The Effect of Supplementation of High Corn Diets on Rat Reproduction and Lactation

Abstract

The reproduction and lactation performances of rats fed diets composed principally of corn and soybean meal supplemented with known minerals and vitamins except vitamin B₁₂ have been found to be essentially normal. Resorptions, toxemia deaths, or excessive mortality during the first 48 hours after birth, during nursing, or after weaning have not been consistently observed. The weaning weights of the young from females fed supplements of natural and fermentation-by-product concentrates containing vitamin B₁₂, and perhaps other unknown factors, were consistently superior to those of young from females fed unsupplemented rations. Liver powder, concentrates of vitamin B₁₂, a fermentation by-product and an injectible antipernicious anemia extract have all been found to stimulate the growth of nursing rats. The factor involved in this stimulation appears to be soluble in 70% ethanol and less soluble in 95% ethanol.