The Effect of Several Protein Supplements on Hatchability When Fed to Hens in Open Pens and Batteries

MANY investigators have shown that various ingredients are essential in the breeder diet to promote hatchability and to produce strong viable chicks. It has been demonstrated that plant proteins are deficient in an unidentified factor, or factors, essential for hatchability, whereas animal and marine protein concentrates are sources of this essential nutrient. Various workers have found this factor in fish meals, meat meal, milk products, liver, and condensed fish solubles. Bethke and associates (1946, 1947) have shown that the factor essential for hatchability was not choline, methionine, riboflavin, pantothenic acid, niacin, pyridoxine, folic acid, or biotin. Whitson and associates, 1946, revealed that the addition of cow manure, dried at 80° C., to as oybean oil meal supplemented diet improved hatchability, especially during the winter and early spring months. Rubin and Bird, 1946, found that the growth factor for chicks present in cow manure, as reported by Hammond (1942), was not . . .