nephritis 112 days after reaching 210 lb. in weight. The results are confounded by the fact that 5 littermate gilts, 1 in each group, were either late in reaching puberty or were much more severely affected by R.O.M. than other gilts. Two of these animals (lots 2 and 3) were marketed because they did not become pregnant; the third (lot 4) died of infectious nephritis. The gilts from this litter in lots 1 and 5 conceived normally on the first breeding period. The most striking effect of the 50 and 100% levels of R.O.M. was the delay in onset of puberty. All gilts that farrowed on the 0 and 257o levels of R.O.M. conceived on first service after they reached the required breeding age; oestrus periods had been noted in these groups previous to this time. Gilts on the 50 and 100% levels of R.O.M. did not conceive until an average of 62 days after reaching 210 lb. while the basal and 25% R.O.M. groups were pregnant 21 days earlier. Kennedy 44 and Purves (1941) noted a delay in development of the ovaries of immature rats fed rapeseed. Gilts on the high R.O.M. diets may have experienced a delay in onset of puberty because of a delay in ovarian development as Kennedy and Purves suggested. Boars in all 5 lots had reached sexual maturity at the age of 240 days and breeding performance, as judged by their ability to sire litters, seemed completely normal in every instance. Bezeau e_t al. (1960) reported that ewes fed R.O.M. as 30% of the total ration lost weight during the gestation period. The maximum level of R.O.M. in the reproduction period in the current study was 127, of the total ration and gestation gains were normal. Lucas et al. (1958) noted that thiouracil- f ed pigs had longer than normal gestation periods; gilts in these experiments were not similarly affected as length of the gestation period was uniform at 112 to 114 days. Number of young born alive per sow and birth weights were normal in all groups. The weight of the piglets at 5 weeks of age was reduced from 16.6 lb. per animal in the basal group to 13.1 lb. in the 1007, R.O.M. groups. Presumably this could be a result of lactation inadequ¬ acy such as Bell (1957) has reported with mice. Rats used in the reproduction study all seemed normal in so far as age of sexual maturity and cnnception rate were concerned. Maqsood (1952) reported that Rowlands observed that male rats rendered hypothy¬ roid by thyroidectomy did not experience normal testicular maturation. Krohn and White (1950) and Jones e_t al. (1946) have reported normal conception rate in thyroidectomized and thiouracil treated rats but both noted that fewer young were brought to term due to foetal resorption. . - . ... _ • - . . .. . . ; .. : i - - ...] i‘l : .. - . . i -■ - t j „ j . i o v i .i . . .. : ■ : (; 45 The number of rats born per litter was reduced from 11.8 at the 0 level of R.O.M. to 9.0 at the 1007. level of R.O.M. feeding. The main differ¬ ence, however, was that females on the 1007. R.O.M. averaged only 6.5 living young at birth as compared to 11.8 for the basal group. It is of interest to note that 2 of the 4 females on the 1007. R.O.M. + lysine diet completely resorbed their litters. Jones et al. (1946) has repor¬ ted 1007. resorption of litters in rats when thiouracil was fed for over 100 days. If this phenomenon is due entirely to a thyroid condition then one wonders why some resorption did not occur in group 4 which should have been equally affected to group 5. Average birth weights of rats were quite normal in all ration groups but since serious lactation difficulties arose in many animals regardless of ration no further litter data are available. Only 4 of the 18 litters were weaned, 1 each in groups 1 and 2 and 2 litters in group 3. Post mortems on several females revealed little or no active mamm¬ ary tissue, the reason for this lactational disturbance is not known but it certainly could not be attributed entirely to R.O.M. as females on the basal diet were similarly affected. Histological sections of male and female gonads at 12 weeks of age revealed no distinct abnormalities in any of the rats. Levels of R.O.M. up to 67, of the total diet (lot 3) can be used in rat and swine diets with no consistent deleterious effects. The 127, level (lots 4 and 5) promoted foetal resorption and stillbirths in rats. Lactation results were not encouraging with either species. 46 Table 10. Reproductive Performance of Pigs in Experiment 356 and of Rats in Experiment 1A Pj-Ss R.O.M. % 0 25 50 100 100 + L Sows farrowing per lot 4 3 2 2 4 Days from 210 lb. to breeding 39 43 68 54 63 Sow wt. at breeding lb. 257 258 264 266 274 Total gain gestation period lb. 131 142 140 134 121 No. born alive per litter 9.0 8.7 9.5 8.0 9.0 No. weaned per litter 7.5 7.3 9.0 5.0 6.8 Av. birth wt. per pig lb. 2.6 2.1 2.7 2.1 2.4 Av. wt. per pig (5 weeks of age) lb. 16.6 15.5 15.4 12.6 13.5 Loss in wt. of sow (farrowing to weaning) lb. 63 65 89 60 52 Length of gestation period 113 114 113 112 113 Rats 1 No. of litters per lot 4 4 4 4 2 Number born per litter 11.8 12.2 11.5 9.0 9.0 Number born alive per litter 11.8 11.5 10.3 6.3 7.0 Av. birth wt. gm. 5.9 6.0 6.4 5.7 6.1 ^Two resorptions from lot 5. Averages do not include these 2 females ■ • • . ' . : • - . • » • 47 D . Digestibility and Retention Experiments (a) Swine Studies In order to simplify comparisons between pig and rat digestibility data, the results for apparent digestibility of nitrogen, energy and dry matter-*- are given as digestion coefficients. Digestibility figures are based on 107, moisture in both feeds and feces since it was found that random samples of feed and feces showed dry matter contents of 90 + 17.. The data from the swine trials (Table 11) show considerable variability. In general lot 4 animals receiving 1007. R.O.M. exhibited the lowest digestibility coefficients of any group. Lot 5 animals, receiving 1007. R.O.M. plus lysine, were higher than lot 4 except in the finisher period. This increase reached statistical significance (P< 57.) for A.D.E. and D.M. digestibility in the grower period and for A.D.N. in the reproduction period. A.D.N., A.D.E. and D.M. digestibility tended to decrease from lot 1 to lot 4. Ration 3 (507. R.O.M.) pigs did not follow any particu¬ lar trend and it seems reasonable to conclude that the 507. level of R.O.M. supplementation did not, on the average, affect digestibility coefficients. Hussar and Bowland (1959) got more consistent results in their work and reported decreased energy and dry matter digestibility at a 107. level of R.O.M. supplementation. It will be recalled from the previous discussion of rate of gain and efficiency of feed utilization (Section A, Tables 5 and 7) that during the grower and particularly the finisher periods, pigs on the high R.O.M. diets became more tolerant of the R.O.M. goitrogen. This could explain why A.D.N. , A.D.E. and D.M. digestibility coefficients obtained lA.D.E. , A.D.N. and D.M. digestibility refer to apparent digestibility of energy, nitrogen and dry matter. - . . ; ... ; : > . . ; . - . - • j . . : _.... . ' ,.[ . • . .. .. . s'Jt: .! . - . .. . b o j s . ; j ' : . . . j. I <. 48 from pigs which had been on experiment for at least 75 days did not show marked effects of the R.O.M. rations. Possibly if a digestibility study had been conducted 20 to 30 days after the initiation of the experiment when the animals weighed 30 to 40 pounds and were experienc¬ ing the most serious growth depression on the high R.O.M. diets, the digestibility results would have been more conclusive. In the finisher period boars showed significantly higher energy and dry matter digestibility than was shown by gilts. Since there was no sex x ration interaction this sex difference is not attributable to R.O.M. During the gestation period there was a significant increase of A.D.N. from 757> in lots 1, 2 and 4 to 817> in lots 3 and 5. This effect was particularly evident with the 1007> R.O.M. + lysine group which was 67. above the unsupplemented 1007o R.O.M. group. Similar, though non- sig¬ nificant, trends were present with A.D.E. and D.M. digestibility in the gestation period. No significant digestibility differences were present in the lactation period although lot 4 animals consistently had lower digestibility coefficients than other groups. The lysine supplemented lot had A.D.N. , A.D.E. and D.M. digestibility coefficients 6 to 107o higher than lot 4 animals during gestation and lactation. In view of results obtained with rats, to be reported later, it seems unlikely that the additional lysine was entirely responsible for this noticeable in¬ crease in digestibility although since the trend occurred in the grower, gestation and lactation periods one cannot preclude the possibility that improved protein quality was involved. Further experimentation is required to clarify this point. . ^ : . ... L XL _ .Zn X . ..Z' Z ... - ' • , . rt 01 . ... ; i ~ ■, . ;. . . : . . . . . . .. - - j ; :. o3i X s:. . 49 (b) Rat Studies The results of the rat digestibility and retention studies are presented in Table 12. The digestibility trial with rats was conducted in the second week of the starter period; in this way 1 week was allowed for ration acclimatization. Contrary to the data from the pig digesti¬ bility studies the results were uniform and more amenable to satisfact¬ ory interpretation. Rats on the 0 and 257<> R.O.M. diets had higher A.D.N. than rats on the 1007<> R.O.M. diets. The 507> level of R.O.M. consistently produced intermediate values. At the 0 and 257. level of R.O.M. , A.D.N. was only 3.37, greater than the 1007. levels. However, a similar comparison of percent A.D.N. retained shows that at the 1007. R.O.M. levels 9.57 , less A.D.N. was actually utilized as tissue protein. Hussar and Bowland (1959) reported that R.O.M. as 107. of the total ration did not affect the retention of nitrogen although they noted a reduction in A.D.N. at this level of R.O.M. feeding. These results suggest that besides being less readily digested by the animals, the protein of R.O.M. was not used as efficiently as the protein of soybean oil meal. Presumably this diff¬ erence could be associated with the inferior protein quality of R.O.M. or more probably to a combination of inferior protein quality and an overall metabolic disturbance arising from thyroid gland malfunction. Thyroxine at normal physiological levels stimulates protein anabolism (Pitt-Rivers and Tata, 1959) and hyperthyroidism increases protein catabolism. Konigsberg (1958) treated developing chicks embryos with thiourea and got inhibition of growth of skeletal muscle cells by _ j - - - - . - \. - - .. i i-- .. . ■ ~ — cr-- 1 o l. f <•-. . . a ..... .. -■ -L . • • J. -• . - - - - O - - ■ J. C . ...... . - - - J ' - . - . _ . J - 50 reduced protein accumulation in the cells. Normal protein levels could be restored by thyroxine injection. He concluded that the protein synthesizing mechanism was interfered with when thyroxine was not adequate possibly because of disruption of normal energy pathways. Such an effect could be associated with the decreased nitrogen retention in the present study. The growth data discussed previously and the digestibility data of this section imply that additional lysine was of no benefit to the rat and that protein quality in so far as lysine is concerned was not limiting. Apparent digestibility figures for energy and dry matter decreased as the levels of R.O.M. increased. The 50% level of R.O.M. supplementa¬ tion resulted in a non- significant decrease of 1%, while at the 100%. level significant reductions of 4%, occurred in energy and dry matter digestibility. There were no differences between males and females in digesti¬ bility of A.D.N. , A.D.E. and D.M. although there was a tendency for females to retain less of the nitrogen digested. The data from the digestibility study done on approximately the 18th day of pregnancy followed a pattern very similar to the one previ¬ ously described. A.D.N. , A.D.E. and D.M. digestibilities all decreased with the higher levels of R.O.M. A similar trend was evident with retention of gross nitrogen. An overall summary of the data indicates that as the level of R.O.M. in the diets increased apparent digestibility of nitrogen, energy Nitrogen, Energy and Dry Matter Digestibility Individually-Fed Pigs, Experiment 356-*- 51 I I CO * u co co m o oo vO oo X r—i o • • • • • • • • •H o 00 O CM CO X vD X o r— 1 vO X vO X r^ vO X (/) Cl as oo ON UO ON X d • • o • • • • • • o X ON » co oo X • • • 9 • • • • • • • • o co CO vt 00 CF\ CO CM X C7N r— 1 X o r-. vO X vO 00 X r- f— 1 O B C PQ Csl i — 1 /— N CO 00 X LO O oo o • • • • o o 1 P3 X d o O X 00 X CO CTi i — i X OO X • • • • 0 • • • • • • • CM co oo o CM X oo o X r— 1 X vO X X x r^. r-'. X X X X X X \D X w Cl d X o O x < X X o X o X o o X 00 r-'- • • • • • • •» • • • • • o O CO in 00 T— 1 X ON 1 — 1 d vO v£> 00 o X vO vO r*. i — r^ o v£> X X r— •H X d X w cu X d * *3$ .V o vO b^ B'S 8*2 &-S xO CT'* •sJJ O'"* d •Co xP «r'- vO •rH X X *>J0 •sJ3 b^- s-5 d X X X o o d O'! X w X X o X X ■ — 1 X X •H •rH *x •rH •pH r— H T) r— 1 60 1 — 1 d r— 1 CO •rH O •rH s_/ •rH X CO •rH 60 X •H X X 00 X ■H o •H Cl •rH d •pH X •pH •pH cu •H ■U (U 4J o -U Cfl a 4-J Ci CO a CO •r4 CO Ci CO X a) cu Q) X CU •X X CU O a 00 Cl 00 o 00 X o 00 •pH a) •rH 3 •pH 1 •pH . M Cl o • "O X • • n0 X • • XJ > • • a CU 0) cn z w o w X 3 XI £ • • •H • • • Cl • • • d X • • • o E o p Q S d Q p a cu Q a a cu E P P a 3 Cc • • • •pH O • • a) • o • 5 3 • • • OS Z o C < Q Ph < • • o • 0 • • * • . . . £< 52 4-1 •H r— I W 3 t-H 3 E 3 t, cn ■-i 4-J d • o • o • o o • • • • O CM W QJ o MO M3 m m ON CO v£> m M3 o M3 ON 00 03 CM « — i QJ s m r-H M3 r-'. m CO 00 m 00 00 00 CM in r-H lD 00 -pH CM o cn 00 CD •pH )-l CM • — i a qj CL. Ctf PH X H QJ td 4-4 < 00 m O 00 CM r-*. CO lD MD V Sn CM m 00 PQ u CM Q 4-4 CCS "3 d PQ PQ 4-1 CCS < C < < 7* r jf r* oo • • • • • 4< £ ir T> jf > d 3 o Ph gm gm gm gm mg tr** •3J5 v- 0 b"- 0 •pH b^ b^ -nJ5 b^ pd 4-1 4-1 4-4 •rH d 3 Md •z •pH 4-4 • 4-1 d 3 cn 6*5 •rH •pH 00 3 m 5 CCS 0 OO •p 00 0 • >3 V 5 si r-H E 4-4 M-H 4J Pl4 0 00 QJ o ■3 00 •H O "3 •rH pH •H £ £ 1 — 1 r-H 3 r-H ■U cn QJ 3 d oo d - cn d •H Cd si 4-1 5 cn -pH •pH C O 0 so 3 4-1 •pH Si a oS d ccs o -a 3 •H V ■3 r— H •rH "3 3 3 •rH -U 3 PH i-H o oo o QJ 4-1 C^J O 4J PH 4-1 4—1 d 3 Cti o . — 4 4-1 3 4-J CD O P4 CO si 3 CO cd <4-H •H >3 cn pH > > o o Ph • • •rH 0 • •rH 3 • Ph • CO £ os Z < < < PQ IS < O < < Q z Q w Z < O < Q r— H •pH CQ ctf o •pH M-l •pH d 00 •rH cn >3 ph 3 > o d "3 •rH X) 4-) cu •rH P4 o co PH 3 a, 3 cn E CCS cn . 7l ■ • • • • » * 53 and dry matter decreased although this effect was significant only in the rat experiments. Supplemental lysine in rations containing high levels of R.O.M. may have increased swine digestibility coeffi¬ cients for nitrogen, energy and dry matter but it was ineffective for rats . E . Blood Serum Protein-Bound Iodine Rat blood serum P.B.I. values were determined at 5 and 12 weeks of age. The data are reported in Table 13. There was some difficulty in obtaining enough serum from the 5-weeks-old rats. Making a pooled serum sample from 2 or more rats on the same treatment might be con¬ sidered as a way of alleviating this problem in the future. The P.B.I. values for the five 12-week-old male rats in lot H were not included in the averages in Table 13 since these determinations were all extremely high. Presumably the samples had been contaminated either from the atmosphere or the reagents. P.B.I. levels fluctuated considerably with¬ in, as well as between, groups. R.O.M. did not have any definite effect on P.B.I. values with rats at either 5 or 12 weeks of age. Swine blood serum P.B.I. values from the group-fed pigs were reduced from 5.32 in the basal lot to 3.13 and 3.56 ug at the 50 and 1007, levels of R.O.M. feeding (Table 15) respectively. As will be dis¬ cussed in a subsequent section swine thyroid glands showed moderate hypertrophy as the levels of R.O.M. increased. The coefficient of correlation between P.B.I. and thyroid gland weight was -.538 (38D.F. P <1%). P.B.I. values of the magnitude obtained are well within the nor¬ mal range for humans of 3.4 to 8.0 ug per 100 ml. of serum cited by . . . - ... . : . ; . .. . .: .. ■ . d.: d ' . : d ;. - .• . . ... : d>- - - - : - r.U . .. .. .... - . ... . d .. ... ' *•_ :.::j . . .jj...: .. „ . ; . d i r :. . . ... .. . - . I - ... - .. : - . .. .... . .; i ..:... . . . ' . ..... .; . .'. l , J. — . . d .. 54 Barker (1951). Gawienskie £t al. (1955) determined P.B.I. values for swine, presumably normal, and found a range of 1.2 to 5.4 ug per 100 ml. of serum. This means that the P.B.I. values in the current study obtain¬ ed from animals fed R.O.M. diets, while unquestionably reduced, may still be normal. The growth and food efficiency data from the finisher period indicate that the animals were not experiencing any particular stress from the 50 and 1007, diets. In view of the above observations coupled with conflicting reports in the literature as to the validity of P.B.I. as an indication of thyroidal activity, one hesitates to state unequivoc¬ ally that a decrease from 5.32 to 3.13 ug iodine per 100 ml. of serum represents a definite deficiency of thyroid hormone secretion. It seems certain, however, that the animals in the 50 and 1007, R.O.M. groups showed hypothyroid tendencies. F. Thyroid Gland Morphology Group- fed pigs in Experiment 356A did not show marked glandular hypertrophy, although animals on the 50 and 1007. R.O.M. diets had thy¬ roid glands 257, heavier than control animals. Histological sections of these glands did not indicate marked hyperplasia or increased cellular components. Hussar and Bowland (1959) found definite evidence of thyroid hypertrophy and hyperplasia when Argentine- type , expeller-extrac- ted R.O.M. made up 107, of the total ration. In the current study the finisher ration contained 9.67, solvent-extracted Polish- type R.O.M. The results suggest that this meal may have been less goitrogenic than the one used by Hussar and Bowland. This could be related to type of meal or method of processing. .. - v - - . — . . ; ... ; .. 0X3 ; .£ i Ji :.-L - : .... I . - . . - J - - .. . . .. - . £ ••• • - •• ; 1. - . ■ _ . . .. : - j - ... - ■■ . - 1 : i . . -■ ■ . .. . . . . . . . .. - - .1- „ .: . . : .... : ... ... . . : - XJ - . v. - • - . . ' - . . .. 55 Van Middlesworth (1959) reported that propyl thiouracil fed rats could be injected with sodium- 1- thyroxine daily until P.B.I. values were 2 to 3 times normal. These animals still showed signs of goitre despite the above normal blood thyroxine level. This phenome¬ non was attributed to an increased sensitivity of the thyroid gland to pituitary thyrotropin. If other goitrogens (viz. thiooxazolidone) could act similarly, then thyroid gland hypertrophy, unless very drastic should not be considered irrefutable evidence of thyroid malfunction. Thyroids from rats fed R.O.M. in Experiment IB showed definite hypertrophy as gland weights increased with increasing levels of R.O.M. By the end of the second week on trial a moderate degree of hypertrophy had begun; rats on the 50 and 1007, R.O.M. diets had glands 407. heavier than those on the 0 and 25% R.O.M. groups. After 3 weeks of feeding, hypertrophy was more marked as evidenced by an 807. increase in weight. Thyroid gland weights from animals fed the R.O.M. diets for 9 weeks were still 35% heavier than the 0 and 257, R.O.M. groups. These results are illustrated by Table 14 and Figures 4, 5 and 6. It has been noted previously that thyroid glands from pigs at market weight on the high R.O.M. rations were only 257 > heavier than the basal lot and on histological examination did not show abnormalities. Thyroid studies of rats on trial for 9 weeks tend to confirm these findings. Pipes et a_l. (1958) and Hussar and Bowland (1959) have re¬ ported that a time lapse is necessary for the goitrogen to exert its maximum effect. The present study indicates that with rats this maxi¬ mum effect comes at about 2 to 4 weeks after the initiation of feeding . s.-C . . .. . - -- - - . 56 R.O.M. Following this time the animals apparently adapted themselves to the goitrogenic diets as is demonstrated by the decreased thyroid hypertrophy and increased body weight gains in the finisher period in comparison to control rats. G . Standard Metabolic Rates Basal metabolic rate determinations have been widely used as an indication of thyroidal activity and despite their non-specific nature they must be regarded as one of the most useful techniques for the estimation of levels of thyroid secretion (Pitt-Rivers and Tata, 1959). Thyroxine administration has been demonstrated to accelerate oxygen consumption by most body tissues both iui vivo and in vitro (Barker and Klitgaard, 1952; Reid and Kossa, 1955; Boyd and Oliver, 1960). Elevated basal metabolic rates are accepted as being indicative of a hyper thyroid state and Pitt-Rivers and Tata (1959) have theorized that this may be the result of uncoupling of oxidative phosphorylation. This would result in inefficient energy trapping as high energy phosphate bonds by hyperthyroid animals. One would expect the converse effect in a hypothyroid state such as the R.O.M. goitrogen might induce or, if the R.O.M. isothiocyanates acted directly at the tissue level as Bach and Benda (cited by Bell, 1955) have reported. Since it was considered unrealistic to use the term basal metabolic rate with rats (as opposed to humans) the conditions were kept as standard as possible and the term standard metabolic rate has been employed (see page 26 for a definition of this term) . As the levels of R.O.M. in the diet increased the standard metabolic rate decreased; this tendency was statistically significant (P<1%) in Experiment 1A and a similar trend was evident in Experiment IB . — , . . ‘ . \ jo/: :if , - ■ .. . ... . 1 . . . 57 Figure 4 Rat Experiment IB Thyroid Photomicrographs, 2 Weeks on Irial 25% R.O.M. (Rat 2 C, Male). Thyroid weight 12.5 mg./lOO gm. body weight. Normal, actively secreting gland. 100% R.O.M. + Lysine (Rat 5 C, Female). Thyroid weight 17.8 mg./100 gm. body weight. Glandular hypertrophy and hyperplasia are evident Magnification = 184 X 58 figure 5 Rat Experiment 1 B Thyroid Photomicrographs, 3 Weeks on Trial 0% R.O.M. (Rat 1 D, Male). Thyroid weight 7.4 mg./lOO gm. body weight. Normal, actively secreting gland. 100% R.O.M. + Lysine (Rat 5 D, Male). rh\ roid weight 15.2 mg./lOO gm. body weight. Glandular hypertrophy and extreme hyperplasia Most follicles devoid of colloid. Magnification = 184 X .•*V . .A - 59 Figure 6 Rat Experiment 1 B Thyroid Photomicrographs, 9 Weeks on Trial. 25% R.O.M. (Rat 2 A, Female). Thyroid weight 12.3 mg./lOO gm. body weight. Normal, actively secreting gland. 100% R.O.M. + Lysine (Rat 5 A, Male). Thyroid weight 8.3 mg./lOO gm. body weight. Follicles well filled with colloid indicating normal activity. Gland shows no hypertrophy although it may be slightly hyperplastic. Magnification = 184 X 60 Rats on the 1007o level of R.O.M. showed the most uniform decrease in oxygen consumption while animals on the 50% level were quite variable although the average value shown in Table 13 indicates a general reduc¬ tion similar to the lot 4 and 5 animals. This variability in performance at the 507, level of R.O.M. supplementation has been noted previously and is ascribed to the greater ability of some individuals to tolerate the goitrogen. Correlations of -.385 and -.121 were found between thyroid weight (mg. per 100 gm. body weight) and standard metabolic rate at 17 to 20 days and 24 to 27 days on trial respectively in Experiment IB. The required coefficient of correlation to reach statistical significance with 8 degrees of freedom at the 5% level is - .632. Therefore the degree of correlation is rather low and one must conclude that if rate of oxygen consumption can be regarded as being indicative of levels of hormonal secretion as suggested by Pitt-Rivers and Tata (1959) then thyroidal hypertrophy should be considered supplementary rather than concrete evidence of thyroid gland malfunction. H . Liver and Adrenal Weights Liver and adrenal weights showed no significant ration effects with the varying levels of R.O.M. in the rat experiments (Tables 13 and 14). Bell (1955) reported evidence of liver enlargement in R.O.M. fed animals and Money (1955) and Nichols and Rossiter (1955) noted decreased adrenal weights with rats in a hypothyroid condition. Brown-Grant (1958) reported that thyroidectomy and methyl thiouracil treated rabbits showed no definite adrenal changes although he considered it conceivable that hypothyroid animals might secrete less adrenocorticotropic hormone than normal . .... . I • . . ' 61 Female adrenals, but not livers, were heavier than male glands after 9 weeks on trial. After reproduction females had heavier livers as well as heavier adrenals than males. Once again no ration effect was evident and presumably this is nothing more than a normal reaction to the extra stresses imposed during gestation and lactation. The market pigs showed a definite but statistically nonsignificant trend to heavier livers with the increased levels of R.O.M. Barber ejt al . (1960) found that supplemental copper decreased liver weights as compared to control animals that had sub-optimal levels of dietary copper. This work suggests, as the current study does, that nutritional stresses often cause increased demands on the liver and as a result this organ undergoes variable degrees of compensatory hypertrophy depending on the gravity of the situation. Therefore it seems that even though the extent of liver enlargement with the group-fed pigs was moderate, one should not preclude the possibility that the liver and/or other organs were not functioning normally. Histological sections of adrenal glands from both species did not exhibit abnormalities and photomicrographs have not been included in the manuscript. t v '■ L « • 1 . . • ... - ■■■■■■- J Glandular Weights, Blood Serum Protein-Bound Iodine and Standard Metabolic Rates Rat Experiment lA^- - 62 - (/) * > <- 4) NO -5c > * r-H cn ON o CO 2 m 00 CNJ 4) o nD o O rH &H r-H r-H CNj t—H W r-H 4) NO CNJ ON r— 1 oo - T3 " o O >N C o 43 "O cd 43 XJ O /N o • 40 00 • cd i- H 00 . cu g g cd g 0-) I— 1 o 00 2 o oo • \ — i Cd cd o /— s r-H CU o /^N cd •i— i r— 1 • o • 4-0 r— H • o • un •rJ 54 \ 0J o 4J mh 4-J o 4J V 54 o 0_) • 3 r-H £ o CN • 2 r4 2 J-) •r-i oo \ c 00 i — 1 C g • • o g . c O O £ > •r4 N-^ g 4-1 o JO bO cd OJ 00 cd CO CXJ CO 0-1 O CO 0-J N — ' CO 0-1 CN 0-J 4* 43 P 0-J 43 -U 4s! dS • CU a) 00 -U • -a cd 00 0-J C cu !-o M g a) •H t— M o 54 •rH 43 cd CU 4) b0 • 5-i o a> 4H CN P-i 54 r-H £ CM 5-i i — 1 3 •rH • 54 cd 4-0 cd 54 cd c s 54 a) g T3 O c u g 5-J CU C 54 bO • cu .n P c u 0-1 g 54 > CO • 44 P a) o-i d T) •rH (U 44 P XJ •iH cd < Z CO CO Cd < iJ CO c Z m in vO o pH H pH rH cn CO o d) pH G\ 1 — 1 o CO CO X rj m CO CM 00 r— 1 r— 1 Jh as X X X vO CM pq o + PQ CM CM <2 m CO X X o • • • • • o o CN vD ON cd f 1 p H rH a) 6 o Sh pg pH vO 4h o 00 < o r— 1 «n CO >•> o • • • • • r-H f— 1 CN CTv pH V X o i — 1 pH X C PQ vO CO PQ m v£> o> CN 4-1 X cn • • • • • cd •pH CN r— 1 00 00 X r— 1 4-J c X cd a o •pH •pH Sh in pH 4H CJ PQ o in X •pH cn o •vt G Sh o • • • • • 00 CU CN pH o r'- •pH CL pH 1 1 — 1 CO 3 cn r* aj \r r- a • i- i- cd 4-J _v n i— 1 cn o c— 1 pH cd pH cd cd •tH 0) •rH •H Sh X u u !h X X (D 4-J X / — V Oh • • CD a) C • • X C -u G x X X O x X (U o 2 O 3 cd cd 3 m •pH pH 5h /*N !h cn V 3 cd CO pO cn >> pH rH X £ a >. X O cd O cd 0) X PM 3 as cd o cd o •rH •pH •H •H > — I — I H < in X cO m r— 1 c cn CD cd 4-1 p-H d -Q CD CD cd > B H •pH •r— 1 hJ 5-1 C/ CO CN] 4- • • r— 00 o oo •r~ m CN] e cO r— 4 m 3 CO oo c • 5- oo CN] co 5- in CO cd m pa r-H hJ + O o o o o m CD • ** O i CD X c w •H X o M X d p o CQ l d •1—1 CD 4-J o }-l Pl, B P u a) co X o o r-H ca m CN * oo oo 00 oo 00 o o < 04 04 cn CT> o CQ cn CO 4-1 J/ f* • 00 jP f* r— 1 4-1 00 • B CL JP •pH M 00 CD • o S'? 14-4 •r-l 3 PQ o O CD • r-H 3 X P* • 5-4 •pH • S CD 5-4 o £ 00 • JP CD 5-4 d p O 6 > u • P •rH jp CD oz S H H CO cfl d cd o •i— I c 00 •H CO CD X JP u cd CD B o u 5-i PQ 4-1 pg AB V 4J < vD p^ O m d • • u |\ 00 cd XJ «n CNJ •pH m -U XJ r— H d cd -U o a •pH •pH < mh u PQ CN •pH o in co d CO • • 00 vO m m •pH - j. . r : vV , ‘ j- . : : . ... ■ ..... j . . . . . . . . ........ ..... . . ... : . . o.' . . . . . . ...... .... . . . . . . . _ . ...... . ....... . . . . . . . . .... . C. . i i' ...... . J J. . . . . ... L . .. . 66 slightly by the high levels of R.O.M.; carcasses tended to be longer and have less backfat although they had smaller loin areas. Rats responded similarly to pigs, although differences in rate of gain and efficiency of food utilization were much more definite with the former species . Reproductive performance was adversely influenced by the 50 and 100% levels of R.O.M. The effects manifested were delayed onset of puberty in pigs; reduction in number of young born alive in rats and a general lactation disturbance in both species. Energy, nitrogen and dry matter digestibility coefficients were lowered for both species as the levels of R.O.M. increased, but the differences were significant only for rats. Nitrogen retention by rats was lowered by the 50 and 100% R.O.M. diets. Pigs receiving 100% R.O.M. plus supplemental lysine had digestibility coefficients higher than the unsupplemented 100%, R.O.M. diet. Additional lysine was ineffective for rats . Standard metabolic rate determinations done during the third week of the experimental period showed a reduction of oxygen consumption by rats on the high R.O.M. diets. Blood serum protein-bound iodine values for rats were within the normal range and were not influenced by R.O.M. levels. A significant reduction in P.B.I. of swine serum was noted when pigs received 50 or 100%, R.O.M. Serum P.B.I. values were negatively correlated with increased thyroid gland weight and these results provide evidence of a thyroid disturbance. Swine thyroid histological studies showed no definite trends. Rat thyroid glands were enlarged and hyper¬ plastic after 2 to 4 weeks of R.O.M. feeding although after 9 weeks on trial this tendency had been overcome and glandular activity seemed — .... ...... . . ......... . . : . . t . ■ ■ . . . . ... . ... ... . . . . : ...... o j ./ . . .......... . - . ' - 1 . .. . , . ... ..... . : . . ... ... . . . . ; i . ... ..... , ... * 0--... . ’ . • .... J. . .... .j:.:. ... 67 normal. Adrenals and livers from rats were normal in size at 12 weeks of age and after the reproduction period. Livers from market pigs tended to be enlarged at the 50 and 1007o levels of R.O.M. feeding. On the basis of these trials it may be concluded that: 1. Swine and rats will tolerate levels of R.O.M. as high as 3.9% in the total ration with no detrimental effects. Levels of 7.8 and 15.6% R.O.M. caused decreased rate of gain, lowered efficiency of food utili¬ zation and decreased digestibility of energy, dry matter and nitrogen. 2. Using criteria of rate of gain and efficiency of food utilization, both species of animals were able to adapt themselves to high levels of R.O.M. during the period of growth. This result was presumably associated with an increase in size or number of active cells in the thyroid gland . 3. R.O.M. at the levels fed may be deficient in lysine for swine although the rat trials did not confirm this observation. 4. Extreme caution should be used in feeding R.O.M. to pigs if they are to be used for reproduction purposes. ' ’ . ..... . : .... .... .... .... . r :r; n: ■ . t . ... ' - ' -j;1 . -. ' . : r •• : c . . . .... . ; . . . ... ..... . . £ :f u ... _ ..... 68 BIBLIOGRAPHY ALLEN, C.E., and Dorothy S. Dow. 1952. The biological assessment of the value of rapeseed oil meal as a dietary component. Sci. Agr . 32:403-410. ASTWOOD , E.B., M.A. Greer, and M.G. Ettlinger. 1949. L-5-vinyl-2- thiooxazolidone , an antithyroid compound from yellow turnip and from brassica seeds. J. Biol. Chem. 181:121-130. BAILEY, C.B., W.D. Kitts, and A.J. Wood. 1957. A simple respirometer for small animals. Can. J. Animal Sci. 37:68-72. BARBER, R.S., R. Braude, and G. Mitchell. 1957. Comparison of six different levels of feeding for fattening pigs. J. Agr. Sci. 48:347-354. BARBER, R.S., J.P. Bowland, R. Braude, K.G. Mitchell, and J.W.G. Porter. 1960. Copper sulfate and copper sulphide (CuS) as supplements for growing pigs. Brit. J. Nutrition 15:189-197. BARKER, S.B., M.J. Humphery, and M.H. Soley. 1951. The clinical deter¬ mination of protein bound iodine. J. Clin. Invest. 30:55-62. BARKER, S.B., and H.M. Klitgaard. 1952. Metabolism of tissues excised from thyroxine injected rats. Am. J. Physiol. 170:81-86. BELL, J.M., and J.A. Weir. 1952. Supplementation of alfalfa and marsh hays with linseed, rapeseed and mustardseed oilmeals in gestation rations for ewes. Sci. Agr. 32:496-501. BELL, J.M., and K. Williams. 1953. Growth depressing factor in rapeseed oil meal. Can. J. Agr. Sci. 33:201-209. BELL, J.M. 1955. The nutritional value of rapeseed oil meal: A review. Can. J. Agr. Sci. 35:242-251. BELL, J.M., and E. Baker. 1957. Growth depressing factors in rapeseed oil meal. II Studies on counteraction by dietary supplements. Can. J. Animal Sci. 37:21-30. BELL, J.M. 1957. Growth depressing factors in rapeseed oil meal. Ill Studies in counteraction by steam processing, extraction and supplements. Can. J. Animal Sci. 37:31-36. BELL, J.M. 1957. Growth depressing factors in rapeseed oil meal. IV Comparative feeding values of Argentine and Polish types and the effects of supplementary aureomycin, fishmeal, lysine, iodide and thyroid -active substances. Can. J. Animal Sci. 37:43-49. t c . ■ ... fig . • . . . . . s . ... ... ... .... ■ . .. . - OJ . c « • 69 BENNETT, J.A., and J.H. Coles. 1946. A comparative study of certain performance and carcass characteristics of Yorkshire barrows and gilts. Sci. Agr . 26:265-270. BENSON, G.K., and A.T. Cowie . 1957. Physiology of dairy cattle hormones in reproduction and lactation. J. Dairy Res. 24:252-282. BERG, R.T., and J.P. Bowland . 1958. Restricted feed intake in market swine. Univ. of Alta. Press Bui., Edmonton, Can. 43(2) :4-5. BEZEAU, L.M., S.B. Slen, and F. Whiting. 1960. The nutritional value of rapeseed oil meal for lamb and wool production in mature range ewes. Can. J. Animal Sci. 40:37-43. BLAKELY, R.M., and R.W. Anderson. 1948. Studies with rapeseed oilcake meal. I The effect of various levels of oilcake meal in the diet on the weight of the thyroid gland of turkey poults. Sci. Agr. 28:393-397. BLAKELY, R.M., and R„W. Anderson. 1948. Studies with rapeseed oilcake meal. II The effect of the inclusion of protamone in the diet, on the thyroid enlargement induced by the feeding of rapeseed oilcake meal to turkey poults. Sci. Agr. 28:398-402. BLAKELY, R.M., H.I. MacGregor, and J.R. Jowsey. 1960. Whole rape seed as an energy source in finishing diets for roaster turkeys. Can. J. Animal Sci. 40:67-70. BLAXTER, Kenneth L. 1952. Some effects of thyroxine and iodinated casein on dairy cows, and their practical significance. Vitamins and Hormones 10:217-250. BOWLAND, J.P. 1951. Thiouracil in finishing rations for swine. Univ. of Alta. Press. Bui., Edmonton, Can. 36(2):16-18. BOWLAND, J.P. 1957. Creep feed-prestarter rations for pigs. Univ. of Alta. Press Bui., Edmonton, Can. 42(2) :4-7. BOYD, G.S,, and M.F. Oliver. 1960. Various effects of thyroxine analogues on the heart and serum cholesterol in the rat. J. Endocrin. 21:25-32. BRODY, S. 1945. Bioenergetics and Growth. Reinhold Publ . Corp . , New York, N.Y. BROWN, H., A. Reingold, and M. Samson. 1953. The determination of protein bound iodine by dry ashing. J. Clin. End. and Metab. 13:444-449 . BROWN-GRANT, K. 1958. Thyroid function and adrenal weight in the rabbit. J. Endocrin. 17:197-200. ■■ . c ; ... ■ . . ' J ...... • ' . . 2 . - ..... . V - { • • ■ c ■ . : - , 1 ! . - r: . . : . ■ t * 1 C : - i . v ‘ . r , < ... . . , . • . . . . . 70 CARLE, B„N., and W.H. Dewhirst. 1942. A method for bleeding swine. J. Am. Vet. Med. Assoc. 101:495-499. CARROLL, K.K. 1949. Isolation of an anti-thyroid compound from rape seed. (Brassica Napus L.) Proc. Soc. Expt. Biol. Med. 71:622-624. CHARETTE, L.A. 1961. The effects of sex and age of male at castration on growth and carcass quality of Yorkshire swine. Can. J. Animal Sci. 41:30-39. CLANDININ, D.R. 1949. The effects of methods of processing on the nutritive value of herring meals. Poultry Sci. 28:128-133. CLANDININ, D.Ro, Ruth Renner, and A.R. Robblee. 1959. Rapeseed oil meal studies. Effects of variety of rapeseed, growing environment and processing temperatures on the nutritive value and chemical composition of rapeseed oil meal. Poultry Sci. 38:1367-1372. CLANDININ, D.R., and E.W. Tajcnar. 1961. Rapeseed oil meal studies. 3. Effects of variations in cooking and conditioning tempera¬ tures used during expeller processing of rapeseed on the fat and lysine content of rapeseed oil meals. Poultry Sci. 40:291-293. CRAMPTON, E.W., and G.C. Ashton. 1945. Barley vs wheat as the basal feed in the bacon hog ration. Sci. Agr . 25:403-414. CZARNOCKI, Jo, I.R. Sibbald, and E.V. Evans. 1960. The determination of chromic oxide in samples of feed and excreta by acid digestion and spectrophotometry. Can. J. Animal Sci. 41: 167-179. DAVIS, W.F. Jr., H.D. Wallace, C.E. Combs Jr., and A.C. Warnick. 1959. The use of triiodo thyronine as a lactation stimulant for swine. J. Animal Sci. 18:843-848. DOW, D.S., and C.E. Allen. 1954. Rapeseed oil meal in broiler rations with observations on the nature and control of its metabolic inhibitors. Can. J. Agr. Sci. 34:607-613. DUDLEY, W.A., D.E. Becker, A.H. Jensen, and S.W. Terrill. 1959. The influence of a thyro-active compound in diets for swine during lactation. J. Animal Sci. 18:825-829. DUNCAN, D.B. 1955. Multiple range and multiple F tests. Biometrics 11:1-42. FOSS, O.P., L.V. Honkes, and D .D . VanSlyke. 1960. A study of the alkaline ashing method for determination of protein bound iodine in serum. Clinica. Chemica . Acta. 5:301-326. . . . 'jt'i be : . . . . . - . - '.T . . . . , ... « - - . . - : •- i . . , j ■ . 1 . .. ( , . 71 FREDEEN, H.T. 1953. Genetic aspects of Canadian bacon production. Canada Dept. Agr . Pub. 889, Ottawa, Canada. FROLICH, and F. Haring. 1937. Use of rape residues as protein food for breeding sows. Nutritional Abst. and Rev. 7:4206. GAWIENSKIE, A.M., D.T. Meyer, and J.F. Las ley. 1955. The serum protein- bound iodine of swine as a measure of growth potentiality. J. Animal Sci. 14:3-6. GOERING , K.J., 0.0. Thomas, D.R. Beardsley, and W.A. Curran Jr. 1960. Nutritional value of mustard and rape seed meals as protein source for rats. J. Nutrition 72:210-216. GOULDEN, C.H. 1960. Methods of Statistical Analysis. A Wiley Publica¬ tion in Statistics, John Wiley and Sons Inc., New York, N.Y. GREEP, R.D. Ed. 1954. Histology. The Blakiston Co. Inc., Toronto, Canada . GREER, Monte A. 1950. Nutrition and Goitre. Physiol. Rev. 30:513-548. GR0SVEN0R, Clark E. 1961. Thyroid hormone secretion rate and milk yield in lactating rats. Am. J. Physiol. 200:483-485. HILL, F.W., and D.L. Anderson. 1958. Comparison of metabolizable energy and productive energy determinations with growing chicks. J. Nutrition 64:587-603. HUSSAR, Nick. 1958. Rapeseed oil meal studies with swine and rats. M.Sc. Thesis. Univ. of Alberta, Edmonton, Canada. HUSSAR, N., and J.P. Bowland . 1959. Rapeseed oil meal as a protein supplement for swine and rats. I Rate of gain, efficiency of food utilization, carcass characteristics and thyroid activity. Can. J. Animal Sci. 39:84-93. HUSSAR, N., and J.P. Bowland. 1959. Rapeseed oil meal as a protein supplement for swine and rats. II Energy and nitrogen digesti¬ bility and nitrogen retention. Can. J. Animal Sci. 39:94-101. JOHNSON, C.W., V.W. Hays, V.C. Speers, and D.V. Catron. 1959. Thyro- protein for lactating sows. J. Animal Sci. 18:1224-1232. JONES, G.E.S., E. Delfs, and E.C. Foote. 1946. The effect of thiouracil hypothyroidism on reproduction in the rat. Endocrin. 38:337-344. KENNEDY, T.H., and H.D. Purves . 1941. Studies on experimental goitre. I The effect of brassica seed diets on rats. Brit. J. Expt. Path. 22:241-244. 72 KLAIN, G.J., D.C. Hill, H.D. Branion, and Jean A. Gray. 1956. The value of rapeseed oil meal and sunflower seed oil meal in chick starter rations. Poultry Sci. 35:1315-1326. KONIGSBERG, I.R. 1958. Thyroid regulation ofprotein and nucleic acid accumulation in developing skeletal muscle of the chick embryo. J. of Cellular and Comparative Physiology 52:13-42. KRATZER, F.H., P.N. Davis, D.E. Williams, and B.J. Marshall. 1954. Factors influencing the growth of chicks and poults fed rations containing rapeseed oil meal. J. Nutrition 53:407-418. KROHN, P.L., and H.C. White. 1950. The effect of hypothyroidism on reproduction in the female albino rat. J. Endocrin. 6:375-385. LIKUSKI, H.J.A. 1959. Energy utilization and nitrogen retention by swine and rats fed rations varying in energy and protein level. M.Sc. Thesis Univ. Alta., Edmonton, Canada. LUCAS, J.J., G.E. Brunstad, and S.H. Fowler. 1958. The relationship of altered thyroid activity to various reproductive phenomina in gilts. J. Endocrin. 17:54-62. MAGRUDER, N.D., W.C. Sherman, and W.M. Reynolds. 1962. Evaluation of supplemental lysine for practical swine rations. J. Animal Sci. 20:573-577. MAQSOOD, M. 1952. Thyroid functions in relation to reproduction of mammals and birds. Biol. Rev. 27:281-319. MARINE, D., E.J. Baumann, and B. Webster. 1930. Occurrence of antigoit- rogenic substances in plant juices. Proc. Soc. Expt. Biol. Med. 27:1029-1031. McWARD , G.W., D.E. Becker, H.W. Norton, S.W. Terrill, and A.H. Jensen. 1959. The lysine requirement of weanling swine at two levels of dietary protein. J. Animal Sci. 18:1059-1066. MONEY, W.L. 1955. The thyroid: Brookhaven Symposia in Biology. No. 7:137. MOORE, J.H. 1957. The effect of diurnal variations in composition of the faeces of pigs on the determination of digestibility coefficients by the chromium-oxide method. Brit. J. Nutrition. 12:24-34. MORRISON, F ,B . 1959. Feeds and Feeding. 22nd Ed. The Morrison Pub. Co., Ithaca, New York. National Bacon Hog Policy. 1959. Record of performance for swine. Canada Dept, of Agr . • • < . . • .. . : i ' - . .... C • . : - .v- .. ■ . . . . . }:.:*■ .. , . . . . ■ , . .. . . . , c . . . . c \ 73 National Research Council. 1959. Nutrient requirements of swine. No. II. Pub. 648. NICHOLLS , Doris, and R.J. Rossiter. 1955. The role of the pituitary and thyroid glands in the phosphorous metabolism of the adrenal gland during cold stress. Endocrin. 56:547-559. PARROTT, M.W., M.E. Johnston, and P.W. Durkin. 1960. The effects of thyroid and parathyroid deficiency on reproduction in the rat. Endocrin. 67:467-483. PETTIT, J.H., S.J. Slinger, E.V. Evans, and F.N. Marcellus. 1944. The utilization of sun flower seed oil meal, wheat distillers' grains and rape seed oil meal in poultry rations. Sci. Agr . 24:201-213. PIPES, G.W., B.N. Premachandra , and C.W. Turner. 1958. A technique for estimation of the effectiveness of goitrogens in cattle. J. Animal Sci. 17:227-234. PITT-RIVERS, Rosalind. 1950. Mode of action of antithyroid compounds. Physiol. Rev. 30:194-205. PITT-RIVERS and Tata. 1959. The Thyroid Hormones. Pergamon Press, London . PLANK, R.N. 1961. Relationships among swine carcasses. M.Sc. Thesis. Univ. of Alta., Edmonton, Canada. REID, C., and Jane Kossa. 1954. The action of anti- thyroid agents and thyroxine on tissue homogenates. Archives of Biochem. and Biophysics. 53:321-325. RENNER, R., D.R. Clandinin and A.R. Robblee. 1955. Factors affecting the nutritive value of rapeseed oil meals. Poultry Sci. 34:1233. REINEKE, E.Po 1946. Thyroactive iodinated proteins. Vitamins and Hormones. 4:207-253. SIBBALD, I.R. 1957. Energy and nitrogen retention in the food of the weanling rat. Ph.D. Thesis. Univ. of Alta., Edmonton, Canada. SOLOMON, David H., and J. Thomas Dowling. 1960. The thyroid. Ann. Rev. Physiology. 22:615-650. TAPLEY, D.F., C. Cooper, and A.L. Lehninger . 1955. The action of thyroxine on mitochondria and oxidative phosphorylation. Biochemica et Biophysica Acta. 18:597-598. TAPLEY, D.F. 1956. The effect of thyroxine and other substances on the swelling of isolated rat liver mitochondria. J. Biol. Chem. 222:325-339. . . • - 1 . . . : • • . _ _ . - ' ( : Q . . . . . . . . t - . . - p. . « <. o © ■ r to . . . . . . . , . .. , . , ....... 1 • S. ... . c . :.v. c ....... . •-a : . . i : 5 . - - V . ■ - - .... . . ' 74 TAPLEY, D.F., and C. Cooper. 1956. The effect of thyroxine and related compounds on oxidative phosphorylation. J. Biol. Chem. 222: 341-349. The Feeding Stuffs Act and Regulations. 1952. Canada Dept, of Agr . Queens Printer, Ottawa, Canada. VAN MIDDLESWORTH , L., G. Jagiello, and W.P. Vanderlaan. 1959. Observations on the production of goiter in rats fed propylthiouracil and on goiter prevention. Endocrin. 64:186-190. ZESSIN, D.A., C.V. Pohl , G.D. Wilson, and C.E. Weir. 1961. Effect of pre-slaughter dietary stress on the carcass characteristics and palatability of pork. J. Animal Sci. 20:871-875. ■ ? . i . • . jB * • : - • : , . . , , . „ . . . = • B29802