The Effect of Energy and Protein Levels on Egg Production, Feed Efficiency and Some Lipid Constituents of Blood and Liver of Caged Layers

THE successful utilization of animal and vegetable fats in the diet of growing chickens has prompted studies as to the possible use of these fats in the diet of the laying hen. Several workers have reported increased egg production and improved feed efficiency through the use of high energy (low fiber) type diets (Quisenberry et al., 1949; Skinner et al., 1951). The amount of protein required in such high energy diets has not been clearly established. Heuser (1941) reported that the protein required for optimum production was at least 15%. Hill and Anderson (1955) reported that the protein requirement of White Leghorn hens (average mature body weight five pounds) was 15% in a ration containing approximately 960 Calories of productive energy per pound (Calorie-protein ratio1 of 64/1). Other workers have indicated that a higher level of protein (18%) may be required (Reid et al., 1951; Quisenberry, 1955; and Williams, 1951).