The physiological effects of excess vitamin A are frequently studied in the investigation of the systemic function of the vitamin. The liver vitamin A storage efficiency of dietary excesses of vitamin A and the effect of excesses of the vitamin on alimentary cholesterolemia, the one-stage prothrombin time and the one-stage euglobulin lysis time were investigated in several genetically distinct populations of chickens. Birds of a New Hampshire (NH) line were found to store vitamin A in the liver from the diet more efficiently than birds of three White Leghorn (WL) strains (D,K and B) and of one broiler strain. An excess of dietary vitamin A reduced alimentary cholesterolemia in the NH chicks but increased alimentary cholesterolemia in the D chicks. There was no effect of hypervitaminosis A on the blood cholesterol concentration of either the D or the NH chicks receiving a low-cholesterol diet. No carryover effect of vitamin A upon removal of the excessive quantity of the vitamin from the diet, could be demonstrated on alimentary cholesterolemia in either the D or the NH chicks. The efficiency of the intestinal absorption ofcholesterol was increased in both the NH and the D chicks by an excess of vitamin A. The liver-to-blood partition ratio of cholesterol was increased by excess vitamin A administration in the NH chicks, but was decreased by excess vitamin A in the D chicks. The one-stage prothrombin time of D,K,B, and NH chicks was unaffected by the dietary administration of large excesses of the vitamin from day-old to three weeks of age. Chicks of a Black Australorp (A) line, however, responded to large excesses of the vitamin in the diet with an increase in one-stage prothrombin time. A single intramuscular injection of menadione (5 mg/kg body weight) brought the prolonged prothrombin times of the A chicks to normal within twenty hours. The one-stage euglobulin lysis time of NH,D and A chicks was decreased by the inclusion of large excesses of vitamin A in the diet of the birds from day-old to six weeks of age. Intramuscular administration of menadione (5 mg/kg body weight) was without effect on the shortened lysis times within twenty-four hours. Removal of the excessive quantities of vitamin A from the diet for six weeks failed to affect the shortened clot lysis times of the A hypervitaminotic chicks. Vitamin K deficiency induced in a Shaver strain of WL chicks by feeding the birds a K-deficient diet, had no effect on the euglobulin lysis time. The results of the present experiments extend knowledge of the effects of hypervitaminosis A on the induction of alimentary cholesterolemia and on the blood coagulation mechanism in the chicken. / Land and Food Systems, Faculty of / Graduate

Four main experiments were carried out to study the nutrient requirements and management of sheep raised in confinement. Experiment I was designed to study the reproductive performance and protein utilization of ewe lambs bred to lamb at approximately 14 to 16 months of age. Rapeseed meal was compared to soybean meal as a source of supplemental protein during the second half of gestation. Ewe weight gains and lamb birth weights were not affected by either the level or the source of protein. Neither dry matter nor protein digestibility were influenced by the stage of gestation of the ewe. No consistent results were obtained with regard to nitrogen retention of the ewes during the last half of gestation. The results suggest that 11% crude protein (CP) in the dry matter supplying approximately 68 g digestible crude protein (DCP) may be adequate for this class of ewes. The results also indicated that a level of 22% rapeseed meal may be included in the diet of gestating ewes without producing goitrogenic or other adverse effects. Experiment II was conducted to assess the performance of ewe lambs during lactation when fed rapeseed meal or soybean meal together with low quality roughage. Weight changes of the ewes and the average daily gain of the lambs over the eight week lactation period were not affected by the level or the source of protein. The results suggest that 10% CP in the dry matter supplying approximately 92 g DCP may be adequate for the class of ewe studied. A level of 25% rapeseed meal may be included in the diet of lactating ewes. In Experiment III wheat and barley were compared as energy sources in all-concentrate rations for lambs weaned at eight weeks of age. The cereal grains were fed in the whole, rolled, and pelleted forms together with a pelleted protein supplement. Digestiblity trials were also conducted to measure the digestibility of energy and protein as influenced by grain, process and level of intake. There was no difference in growth rate of lambs fed wheat or barley. Whole grains resulted in a faster rate of gain than the pelleted form. Digestibility of energy was not influenced by the method of processing. Protein digestibility was similar for the whole and rolled grains with a tendency for pelleting to depress digestibility of this nutrient. Increasing feed intake from maintenance to appetite resulted in a slight depression in nutrient digestibility. The results of this study suggest that processing of cereal grains for lambs is unnecessary from the standpoint of digestibility and would appear to be detrimental in terms of growth rate and feed conversion efficiency. Experiment IV was designed to study the influence of level of protein supplementation of whole barley based rations for early weaned lambs. A series of digestibility studies were conducted to measure the digestibility of dry matter and protein during three periods of growth. Results of this study demonstrated that 16% CP in the ration of lambs from 20 - 29 kg liveweight was sufficient to produce the most economical gain during this period of growth. In the period from 29 - 36 kg the lambs receiving 14% CP in the ration gained faster and had the best feed conversion efficiency. During the final finishing period the results suggest that one could continue to feed a 14% CP ration. The digestibility of dry matter and crude protein were not influenced by stage of growth of the animal. / Land and Food Systems, Faculty of / Graduate

The effect of heat treatment on the protein quality and the metabolizable energy value of rapeseed meal was investigated. Different rapeseed meal samples were autoclaved at 121° c for different times. a significant reduction (p < 0.05) in the in vitro protein digestibility resulted from the autoclaving treatment. Further reduction in protein digestibility occurred when samples were autoclaved with glucose. Poor growth and feed efficiency in the chicks were observed due to feeding of autoclaved rapeseed meal ration. Lysine supplementation of autoclaved and unautoclaved rapeseed meal improved growth and feed efficiency. Maximum growth on the control ration was obtained with 0.16% lysine supplementation whereas 0.24% maximized the growth of chicks on autoclaved rapeseed meal. No significant effect was observed on liver weight expressed as percentage of body weight, however, pancreas weight was significantly greater (p < 0.05) in birds receiving autoclaved rapeseed meal than the controls. There was no significant difference in metabolizable energy value of autoclaved and unautoclaved rapeseed meals. / Land and Food Systems, Faculty of / Graduate

In Part A of Study I, six groups of female standard mink were fed (once daily) either 5, 10, or 15 mcgm. of DES/mink/day or a forage antiestrogen extract at levels of 5, 10, or 15 gm. equivalent of alfalfa/mink/day. In Part B, seven groups of female pastel mink were fed (once daily) 15 mcgm. of DES/mink/ day prior to and at various stages of the gestation period. Also, the antiestrogen extract was again fed (once daily) at levels of 5, 10, or 15 gm. equivalent of alfalfa to three groups of female pastel mink after implantation of the fertilized egg had occurred. From the results of Part A and B of Study I it is evident that DES at levels as low as 5 to 15 mcgm/ mink/day caused complete reproductive failure. At the 15 mcgm. level it is possible to prevent or disrupt pregnancy if the hormone is administered for at least one week during the period starting one week before breeding and ending 30 days prior to parturition. The forage antiestrogen at levels between 5 and 15 gm. equivalent of alfalfa reduced the number of kits per litter from 5.8 to 1.6. The feeding of various levels of DES or the antiestrogen extract did not adhere to a dose/response relationship either in interrupting pregnancy or reducing the number of kits per litter. The DES, fed at levels of 5, 10, or 15 mcgm./mink/ day was a more potent antifertillty agent than the forage antiestrogen fed at levels equivalent to 5, 10, or 15 gm. of alfalfa. In Part A of Study II, 200 mature male and female mink of a variety of colour phases were divided into five groups. The groups were fed (twice daily) rations varying in crude protein (36.6 to 44.8%, on a d.m. basis) and gross fat (21.3 to 28.9%, on a d.m. basis). In Part B, 280 pastel and standard kits (6-7 wks. old) were fed (twice daily) rations varying in crude protein (39.0 to 54.3%, on a d.m. basis) and gross energy (5.20 to 5.52 Kcal/gm. dry feed). From the results of Part A and B of Study II it is evident that rations containing 35 to 40% crude protein and 20 to 25% fat, on a dry matter basis, are satisfactory for the late growth and maintenance requirements of mink. The mean apparent digestibility coefficients obtained in these studies for dry matter, protein, fat, and energy are 66.38, 74.05, 87.20, and 73.74%, respectively. As the apparent digestible energy (A.D.E.) was raised from 353.4 Kcal/100 gm. dry matter to 426.0 Kcal/100 gm. and as the apparent digestible nitrogen (A.D.N.) level reached 4.980 gm/100 gm dry matter, the early growth of both male and female mink was improved. Maximum early growth rate was obtained in kits when the ration contained 85.54 Kcal of A.D.E./gm A.D.N. (13.6 Kcal gross energy/gm gross protein). Also, increasing A.D.E. content in the diets had a definite protein-sparing effect. Maximum nitrogen retention was obtained when the diet contained 426.0 Kcal of A.D..E./100 gm. of dry feed. Finally the results suggest that the growing male kits (from 6-28 weeks of age) were capable of utilizing feeds more efficiently than female kits of the same age. / Land and Food Systems, Faculty of / Graduate

Twenty-eight beef-type animals were divided into four groups and fed four rations consisting of equal amounts of basal ration, to which increments of alder sawdust (Alnus rubra) were added (0, 13%, 21%, and 35%) (Experiment I). The addition of the sawdust had no significant effect on total gain although the three groups of animals receiving sawdust in their diet had a higher rate of gain than the group receiving no sawdust. The effects of the ration on the carcass grade and the acceptability (tenderness and juiciness) of the meat as studied by a trained taste panel, were non-significant. When the rations used in the above trial were subjected to a digestion trial using mature wethers, the results coincided with the growth data collected from the steers used above. If the digestion of the basal rations were taken as constant, the wood material had a digestion coefficient ranging from 46.5% to 13.5%, depending on the level of sawdust in the diet. It was felt that a figure of 13% digestion for sawdust was close to being correct, and that the variation in measurement of the digestion of sawdust was due to the increased utilization of the basal ration when the sawdust was present. Analysis of the rumen fluid of the steers in the growth trial for total and individual volatile fatty acids (VFA) showed a decrease (p<.05) in the molar percent of propionic acid as the level of wood in the diet increased, while the total concentration of VFA and the molar percent acetic acid remained relatively constant. Thirty-six yearling Hereford steers, assigned to six treatments consisting of a basal ration and three roughage sources (hay (H), alder sawdust (W), and extruded alder sawdust (E)), fed at two levels (15% and 20%), were used in a study to determine the effect of heat and pressure treatment of wood on the utilization. The growth of the animals on the H rations was significantly (p< .01) greater than those on the other treatments. The effect of treating the sawdust by extruding it was non-significant although the animals on the extruded wood diet had a slight increase in gain over those on the W ration. The effect of level of roughage was nonsignificant. The effects of level of protein in the diet and the interaction with roughage source were studied. Protein levels of 13% and 15% were studied, along with two roughage sources (hay (H), and alder sawdust (W)), fed at two levels (15% and 20%). The H rations again had a significantly (p<.01) greater gain. The effect of increasing the protein level in the diet was found to be non-significant. When the above rations were subjected to analysis using the in vitro technique, results showed that the H rations had a significantly (p < .01) higher digestion than either the W or E rations. It was also found that the E rations had a higher digestion coefficient than the W rations (p <«05). Increasing the roughage level from 15% to 20% caused a significant (p<.01) decrease in digestion. When the same rations were subjected to an in vivo digestion study using growing wethers, the results were similar to the in vitro study with the H rations having a greater digestion (p <.01) than the W or E rations. However the difference between the W and E rations was non-significant. An equation for predicting the in vivo dry matter digestion is given: In vivo dry matter digestion = 60.1252 + 0.0221 (in vitro dry matter digestion) + 0.4799 (acid detergent fibre) - 3.5855 (lignin) - 0.8395 (cellulose). / Land and Food Systems, Faculty of / Graduate

In recent years research has expanded the knowledge one has of the actual costs Involved in the growth process of meat producing animals. These studies have shown that at the higher weights a larger proportion of the gains are made up of high cost fat tissues. Initially it was thought that this fat deposition served a useful purpose in making meat tender, but it is now known that this original premise was incorrect. Fat is no longer desired by the consumer above a certain minimum level. The feedlot operator therefore has the option of taking advantage of this phenomenon and shipping animals at a lighter weight, at a lower cost, and with the possibility of doing this at a higher profit margin than is the case at present. A study has been made of the total costs involved in the production of a pound of live animal weight under feed-lot conditions and of the changes in these costs that occur as the animal achieves a higher total body weight. It was found that on the average, each additional pound of gain requires between .006 and .028 more pounds of feed than did the previous pound. As a result of these studies, an Economic Shipping Weight was proposed as a means of signifying the beginning of an increase in the average cost of production and hence, a decrease in. the rate of return to investment. The Economic Shipping Weight was defined as that weight at which the feed cost of an additional pound of gain is equal to the current value of a pound of live animal weight. In the application of this theoretically derived shipping weight to a practical feedlot operation having a total fixed investment of $162,938.00, it was found that the total return to investment was increased from $8,822 to $22,503. This increase resulted in a change in the rate of return to investment from 5.44% to 13.81%. The major part of this increase in the total margin was due to a reduction in the average feed cost of each pound of gain from 20.2¢ to 17.4¢. The total margin between sales revenues and animal purchase and feed costs was increased by $5,485.00. This reduction in feed costs was caused by a lowering of the average amount of feed required per pound of gain as the animals were theoretically shipped 41 lb. lighter than in the actual operation. Originally they were sold at an average weight of 998 lb. Seventy-six percent of them received a Choice grade. The analysis was carried out under the assumption that they would only receive a Good grade price at the Economic Shipping Weight. Other savings arose from a reduction in the total interest charges on feed purchases because of the lower total feed consumption, and from a reduction in the total feed freight bill. These two savings amounted to $4,716.00. The remaining saving resulted from a smaller in process feed cost. A study was also made of the relative advantages for the beef industry of stressing the production of Good grade beef as opposed to Choice grade beef. It appears that an economic advantage could be gained by the packing house operators, feedlot operators, and retailers, if this were to become the main grade produced. As consumers are now making most of their meat purchases on the basis of a lack of fat, Good grade meat is also more acceptable to them. The feasibility of using Dairy breed animals as a meat source was examined as a means of producing leaner meat at a lower cost than beef breed meat. These animals were shown to have a definite economic advantage at any body weight because they used feed more efficiently. Dairy breed bulls were also shown to produce meat more economically than any other dairy or beef breed animal and resulted in meat which is more desirable to the consumer. Because of their greater efficiency they had an Economic Shipping Weight of 1050 lb. as opposed to 900-950 lb. for beef breed animals. There was, however, a certain risk involved in their production because of the wide variation in the grades they may receive. / Business, Sauder School of / Finance, Division of / Graduate

Experiments were carried out to determine the effect of breeder diet on the weight of the chick at hatching and up to 4 weeks of age and on the effect of breeder diet and chick diet on body composition of the chick. The dietary treatments imposed were related to protein level and amino acid composition of the breeder diet and the chick diet. Two experiments were carried out in which different sets of dietary comparisons with breeder rations were made. In the first experiment, diets fed to the breeders varied with respect to the source of supplementary protein (soybean meal, herring meal and white fish meal) supplied. The progeny of these breeders showed differences in hatch weight but the differences in weight were no longer statistically significant by the end of the first week after hatching. The breeder diet did not appear to affect the composition of the progeny at hatching or at three weeks of age. In the second experiment the diets fed to the breeders differed markedly in protein level as well as in amino acid composition and in this experiment there were significant treatment effects on the hatch weight of the progeny which persisted until at least four weeks of age. In a third experiment chicks were fed different levels of lysine and the effects on body weight and on weight of the pectoral muscle measured. It was found that the weight of pectoral muscle was more sensitive to dietary lysine level than was total body weight. It was therefore concluded that the ratio of pectoral muscle weight to body weight provides a more sensitive criterion of the lysine adequacy of a chick diet than does body weight. In further study of the effect of the amino acid balance of the breeder diet on embryonic and postnatal growth of progeny the use of this ratio as the criterion of response should be investigated. / Land and Food Systems, Faculty of / Graduate

In the first study 30 Hereford steers were fed a ration of either steam rolled barley or a 50:50 mixture of barley and alfalfa leaf meal pellets. In addition to these basal rations groups of animals on each, were fed a protein supplement with Diethylstilbestrol (D.E.S.) at levels such that each animal received either 0, 10, or 18 mgm. of D.E.S./head/day. The hormone treatment of animals fed the barley ration did not affect the growth rate or feed efficiency but a significant increase in hemoglobin levels from 8.96 to 10.40 gm. % Hb. and in the red cell counts from 8.25 million/mm³ to 9.50 million/mm³ resulted. A similar increase in red cell count from 8.7 million/mm³ to 9.6 million/mm³ resulted from hormone treatment of the animals fed the 50:50 barley-alfalfa ration. There was also an apparent, but insignificant, increase in haematocrits on both rations due to hormone treatment. This treatment resulted in a significant increase in the ratio of blood acetic to propionic acids on the barley ration from 82.3:1 to 195.3:1 but, did not cause a change in total blood volatile fatty acids (V.F.A.). There was an increase in the blood acetic-propionic ratio on the barley-alfalfa ration due to D.E.S. addition. This was from 97:1 to 159:1 at 10 mgm. D.E.S./head/day, to 233:1 at 18 mgm. of D.E.S./head/day but, was insignificant due to high within-group variability. There was an apparent difference between the three blood parameters (Haematocrit, Hemoglobin, Red Cell Counts) on the two control rations due to the higher iron content of the barley-alfalfa ration. This, and an apparent decrease in thyroid weights were shown to be insignificant. In the second study, using an all barley ration and a protein supplement containing a high iron concentration, there was a stimulation in growth rate and feed efficiency due to D.E.S. The animals were started on D.E.S. at 718 lb. (cf. 465 lb. for Study I). The increase in the three blood parameters was again observed on the low iron rations but, on the high iron ration there was an apparent but insignificant decrease in these parameters due to D.E.S. The animals fed the control high iron ration produced an haematocrit and red cell count that was significantly higher than that of the control low iron ration, indicating a possible deficiency in the original supplements. On the low iron ration there was a significant increase in total blood V.F.A. from 0.88 meq./l. to 1.19 meq./l. in response to D.E.S. supplementation but, on the high iron ration the increase was insignificant. The difference between the two control rations (0 D.E.S., high and low iron) total blood V.F.A. was shown to be significant, 0.88 vs. 1.08 meq./l. at P< .05. A method of preparation of feed and liver samples for analysis of their mineral content by atomic absorption spectrophotometry was developed. There was shown to be a significant increase in liver copper storage on the low iron ration with increased levels of D.E.S. The feeding of a high iron ration caused a significant decrease (P< .05) in the level of copper in the liver from 84 ppm. to 37 ppm. A slight but insignificant increase in liver iron levels on the high iron ration and through the treatment with D.E.S. was observed. / Land and Food Systems, Faculty of / Graduate

This study was designed to determine which seral stages of the regenerating coast forest are most efficient at converting radiant energy into energy available as seasonal deer foods, and if the most efficient stages are most intensively used by deer. Populations of Columbian black-tailed deer (Odocoileus hemionus columbianus Richardson) in coastal British Columbia have been reported to reach maximum levels soon after logging and slash-burning, and to decline as. succession advances. The efficiency of a deer range in producing food has been suggested as a factor influencing reproductive success and thus, population density. Seasonal forage preferences were determined, through rumen content analysis. Cover composition up to four feet in height, and summer and winter estimates of quantity, variety and nutrient quality of the important food species were obtained in different seral stages. These data were then related to the intensity to which deer utilized each seral stage, as indicated by the abundance of pellet groups. An early salal-catsear (Gaultheria-Hypochaeris) association develops three to five years after slash-burning. This type was preferred by deer during spring and early summer. Herbaceous plants formed 60 per cent of the spring-summer diet and were represented by more species, covered more surface area, and produced more available forage in this seral stage than in any other. A salal-Douglas fir (Gaultheria-Pseudotsuga) association develops 12 to 15 years after slash-burning. This type was preferred during autumn and winter. Shrub and coniferous species formed 70 to 80 per cent of the autumn-winter diet and were represented by more species, covered more surface area, and produced more available forage in this seral stage than in any other. In addition, the crude protein, mineral, and ash contents of the important evergreen foods were higher when eaten (autumn-winter) than at other times. Heaviest deer use occurred in the seral stages where these evergreens were most available. The nutrient content of key foods changed significantly with season, and there was evidence of selection by deer of the most nutritious plants available. Tests to demonstrate declines in nutrient levels as seral succession advanced between the fourth and fourteenth years were inconclusive, particularly since there is a likelihood of significant declines occurring in the initial four years. However, seasonal and successional changes in food quality are believed to be a factor influencing range selection. It is concluded that the numbers of deer within a logged unit of coast forest are affected by the efficiency at which food is produced. Numbers within the whole community are affected by the availability of ideal food-producing units for each season. A further hypothesis is suggested which states that sustained populations cannot be expected in a logged coast forest because seral succession will inevitably cause regression of range quality. / Science, Faculty of / Zoology, Department of / Graduate

The feeding of three different rations varying mainly in crude fat and crude fiber level at a high level of intake to pregnant and non-pregnant ewes had a number of effects on blood glucose, lactic acid, acetone plus acetoacetate, and total volatile fatty acid concentrations during the last three months of gestation for the pregnant animals (February, March, and April). There was no significant effect due to time on blood glucose level or on the level of blood ketone bodies, during the latter stages of pregnancy, for animals consuming high, medium or low roughage rations. The intramuscular injection of 1 mg./kg. body weight of growth hormone into pregnant sheep for 7 days during the last month of pregnancy, caused no significant effects on blood glucose, lactic acid, acetone plus acetoacetate, or total volatile fatty acids concentrations. / Land and Food Systems, Faculty of / Graduate