The Nutritive Value of Animal Tissues in Growth, Reproduction and Lactation

Abstract

When alcohol-extracted liver furnished the protein of synthetic rations, all other recognized dietary requisites being supplied in uniform and presumably adequate amounts, growth of rats was normal at a protein level of 20 per cent; on a 15 per cent level growth was distinctly subnormal. In the second generation growth was below normal on both levels of protein. Lactation was deificient in the first generation and a failure in the second generation. Supplementary feeding of dried whole liver increased the growth rate of first and second generation animals; raw liver supplements enabled the females to lactate and led to the weaning of more vigorous young, to better growth in the two succeeding generations, and to partial success in lactation in the third generation. The reproductive mechanism was seriously deranged on these alcohol-extracted liver rations, as evidenced by irregular cycles and failure to mate at estrus.