Minimum Levels of Animal Protein for Reproduction

The reports of Christiansen, Halpin, and Hart (1940) and of the Cornell workers (quoted by Almquist, 1943) indicate that good production may be obtained when soybean oil meal is the sole protein supplement in a laying ration. However, the reports of Byerly, Titus, and Ellis (1933a) & (1933b); Byerly, Titus, Ellis, and Nestler (1937); Christiansen, et al. (1940); and Wilgus and Gassner (1941) indicate that such rations will not support maximum hatchability. The data of the latter workers showed that 5 percent of meat and bone scrap in an all-mash ration including soybean oil meal enabled normal hatchability while the milk protein, casein, did not. The present necessity for conserving animal protein sources and using all the soybean oil meal possible led to the initiation of studies to ascertain the minimum amount of meat and bone scrap protein required in breeding rations. In the fall of 1942 three pens of . . .