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INCREASING quantities of supplemental fat are being used in poultry rations as a source of energy. As a result, numerous problems have been encountered under practical feeding conditions in handling mixed feeds which contain large amounts of fat. Maximum fat digestibility would require that a minimal amount of supplemental fat be used in a poultry ration to obtain the desired energy level. For this reason, it would be desirable to find ways to increase the digestibility of supplemental fat in poultry rations. It is known that certain emulsifying agents increase the digestibility of fat by both rats (Augur et al., 1947) and chicks (Fedde et al., 1960). Observations from the field and the results of feeding trials at the Oklahoma Agricultural Experiment Station indicate that when Yeast Culture3 was added to rations fed to growing turkeys there was an increased growth rate. It was postulated that the increased growth might…

THE effects of varied dietary levels of protein, energy, vitamins and minerals upon the performance of laying hens have been studied by many research workers including Berg et al. (1952), Ringrose et al. (1954), Heywang et al. (1955), Thornton et al. (1957), Adams et al. (1958), Hill et al. (1956), Anderson et al. (1957), Bolton (1958), Petersen et al. (1960), Thayer et al. (1956), Touchburn and Naber (1962), and Gleaves et al. (1961). The results obtained from these experiments have often been contradictory and confusing. For example, Berg et al. (1952), Thornton et al. (1957), and Adams et al. (1958) report that a dietary protein level of 13 percent is sufficient to maintain egg production, egg weight and body weight. On the other hand, Ringrose et al. (1954) and Heywang et al. (1955) state that 15 percent of dietary protein is adequate. Many possible explanations are given for such discrepancies . . .

MILO and corn are two of the principal grains available for use in the formulating of poultry diets. Semi-arid climatic conditions in many areas of the Southwest make it very difficult to raise corn, but large quantities of milo are produced. For this reason, the price of milo in these areas is substantially lower than the price of corn. This leads to the extensive use of large quantities of milo in poultry diets. A major problem encountered in this situation is one of determining, from a nutritional standpoint, how much milo can be used efficiently in these poultry diets. Published research data indicate that milo and corn give similar results in poultry diets when the differences in nutrient content of the two grains have been taken into consideration in the formulation of the diets. Hammond (1942) reported that either yellow milo or hegari is equal in value to white corn…

MANY interrelationships are encountered in studying amino acid requirements of animals. Because of this fact, methods which employ only the productive performance of an animal to determine dietary needs rapidly become inadequate when more than one or two amino acids are considered at a time. Any method which would aid in interpreting the amino acid interrelationships would be a tremendous step toward establishing a more efficient balance among the dietary amino acids for poultry. While a review of the literature on blood amino acid studies in other species provides limited supporting evidence, it seemed a reasonable possibility that with turkeys growing at the rate and with the efficiency of feed conversion obtained by Dunkelgod et al. (1961), the concentrations of amino acids in the blood might be correlated with dietary requirements. Richardson et al. (1953) added methionine and lysine separately and in combination to a diet deficient in both of…

RESEARCH data indicate that the daily feed consumption of laying hens depends primarily upon the levels of dietary protein and energy. Laying hens have the ability to compensate for low levels of dietary protein and energy by consuming more feed; and similarly, hens that are fed extremely high levels of protein and energy compensate by consuming less feed. This ability of the laying hen to regulate nutrient intake, by varying feed intake, has contributed greatly to the confusion over the exact percentages or proportions of nutrients required in laying hen diets. A comparison was made of the protein and energy intakes of laying hens at the Oklahoma Agricultural Experiment Station, when layer rations with graded levels of dietary energy and protein were fed. This comparison revealed that approximately 16 grams of protein and 300 kilocalories of energy were consumed per hen per day, regardless of the ration which was fed.…

IT HAS been demonstrated that within the bounds of present genetic potentials one pound of chicken broiler can be produced on 1.6 pounds of feed (Donaldson et al., 1957). Nutrient requirement data obtained under laboratory conditions have been used in the development of economically feasible chicken broiler diets for use under commercial production conditions. Commercial broiler producers using these practical diets have produced a pound of chicken broiler using 1.9 pounds of feed. A series of feeding trials with growing turkeys was initiated at Oklahoma State University in 1955 in order to determine the maximum efficiency with which growing turkeys could convert feed to turkey meat within present genetic limitations (Dunkelgod and Thayer, 1957, 1961). The results of this series of feeding trials indicated that poults of both sexes averaging 5.15 pounds in body weight could be produced in an eight-week growing period. Each pound of live turkey produced required…

VITAMIN requirement standards for laying hens are incomplete. A review of the literature reveals that very little experimental work has been done on vitamin requirements and vitamin interrelationships. Riboflavin and niacin are two of the vitamins which have received relatively little attention in requirement studies. Relatively little work has been published on the niacin requirements of laying hens, and the research data on riboflavin requirements are contradictory. Several attempts were made before 1950 to determine the quantitative requirements of laying hens for riboflavin. Davis et al. (1938) obtained normal production with a ration which contained 0.454 mg. per lb. (computed by them to contain 100 Cornell units per 100 gms.). Cravens et al. (1946) fed rations that varied from 1.3 to 1.9 mg. of riboflavin per lb. of finished ration. Based on data obtained in these trials, it was concluded that there were no significant differences in egg production between…

FEEDING standards for turkey poults are commonly based upon percentages or other proportional units of a prepared feed. While this method has obvious advantages, it does not take into account specific daily nutrient requirements. Furthermore, this method of determination does not offer an adequate basis for the consideration of nutrient interrelationships and nutrient balance. It is believed that these limitations have contributed greatly to the wide variation in nutrient allowances as currently recommended for growing turkeys. There appears to be a critical need to establish a more realistic basis for the determination of feeding standards. A need to determine nutritional requirements on a daily intake basis was first encountered in human nutrition. As early as 1921, Holt and Fales indicated that caloric requirement could be more adequately expressed as caloric intake per day per kilogram of body weight rather than other allowances. Cowgill (1928) emphasized the importance of daily nutrient …

SEMI-PURIFIED experimental turkey starter and grower diets which were developed at Oklahoma State University made it possible to produce a pound of market turkey on 2.2 pounds of feed (Thayer et al., 1961). The data from this feeding trial were used as a nutrient standard, and a linear programming program with an electronic computer was employed to formulate starter diets which contained practical feed ingredients. These practical type starter diets were formulated to be the equivalent in protein, amino acids and energy of the original semi-purified starter diet. Daily nutrient intake standards were developed for males and for females for each successive week of the growing period. These daily nutrient intake standards were utilized in modifying the starter diets into a series of grower diets. The practical type grower diets developed in this manner were fed to growing turkeys during an entire growing period from day-old to market weight. The…

DIETARY energy level is closely related to efficiency of feed utilization. Scott et al. (1947) demonstrated that chick diets which were high in energy promoted more rapid growth and more efficient feed conversion than did chick diets which contained relatively lower levels of energy. Scott, Heuser and Norris (1948) found that as the protein level of a poult starter diet was increased, it was necessary to increase the dietary energy level and the unidentified vitamin content of the diet if the most rapid growth and the most efficient feed conversion were to be obtained. As stabilized fats and greases became more readily available for use as fat supplements in poultry feeds, more intensive studies were undertaken to determine the interrelationship between energy and the protein levels in diets for chickens and turkeys, (Combs and Romoser, 1955; Leong et al., 1955; Matterson et al., 1955; Donaldson et al., 1955, 1956, 1957;…