Nutritional Value of Plant Materials V. Reproduction of Rats Fed Purified Rations Containing Soybean Protein

Abstract

Rats fed from weaning purified rations containing 24% protein in the form of a commercial soybean protein and dl-methionine produced young which had a very high mortality due to acute uremia of the newborn. The addition of liver extract or condensed fish solubles to the ration of the mothers greatly increased the rate of survival of the young. The survivors in the litters on the unsupplemented rations reproduced for two subsequent generations with essentially the same rate of mortality. Rats fed rations in which the commercial soybean protein had been extensively purified produced first litters which had a relatively low mortality. In the second litters the mortality of the young was much increased. The addition of liver extract to the ration containing the commercial soybean protein had no significant effect on the length of the estrous cycle or on the number of corpora lutea, implants, and resorptions, or the number or weight of young produced in the first pregnancy.