Comparison of Purified and Practical Diets for Reproduction in Japanese Quail

NUMEROUS experiments with laying hens conducted at this laboratory over the past several years have demonstrated that purified diets did not support reproductive performance equal to that obtained with practical diets. Both types of diets were formulated to contain adequate quantities of all known essential nutrients. Menge (1967) observed that rate of egg production, egg weight and hatchability of fertile eggs were significantly lower for hens fed a casein-gelatin-glucose diet compared with a corn-soybean diet. Substitution of isolated soy protein for casein and gelatin in the purified diet improved egg weight and hatchability but not rate of egg production. Young (1969) also noted that hens fed purified diets laid smaller eggs than hens fed a practical diet. The Japanese quail (Coturnix coturnix japonica) was selected to further investigate this problem. Wilson et al. (1961) described characteristics which make the Japanese quail a useful animal for research. Quail also eat less…