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Two experiments were conducted to investigate the effect of dietary salt level on the laying performance of egg-type hens. The results show that when producing hens are fed a diet containing no added salt there was a rapid decline in egg production and a marked decrease in feed intake and body weight. Subsequent feeding of a salt-adequate diet resulted in a rapid resumption of egg production to a level higher than that of the control hens and to a significant improvement in shell and interior quality. There was no evidence in either experiment of any adverse effects due to the feeding of low-salt diets for periods of four to six weeks.

THE reports of Morris et al. (1932), Sheehy (1939), Fuller et al. (1940), Heuser et al. (1945), Carrick and Roberts (1947) and Insko and Culton (1949) generally agree that dietary fiber above the 10% level depresses the growth of chickens. On the other hand Wilcke and Hammond (1940) and Davis and Briggs (1947, 1948) reported improved gains when cellulose was added to nutritionally adequate, fiber-free, purified chick diets. Further studies by Panda and Combs (1950), Hill and Dansky (1954), and Fisher and Weiss (1956) indicated that crude fiber level did not affect growth except as it affected the productive energy content of the ration; i.e., efficiency of utilization was not sacrificed when fiber was added, simultaneously with fat, to highenergy diets. The interrelationship between fat and fiber reported by Richardson et al. (1956, 1958) is a possible explanation for the disagreement of earlier observations as well as the effect observed…

Regression analysis of data from 2,815 fertile Coturnix eggs showed a very highly significant linear regression of hatchability on shape index. Estimates of surface to volume ratios from shape indices produced values fitting the regressed hatchability estimates very closely. Correlation between estimated values was + 0.998 (P

Four experiments were conducted to study the protein requirements of laying Coturnix hens. The results indicate that on a corn-soybean type diet, 20 percent protein was adequate for maximum reproductive performance and on higher energy diets containing 10 percent lard, 22 percent protein would support maximum egg production, egg weight, egg yield and efficiency of diet utilization. Results of these experiments show that a minimum daily intake of 4.71 gm. of protein is necessary for optimum response of Coturnix breeders.

INVESTIGATIONS demonstrating that there are specific breed differences in energy requirements and utilization attributed to genetic and physiological variation have been reviewed by Begin (1967). In this same report it was shown that, in a comparison of six breeds of chickens, the White Leghorn breed was significantly less efficient in its ability to utilize dietary protein and energy when the criterion of measurement was weight gain per unit of metabolizable energy and protein consumed. The two studies presented in this paper were undertaken to investigate further the relative ability of various breeds of chickens to utilize nitrogen and energy when measured as the tissue retention of these nutrients. Included in this investigation was a study of the effect of breed of chicken on the utilization of carbohydrates and fat as energy sources. Reports by Brambila and Hill (1966), Donaldson et al. (1957), Rand et al. (1958) and Renner (1964) have…

THE use of estrogenic compounds to improve the carcass qualities of young chickens is a rather widespread pactice in the poultry industry today. There is little information in the literature comparing gains, feed efficiency and carcass quality of chickens tested with various types of estrogenic compounds or caponized surgically. The effect of these compounds on birds of various ages has been studied by: Thayer et al. (1944), Lorenz (1945), Sturkie (1946), Issawi et al. (1956), and Moreng et al. (1956a,b). Lorenz (1953 Lorenz (1954) reviewed the literature on the use of estrogenic compounds in the poultry industry. Adams (1955) conducted an experiment in which comparisons of weight and carcass quality were made between surgical capons and diethylstilbestrol pelleted caponettes fed two types of diets. He reported that hormone-pelleted birds were superior to both surgical capons and untreated controls in both weight and carcass quality at 17 weeks of age. Romoser (1956) . . .

IT HAS been suggested by Wilson et al. (1961) that the Japanese quail (Coturnix coturnix japonica) is a suitable research animal for conducting pilot experiments for chickens and turkeys because of its close resemblance to these species. Although the Japanese quail has been used extensively in avian research, there have been few direct comparisons of this species with the more commonly used domestic breeds of chickens and turkeys. In view of the increased interest in the use of the Japanese quail in avian research, the experiments reported in this paper were designed to compare the relative abilities of this species and light breed chickens to metabolize and utilize energy from diets of different energy concentrations. EXPERIMENTAL METHODS Two experiments were conducted and, with the exception of the diets, the experimental procedures for both trials were as nearly alike as possible. Chicks of both species were hatched from eggs obtained from . . .

IN conducting nutritional studies, especially those concerned with energy metabolism, it is desirable to know the variation in nutrient utilization that can be attributed to the breed and sex of the birds used. The literature pertaining to differences in nutrient utilization, reviewed by Hutt (1964) and Sibbald and Slinger (1963b), indicates variations among breeds, strains and sexes in their nutritive requirements. These differences have been attributed to genetic and physiological variation. Specific breed differences in energy requirement and nutritive utilization have been reported by Shellenberger et al. (1960) and O’Neil et al. (1962). Sibbald and Slinger (1963b) and Slinger et al. (1964) have demonstrated that White Leghorn chicks metabolize more energy per unit of feed than do either White Plymouth Rock or commercial broiler cross chicks. A preliminary trial involving duplicate groups of male chicks of a New Hampshire X Silver Cornish cross and of a commercial incrossbred line, both …

THE increased interest in the energy nutrition of the chicken and progressive increase in the energy concentration of diets used for poultry has led to the present accepted practice of formulating poultry diets to contain a minimum level of crude fiber. There are, however, some experimental data which indicate that fiber may be of benefit in poultry diets. Penquite (1936), Sheehy (1939), Heuser et al. (1945), Fraps (1946), Carrick and Roberts (1947a, b), Scott et al. (1947) and Robertson et al. (1948) among others, have reported that both growth and feed utilization are impaired when diets containing fibrous ingredients are fed to chicks. This effect has been reported by Panda and Combs (1950), Hill and Dansky (1954), Peterson et al. (1954), Mraz et al. (1956) and Richardson et al. (1956) to be the results of the reduction in energy brought about by the energy diluting property of fibrous ingredients. While…

Muscle hexokinase was ascertained in the gastrocnemius muscles of 160 male chicks. Observations were made in four age groups and two diets. No differences in enzyme activity were observed which could be attributed to the feeding of either the high-carbohydrate or high-fat diet. Hexokinase activity declined significantly between 6 and 12 days of age in the chicks fed the respective diets.

Hatchability of Coturnix eggs in relation to age of breeders was observed in 17,693 fertile eggs. Observations were made over 12 lunar months in three age groups and two diets. All estimates of linear regression were negative and highly significant. Tests for curvilinearity were negative. Comparisons of linear regressions revealed no significant differences due to diet or age group. Adjusted means differed significantly, indicating possible general effects due to season and diet.

Previous work at this station has shown that in certain strains of New Hampshire chicks there exists a sex differential in growth response to antibiotic supplementation. Begin et al. (1953) observed that at 10 weeks of age the difference between the growth rate of male chicks fed an all vegetable-protein basal ration and the rate of those fed the basal ration supplemented with bacitracin was highly significant. The females on this same bacitracin supplemented ration and in the same pen failed to respond in a significant manner. Palafox and Rosenberg (1952) found a difference in sex response in New Hampshire chicks fed either a commercial aureomycin or terramycin feeding supplement. In their work the males in most instances exhibited a higher percentage growth response than did female chicks. The trial reported here was designed to study the growth response to bacitracin of birds whose sex had been modified by subcutaneous …

Addition of chlortetracycline to laying rations at levels of 200 and 500 grams per ton resulted in no significant changes in egg weight, shell thickness, pore count or pore diameter. The study was based on 630 eggs laid over 6 periods by 60 hens divided into 12 groups of 5 birds each. The groups were fed according to a statistical design of repeated latin squares balanced for estimation of residual effects.

FRAPS, Carlyle and Fudge (1940) are of the opinion that the metabolizable energy of chicken rations can be calculated with a high degree of accuracy from the digestible constituents of the diet and that there is a very close agreement between the metabolizable energy thus calculated and that determined by employing a bomb calorimeter. Axelsson and Eriksson (1951) and Titus (1955) are in agreement that the computation of metabolizable energy values from available digestibility data yields useful information. Hill and Anderson (1958) disagree with this and state that because of the limitations to which digestibility data are subjected, the computation of metabolizable energy values from available digestibility data is not completely satisfactory. The experimental work described here, using diets varying in energy content due to the step-wise addition of cellulose, made it possible to compare metabolizable energy values obtained by direct determination, using a bomb calorimeter, with the values computed…

Two experiments were conducted to investigate the relationship of energy source, age and glucose-6-phosphatase activity in the chick. In the first experiment liver glycogen and glucose-6-phosphatase were assayed in chicks of four age groups being fed either a high-fat or high-carbohydrate diet. It was observed that the feeding of the high-fat diet resulted in higher glucose-6-phosphatase activity and lower glycogen levels than did the feeding of the carbohydrate diet. Age was found to significantly influence enzyme activity. Both glucose-6-phosphatase and liver glycogen were found to be negatively correlated in the fat fed chicks. In the second experiment chicks were fed either a high-fat or high-carbohydrate diet for 28 days. Liver glucose-6-phosphatase activity was determined in representative samples of chicks from each group to establish basal levels. The diets were then reversed for a three-day period, after which the chicks were returned to their initial diets. Glucose-6-phosphatase was analysed at each step. Variation in enzyme activity in the chicks initially fed the high-fat diet could be attributed to differences in body weight. However, those chicks originally fed the carbohydrate diet did exhibit a true metabolic adaption when fed the high-fat diet.

Blood glucose levels and skeletal muscle glycogen concentrations were observed in 160 male chicks. Observations were made in four age groups and two diets. Carbohydrate diets resulted in higher blood glucose levels and glycogen concentrations than did fat diets. Age was found to significantly influence glycogen concentrations in both diets. The linear regression of skeletal glycogen on blood glucose levels was significant in carbohydrate fed chicks.

Two experiments were conducted to investigate the effects of varying levels of pantothenic acid on the efficiency of energy utilization and changes in body composition of the growing chick. The results indicate that a pantothenic acid deficiency does not interfere with the chick's ability to obtain metabolizable energy from the diet. The data do show that the efficiency of energy utilization and body composition were markedly affected when chicks were fed diets deficient in pantothenic acid. In both experiments, protein, fat and energy stores were significantly reduced when pantothenic acid-deficient diets were fed. Increased estimates of heat increment per gram of diet were observed when levels of pantothenic acid below the N.R.C. (1971) recommended level of 10 mg. per kg of diet were fed.

This report relates size to hatchability of Coturnix eggs. Two trials were run with breeders in their 8th month of production and one trial with breeders in their first month. After gathering from mass-mated pens consisting of 30 females and 10 males, the eggs were weighed individually and sorted into half gram classes. Pre-incubation storage was at approximately 14.0°C. Eggs were set at weekly intervals in Jamesway 252 trays modified with holders as described by Wilson et al. (1961). Holders were wrapped in two layers of cheesecloth to slow air movement. This practice stems from the results of Romanoff (1938) who found that Bobwhite quail eggs need slower air movement than pheasant eggs. Eggs were turned mechanically every two hours for 14 days, at which time they were trsansferred to hatching baskets. At the end of the hatch all unhatched eggs were opened, and infertile or broken eggs recorded. Throughout…