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This review will discuss the uses of avian models, particularly the chicken, to examine nutrition-endocrine interactions. The chicken has been employed extensively to examine nutritional effects. The effects of fasting, protein deficiency and calcium deficiency on endocrine status have been the subject of intense investigation in young chicks and adult female chickens. The ratio of circulating concentrations of triiodothyronine (T3) and thyroxine (T4) is substantially changed by fasting or protein deficiency. Similarly, protein deficiency reduces circulating concentrations of insulin-like growth factor I (IGFI) while protein deficiency increases growth hormone (GH). Moreover, protein deficiency increases the sensitivity and responsiveness of adrenocortical cells. The chicken also as advantages for studying diabetes, endocrine pancreatic functioning due to the splenic lobe of the pancreas being predominantly endocrine in nature, and the cellular mechanism of GH on chicken adipose tissue. The adult female chicken with its high calcium requirement is a unique system for examining nutritional effects on reproduction.

Growing chickens were fed three levels of biotin, 0, 20, and 100 micrograms/kg diet, and four different carbohydrates, glucose, dextrin, sucrose, and sorbitol, in order to study the effect of dietary carbohydrates on the level of cecal biotin. Dietary sorbitol was found to enhance the concentration of cecal biotin at suboptimal levels of dietary biotin, while dietary dextrin had the opposite effect. When the dietary requirement of biotin was met, cecal biotin greatly increased in the presence of dietary glucose, sorbitol, and sucrose but remained at a low level when dextrin was the dietary carbohydrate. Dietary sorbitol increased significantly the dry weight of ceca over those of birds fed other carbohydrates.

Two- to three-week-old broiler chicks were fed isocaloric purified diets with varying levels of protein (soy protein supplemented with glycine and methionine). The growth rates of the birds were monitored throughout the period of 14 days on the purified diets, while the circulating concentrations of growth hormone (GH) were determined at the end of this period. As expected, decreases in the dietary protein level were associated with concomitant reductions in growth rate. While this decrease in growth rate was observed with chicks fed 12 and 18% protein (compared with 24%), circulating concentrations of GH were observed to be only elevated with severe protein restriction (10% and lower). There was also evidence for some progressive increase in plasma concentrations of GH as dietary protein levels were decreased.

Over a 22-week period, young female rats in conventional cages gained significantly more weight than rats housed with free access to running wheels. A trend toward increased bone density was indicated in runners. In a second test, young female rats were housed under the same conditions for 30 weeks, but the active group was then forced to run in a treadmill for 30 minutes, 5 times a week, over a 43-week period. During this time rats were fed either diets providing adequate Ca (0.5%) and adequate P (0.4%) or high P (1.2%), or low Ca (0.3%) and high P (1.2%). Running appeared to benefit long bone density but could not completely compensate for a high P or a low Ca, high P intake. A bone that received only indirect stress during exercise (atlas) was not significantly affected by running. However, a high P diet significantly decreased atlas bone density, while the negative effect of this diet on the density of long bones was at a lower level of significance. A low Ca, high P diet clearly decreased bone density in all bones investigated. Running had no effect on kidney mineralization, but either a high P or low Ca, high P diet greatly increased the concentration of these minerals in the kidney.

The energetic costs of egg production are considered, as is the relationship between egg production and feed intake. Hens feed during the photophase with a peak in consumption prior to the scotophase. This pattern of intake, followed by nocturnal fast, would be expected to lead to an energy deficit at night. However, much of the energy requirement of the night is met by utilization of feed stored in the upper gastrointestinal tract. It is presumed that some nocturnal energy deficit occurs and is met by changes in metabolism and endocrine balance. The hormonal involvement in these changes in avian metabolism is discussed.

Adult rats were fed isonitrogenous diets (5 % protein equivalent) providing indispensable amino acids either in the whole-egg protein pattern or in the adult rat maintenance pattern of Smith and Johnson (S & J, Brit. J. Nutr. 21 : 17, 1967). In two separate experiments the threonine and the methionine (total sulfur amino acid) requirements were assessed. Similar responses were obtained with rats on the threonine experiment independent of the pattern of indispensable amino acids fed. In the methionine experiment the rats fed the S & J pattern showed a lower need for this amino acid than the rats fed the egg pattern . When the latter group was switched to the S & J pattern, they too required less methionine . In the experiment with college students (female) fed 7 g of nitrogen/subject per day, the lysine requirement on the whole-egg pattern was compared to the requirement on a pattern equal to twice the previously published requirements for young women. No evidence was obtained over the relatively short experimental period that the lysine requirement differed substantially with change in the pattern of indispensable amino acids. Am. I. Clin. Nun'. 30: 932-938, 1977.

The right femurs of adult female rats were bound to their chests over a 14 week period. During this time rats were fed diets providing adequate calcium (Ca) and adequate (0.4%) or high (1.2%) phosphorus (P). Rats fed the high P diet tended to lose more weight during the experimental period than rats fed the adequate P diet. Both immobilization and a high P diet significantly reduced bone density. Thin cortical widths of rats fed the high P diet were apparently due to an increased medullary width rather than to a decreased subperiosteal width, while the reverse was true for the immobilized femur as compared to that of the mobile limb. A high P diet greatly increased the concentration of Ca and P in the kidney.

The effect of dietary protein level on reducing body protein losses following trauma was studied in two age groups. Mature (4-month old) and aged (24-month old) Fischer 344 male rats were given a 20% casein diet for 7 days before traumatization by laparotomy under sodium pentobarbital anaesthesia. After surgery, the rats were given 5, 10, 20 or 40% casein diets. Nitrogen balance studies (N intake-N output in urine, feces and hair) were carried out during the last 3 days pre-trauma and 5 days post-trauma periods. Traumatization by laparotomy significantly reduced N retention of rats. Aged rats retained significantly less N than mature ones during both pre- and post-trauma periods. As the casein level of the diet increased, N retention of rats increased linearly. Except in non-traumatized mature rats, those given a 20% casein diet retained significantly more N than rats given a 10% casein diet; the difference in N retention between the rats consuming the 20% and 40% casein diets was not significant, except for the non-traumatized mature rats. The results show that a relatively high protein level during the post-trauma period reduces body protein losses and that aging compounds the effect of trauma with respect to N loss.

SummaryDay-old cockerels were fed a control or a candicidin-containing diet (0.01%) with or without cholesterol in the form of whole egg powder. The birds were maintained for 18-27 months on their respective regimens and plasma cholesterol was measured at different intervals. At 6 and at 18 months cholesterol-fed birds were killed and the coronary arteries and the aorta evaluated histologically for atherosclerosis. The birds on the cholesterol-free diets were killed after 27 months and similarly evaluated. Initially, in the cholesterolfed birds, plasma cholesterol was drastically reduced below that of the controls by candicidin feeding. However, the plasma cholesterol level of the controls then decreased, and the differences in cholesterol concentration between candicidin-fed and control birds became smaller or nonexistent. No differences in plasma cholesterol occurred at any time in the cocks on the cholesterol-free diet. A lower incidence of coronary artery lesions and a lower severity and incidence of ...

THERE have been few reports of body composition analyses for chickens, particularly for birds more than 1 year old Mitchell et al. (1931) studied the chemical composition of Leghorn males and females in considerable detail up to the age of 40 weeks. Fisher and Griminger (1963) analyzed the carcasses of 38 month old Leghorn males that had been maintained on either ad libitum or a restricted feeding regimen. Several investigators have reported the incidence of atherosclerosis in older chickens (Katz and Stamler, 1953; Fisher et al., 1959, 1960). Weiss (1958) observed a greater severity of atherosclerosis with increasing age for both male and female Leghorn chickens. In the present study, Leghorn hens, 1 to 5 years old, were chemically analyzed for nitrogen, extractable lipid, and moisture, and the severity of aortic atherosclerosis was assessed. EXPERIMENTAL All hens originated from the same genetic stock (Cornell-Random). They were reared in floor pens…

IT IS now a well accepted fact that the breast muscles of flying birds utilize fat as the major fuel for energy during sustained flight. It has been estimated by George and Jyoti (1955) that at least 77% of the energy expended in a pigeon subjected to sustained muscular activity is due to the oxidation of fat. Similarly, Visscher (1938) has shown that the heart obtained nearly all its energy from fat. George and Vallyathan (1964) observed that stimulation for 1 hr. of the breast muscle of pigeons brought about a decrease in the plasma free fatty acids level with a subsequent increase in the muscle. Carlson (1967) also has reported changes in the FFA level of the blood during sus-stained exercise in humans. This information led us to ask which dietary nutrient, fat or carbohydrate, could serve as a more efficient source of energy to racing homers under actual…

Summary Day-old Leghorn cockerels were given a diet containing egg powder and supplemented either with pectin or non-nutritive fiber. After 24 weeks on the diets, the pectin-fed birds had significantly lower blood levels of plasma cholesterol, eliminated more lipid and cholesterol in their excreta, and had a significantly lower incidence and severity of atherosclerosis as measured macroscopically and histologically. Using carmine as a marker, food was observed to pass faster through the alimentary tract of the pectin-fed birds. Throughout the study, the pectin-fed birds consumed more feed than the controls, despite the fact that the former grew more slowly during the early stages of development than the latter. The results suggested that pectin may be effective in reducing the incidence and severity of both spontaneous and cholesterol-induced avian atherosclerosis. The present study suggests that pectin acts by accelerating the transit of food through the alimentary tract resulting in an increased excretion of possible atherogenic substances, as well as of total nutrients (calories).

SummaryThe plasma cholesterol-lowering activity of whole ground oats and its components was studied in chicks fed hypercholesterolemic diets. Oat hulls were most effective whereas oat starch and oat oil had no cholesterol-lowering activity. Liver lipids and cholesterol were also significantly reduced by whole oats and oat hulls, and, to a lesser extent, by dehulled oats. In contrast to observations made with pectin or scleroglucan, fecal lipids and sterols were not increased by the feeding of whole oats or oat hulls.

MENADIONE sodium bisulfite, a water-soluble form of the provitamin 2-methyl-1,4-naphthoquinone, is used as a source of vitamin K in poultry feeds. This form differs in its vitamin K activity from the fat-soluble menadione (Frost and Spruth, 1955). The data presented in this report indicate that this difference is not necessarily a function, or, at least, not only a function of the change in solubility status, since another water-soluble form of menadione, namely, menadione dimethyl pyrimidinol bisulfite, 2 differs in its activity from menadione sodium bisulfite. EXPERIMENTAL Fourteen groups of 20 cross-bred, female chicks received a purified vitamin K-deficient diet (Griminger, 1962a) from hatching to 1 week of age. At that time group uniformity was increased by eliminating 4 chicks with extreme weights. From 1 to 3 weeks of age the chicks received the K-deficient diet supplemented with 0.2% sulfaquinoxaline and with seven graded levels of each of the two water-soluble menadione…

IN the classical bioassay for vitamin K, plasma prothrombin times of chickens fed assay material are compared to those of chickens receiving graded levels of the vitamin. The assay is based on the assumption that the velocity of the clotting process is a function of the level of prothrombin (and factor VII) in the blood, and that the levels of these vitamin K-dependent factors reflect the amount of ingested vitamin K. For this bioassay the growing chicken is the animal of choice, since intestinal synthesis of vitamin K, of importance in some species, plays only a minimal role in the chicken’s vitamin K supply. In the one-stage prothrombin time determination (Quick, 1966), the clotting of decalcified plasma is timed after the simultaneous addition of Ca++ and a source of thromboplastic activity (“thromboplastin extract”), the latter supplying the phospholipid-protein complex necessary for the conversion of prothrombin to thrombin. Acetone-extracted chicken brain…

THE calcium needs of the laying hen can be met by furnishing the required calcium in the feed, by free-choice offering of a calcium supplement, or by a combination of both. The calcium requirement of a laying hen is largely determined by the fraction of dietary calcium retained and by the amount of egg shell secreted (Hurwitz and Griminger, 1962). Since the latter depends upon rate of egg production, size of eggs, and thickness of shell, considerable variability is to be expected among hens. When the calcium requirement is expressed as a percent of the ration, feed intake, and therefore caloric density of the ration, will constitute an additional factor (Griminger, 1961). In view of these variables adjustment of the calcium intake by a free-choice offering of calcium supplements appears to offer a logical solution to the problem of supplying the right amount of calcium for each hen, provided, of…

Pyruvate carboxylase purified from calf liver contains bound magnesium and bound manganese in a combined stoichiometry equivalent to the biotin content of this enzyme. Both metal ions are well correlated with enzymic activity when this enzyme is fractionated on columns of DEAE-Sephadex A-50 (SO42-) or Sephadex G-200. The bound metal status of this mammalian liver pyruvate carboxylase, therefore, differs from the pyruvate carboxylases purified from chicken (Scrutton, M. C., and Mildvan, A. S. (1968) Biochemistry 7, 1940) and turkey liver which are identified as manganese metallo-biotin enzymes. Magnesium replaces manganese as the bound metal of pyruvate carboxylase purified from the livers of chickens which have been raised on rations deficient in manganese. The relative content of magnesium and manganese in the purified enzyme reflects the manganese content of the ration on which the chickens were raised. When the ration containing the lowest level of manganese (0.3 mg per kg) is fed, the pyruvate carboxylase obtained is a magnesium metallobiotin enzyme. Substitution of magnesium for manganese occurs with retention of catalytic activity and causes only minor alterations in the catalytic properties of pyruvate carboxylase. Properties which are affected by the substitution include the apparent Km for pyruvate and the concentration of oxalate required for 50% inhibition of the over-all reaction. In the case of inhibition by oxalate the effect observed is in accord with predictions based on the properties of model complexes.

The second saline extract (E2) of acetone-dehydrated chicken brain powder contained less than one fifth of protein and phosphorus, compared with the first extract (E1). Thromboplastic activity (TPA) of E2 from vitamin K-deficient donors was significantly higher than of E1. Response with vitamin K-sufficient donors varied. E1 and E2 from normal chicks contained significantly more protein than those from vitamin K-deprived ones. P content differed significantly in E1 only. Differences in TPA could not be quantitatively attributed to differences in protein and P content. TPA of brain powder, repeatedly extrasted with saline, declined, as did protein and P content. The addition of normal chick plasma returned TPA of repeatedly extracted brain powders to level found in fresh samples. Extracting samples of equal quantity of brain powder with increasing volumes of saline yielded higher TPA than when saline extract from a single brain powder sample was diluted with saline to produce, in effect, the same dilution ratios.

ConclusionIncreasing doses of vit. K-active compounds are necessary to overcome the inhibition of prothrombin formation in chicks fed increasing levels of sulfaquinoxaline. The drug will hasten depletion of prothrombin in chicks kept on a K-deficient ration. When a single dose of about 50 mg of sulfaquinoxaline was administered orally with varying levels of menadione, one mole of menadione appeared to overcome the inhibitory effect of more than 800 moles of sulfaquinoxaline.

HENS will transfer more vitamin K activity to the chick via the egg when fed phylloquinone (vitamin K1) than when given equivalent amounts of 3-methyl-1, 4-naphthoquinone (menadione). This has been demonstrated under both field and laboratory conditions (Brubacher et al., 1959; Griminger, 1964). It was the purpose of the work reported here to try and explain this observation. METHODS An experimental ration devoid of supplemental vitamin K1 was fed to two S.C. White Leghorn hens. The ration consisted (in percent) of rice starch, 63.0; casein, 19.0; dl -methionine, 0.5; glycine, 0.5; lard, 3.0; ground chalk, 3.5; corn oil, 2.0; mineral mixture, 5.0; and vitaminized starch, 3.5. The mineral mixture consisted (in percent) of sodium chloride, 4.975; calcium lactate, 34.825; tricalcium phosphate, 14.925; ferric citrate, 3.194; potassium iodide, 0.090; copper sulfate, 0.030; magnesium sulfate, 5.472; potassium phosphate, 26.394; sodium phosphate, 9.552; zinc carbonate, 0.020; manganese sulfate, 0.520; sodium fluoride, 0.03. The vitamin …

Growing cockerels were fed diets varying in level of protein and cholesterol and in the type of fat. Their plasma and aortas were examined for cholesterol, polynsaturated fatty acids, and atherosclerotic involvement.

INTRODUCTION THE existence of a dietary vitamin K requirement for species of birds other than Gallus gallus has been recognized for considerable time (Dam et al., 1937). Although Almquist stated in 1939 that turkeys were subject to vitamin K deficiencies, no data appear to exist comparing the turkey poult’s requirement with that of the chick. Exact measurements of vitamin K requirements are made difficult by the presence of residual amounts of the vitamin in the experimental rations, by coprophagy, and possibly by intestinal synthesis of vitamin K. As considerable experimental work has been done with the chick, comparisons of the requirements of the two species would appear to be of interest. The experiments reported in this paper have been undertaken in order to obtain an estimate of the requirement of turkey poults for vitamin K, and the efficiency of a water- and a fat-soluble form when compared by a curative . . .

Three groups of adult cocks were exposed respectively to 2, 21, and 32 C temperatures for a 15-month experimental period. Food consumption, body weight, body composition, feather composition and weight, atherosclerosis and fatty acid composition of plasma, liver and depot fat were studied. It was found that with the use of a pelleted diet the cold-exposed cocks maintained the same body weight as the control group (21 C). The heat-exposed birds were lighter in weight than either controls or cold-exposed and had significantly less body fat and water. Severity of atherosclerosis was not affected in the cold-exposed cocks, despite greatly increased caloric intake. The liver fat of the cold-exposed cocks was significantly higher in di- and hexaenoic acids than that of the controls or heat-exposed birds. The depot fat of heat-exposed birds was lower in monoenoic and higher in dienoic acid than that of controls or cold-exposed birds. The cold-exposed cocks also had significantly more feathers and feather lipid than the other two groups. fatty acid composition; depot fat temperature; feathers Submitted on November 23, 1964

Summary The feeding of different rations to 20-month old Leghorn chickens for a period of 18 months resulted in a significant increase in the severity of abdominal aortic atherosclerosis in birds given an egg-enriched, balanced poultry ration, or the control ration supplemented with dicumarol. When birds were given a diet prepared from Army C rations and certain supplements to insure its nutritional balance and palatability, a significant decrease in aortic involvement was observed compared with that of controls or birds on the other treatments. It is suggested that the relatively high pectin and peanut oil content of the ration may be implicated. Additions of vitamin K 1 or of a combination of vitamins A, E and B 6 did not influence the degree of aortic atherosclerotic involvement.

IN ANIMAL feeding practice, arsenicals are being widely used as additives, and considerations regarding the safety of their use in poultry feeds have been discussed by Frost (1953). While the toxicity of arsenic-containing compounds is well known, it has also been reported that even the low doses of arsanilic acid (p-amino-phenylarsonic acid) and arsonic acid (3-nitro-4 hydroxy-phenylarsonic acid) commonly used in poultry rations might increase the blood clotting time of the chicken and cause hemorrhages (Griminger et al., 1953; Sweet et al., 1954; Nelson and Norris, 1959). Anderson et al. (1954) and Frost et al. (1958), however, did not observe any effect on blood clotting. In the light of such disagreements it seems appropriate to re-examine the possible influence of arsanilic acid on blood coagulation. EXPERIMENTAL Female crossbred chicks were fed a semi-synthetic basal ration, deficient in vitamin K-active compounds (Table 1), from the day of hatch to one week …

Copper sulfate supplementation at 0.2% or more of the diet depressed feed intake and body weight and decreased egg production and egg shell thickness. No significant effect on egg parameters was observed at the 0.1% level of supplementation.

Womack and Rose (1947) have shown that moderate growth occurs in the rat when arginine, proline and glutamic acid are excluded from an otherwise complete diet. Their work, as well as the earlier work of Clutton et al. (1940), Roloff et al. (1940) and Stetten and Schoenheimer (1944) also indicates that glutamic acid and proline can be interconverted to arginine and therefore spare the latter amino acid. Klose et al. (1938) determined that arginine was an essential amino acid for the growing chick. The possible sparing effect of glutamic acid and proline has not been investigated in the chick. The data herein reported indicate that arginine is an indispensable amino acid for growth as well as for maintenance of nitrogen balance in the adult rooster and that neither proline nor glutamic acid singly or in combination exert any sparing effect on the arginine needs of the arginine needs of the …

Becker et al. (1954a) have shown that newborn pigs can neither hydrolyze sucrose nor can they utilize fructose. However, early in life piglets develop the capacity to utilize sucrose (Becker et al., 1954b) and, according to Kidder et al. (1963), at an age of 17 days they appear to have the ability to completely hydrolyze sucrose. Mitchell et al. (1937) observed a slight impairment in the digestibility of organic nutrients in a sucrose ration for rats, as compared with a ration containing glucose, and a slower rate of growth and of protein deposition on a fructose-containing ration. In the same species, Ruttloff and Ketz (1961) observed a decreased absorption rate for fructose as compared with glucose. In the chicken, the protein level has been shown to play a role in the comparative utilization of carbohydrates, sucrose diets promoting a growth rate equivalent to that obtained with dextrin diets on high-…

Summary and conclusionMale chickens were fed for 6 months on rations containing (a) no supplement, (b) cholesterol plus corn oil, (c) cholesterol plus corn oil-sterol and (d) cholesterol plus fatty acids rich in linoleic acid. Atherosclerotic severity tended to be greatest in the group given fatty acids and least on the sterol-containing diet. Since sterol excretion indicated a similar rate of cholesterol absorption on the cholesterol-supplemented diets, it appears that the principle in corn oil which retards avian aortic atherogenesis is present in the sterol fraction.We gratefully acknowledge the help of Dr. V. K. Babayan, E. F. Drew and Co., Boonton, N. J. for supplying us with the fatty acid fraction and that of Dr. S. S. Chang, Staley Mfg. Co., Decatur, Ill. for providing corn oil sterols used in this study.

SummaryIt was shown that small concentrations of certain dietary polyene macrolides, and in particular the aromatic heptaenes, effectively reduce plasma cholesterol of cholesterolfed chicks, presumably through a mechanism which involves binding of lipids, particularly cholesterol, in the digestive tract.

Due do a partial species specificity of thromboplastin (Hecht, 1955; Didisheim et al., 1959) it is requisite to use a chicken thromboplastin extract for prothrombin determinations on chicken blood by the one-stage method (Quick, 1957). Whether thromboplastin extracts from other avian species are equally effective is not perfectly clear (Griminger, 1957; Didisheim et al., 1959). Chicken brain thromboplastin extract is usually employed, although embryo extract and muscle extracts have also been used successfully. Although comparable results may be obtained with various extracts (Griminger, 1962b), the material of choice appears to be a carefully prepared chicken brain extract resulting, with the one-stage method, in prothrombin times of 12 seconds or less. For many years we have been preparing brain thromboplastin extracts from chickens that had previously been fed a vitamin-K-deficient diet. Since we felt some question as to the influence of the level of vitamin K nutriture on the thromboplastic activity…

DELAYING sexual maturity in replacement flocks by means of restricted feeding or lighting has long had its advocates. Among the advantages claimed by some, and denied by others, are better body weight when production begins, higher total and more sustained egg production, and larger egg size. (See comments by Platt, 1955; Milby and Sherwood, 1956; Fuller, 1958; Couch, 1959.) It is not the purpose of this paper to debate further the merits or demerits of this management technique; rather it is to suggest that the drug Nicarbazin* may be used to simulate retardation of sexual maturity without restricting feed or light. It has been shown that feeding Nicarbazin at certain levels can temporarily inhibit egg formation in laying birds without depressing body weight or feed intake, and that apparently normal reproductive function is restored shortly after the drug is withdrawn (Sherwood et al., 1956; Baker et al., 1957; Weiss, 1960).

OCCASIONALLY, vitamin deficiency symptoms are observed with purified diets that appear to be adequately fortified with vitamins (Lyman and Elvehjem, 1951; Barnett et al., 1956). Certain salt mixtures used in purified diets appear to have a destructive effect on some vitamins of the B-group, especially on thiamine (Rombouts, 1953; Waibel et al., 1954). Kandutsch and Bauman (1953) suggested that thiamine destruction might take place in an aqueous medium in a film around the ration particles, that atmospheric oxygen is the destructive agent, and that some components of the salt mixture act as catalysts to speed this destruction. They also showed that glycerol, ascorbic acid, and a number of other compounds increased the stability of thiamine. This has led in some instances to the use of ascorbic acid as a stabilizing agent for purified diets. In the following experiments a purified diet was fed with different mineral- and vitamin mixtures, with …

SummaryA study with growing chicks and adult roosters indicated that dietary saponin will depress blood plasma cholesterol previously elevated by feeding low protein levels in presence and absence of dietary cholesterol. It is suggested that complexing of saponin with cholesterol secreted in the intestinal lumen makes less cholesterol available for reabsorption from the intestinal tract.

SummaryChicks from hens from a random-bred flock were raised to 4 weeks of age on either an arginine- or a lysine-deficient diet. The results showed an inherited growth potential for chicks given either amino-acid-deficient diet. In most cases, offspring of any one dam behaved differently on the 2 deficient diets. The ranking of dams on the basis of growth potential of offspring given a complete ration was similar to that obtained on the arginine- but not the lysine-deficient ration. The coefficient of variation of 4-week weights was greatest on the arginine-deficient diet and least on the complete diet.

Following fracture of the femur, changes in nitrogen retention and mineral tissue concentrations in response to graded levels of dietary copper, manganese, and zinc were investigated. Retained nitrogen and liver copper, manganese, zinc, nitrogen and glycogen were determined prior to trauma and at 48-hour intervals for 8 days posttrauma. The excretion of nitrogen increased, and liver copper,manganese, and zinc decreased, as did liver nitrogen and glycogen in response to fracture. Increasing dietary copper, manganese, or zinc increased liver copper, manganese, or zinc, respectively, and decreased nitrogen loss by traumatized rats. The data suggest that trauma induced a change in the concentrations of liver copper, manganese, and zinc which coincided with changes in liver nitrogen and glycogen. The results indicated that subsequent to femoral fracture, the nutritional requirement for copper, manganese, and zinc for minimal nitrogen loss were higher than the NRC requirements for the mature male rat.

Oxidation products of cholesterol, which have been observed to be formed in powdered eggs and other dehydrated cholesterol-containing foods, have been suspected as the probable primary cause of atherosclerotic lesions. The feeding of powdered vs. fresh egg yolks to young male chickens up to 30 and 43 weeks of age, respectively, produced approximately the same increase in plasma cholesterol, liver fat, and liver cholesterol when compared to the feeding of a soybean-based cholesterol-free diet. Aortic atherosclerosis, however, was found to be more severe in a group of birds fed fresh egg yolks than in those fed powdered egg or the cholesterol-free diet. A previously demonstrated, enhanced feedback inhibition of cholesterol synthesis by oxidized cholesterol derivatives may at least partly explain these results.

The effect of protein-calorie restriction on the circulating concentration of luteinizing hormone (LH) was investigated in the young domestic fowl. Two-week-old broiler chicks were fed isocaloric synthetic diets with varying levels of soy protein for a period of 14 days. Growth rate, as indicated by body weight, was decreased as the level of protein in the diet was reduced. Body weights of birds on a 3% protein diet were only 29.7% that of birds on a 24% protein diet. Severe protein-calorie restriction was also associated with depressed plasma LH levels in birds of both sexes, with male birds appearing to be more sensitive to this deficiency. A reduction of protein in the diet from 24% to 3% was associated with a 69% decrease in LH in males and a 43% decrease in females. In addition to lower circulating concentrations of LH, protein-calorie restriction was associated with a reduction in gonadal weight. Testes weights in birds on a 3% protein diet were only 16% of those on a 24% protein diet. Studies with synthetic luteinizing hormone releasing hormone (LHRH) indicated that protein-calorie restriction alters luteinizing hormone secretion via a hypothalamic effect.