THE EFFECT OF DIFFERENT PER CENTS OF PROTEIN IN THE DIET

Abstract

Five groups of rats, I, II, III, IV and V, were fed throughout life on diets containing 10, 14, 18, 22 and 26% protein respectively. The greatest average maximal weight and the greatest average spontaneous activity were attained on the 14% protein diet and the lowest on the 26%. The highest % of fertility in both sexes was found in group II and the lowest in group V. The length of the reproductive span from greatest to least and also the average number of litters and young was in the order of groups II, I, III, IV and V. The mortality of the young while nursing was least in group II and greatest in V. Best growth of the young during lactation was attained on the higher % protein diets. The loss of weight of the mothers during lactation was greatest in group I and became less as the % of protein in the diet increased. The high % of protein was best for both mother and the growth of the young during the nursing period. The average life span from longest to shortest in both sexes was in the order of groups II, III, I, IV and V. The most frequent disturbance associated with death was lung trouble, more prevalent in [male][male] than in [female][fe]male]. No correlation between this ailment and the % of protein in the diet could be made. Lesion of the alimentary tract was more prevalent in [female][female] and greatest in group I. Tumors were more frequent in the [female][female] than in [male][male]. Only in groups I, II, and III did the [male][male] have tumors. The [female][female] of groups I, II and III had the greatest % of tumors. This suggests that high % protein diets are less conducive to tumor growth. Almost all the tumors in the 22 were associated with the mammary-glands and ovaries.