Effect on Hatchability of Fish Meal Fed to Hens Deficient in the Unidentified Hatchability Factor

VARIOUS workers have shown that fish meal and other animal products contain an unidentified hatchability factor(s) that is absent in plant products. Lampman and associates (1944) have shown that rations supplemented only with plant proteins, such as soybean oil meal, resulted in reduced hatchability. Rubin, et al., (1946) showed that an unidentified chick growth factor present in cow manure was also found in the droppings of hens. Kennard and co-workers (1948) reported experimental work which indicated that the unidentified hatchability factor was present in hen feces, especially when a built-up litter program was used. Since McGinnis and co-workers (1947) presented evidence that the synthesis of this factor occurs after feces have been voided, it would appear that it was obtained by the hens through coprophagy. Rubin, Groschke, and Bird (1947) reported that an acid precipitate of a water extract of cow manure was highly potent in the hatchability factor required . . .