NITROGEN SOURCE PRIMARILY SUPPLIED BY AMINO ACIDS AND THE EFFICACY FOR MAXIMAL GROWTH OF RATS

Abstract

The effect of osmotic pressure of diets on the food intake of young rats was investigated by comparing the nutritional effect of casein with the corresponding amino acid mixture at 3.2% nitrogen level. Changes in the osmolarity of diets due to the type of dietary carbohydrate had a little effect on food intake, whereas partial substitution of casein for amino acids resulted in significant increase in foodd intake. Weight gain and food intake of rats fed the 25% replaced amino acid diet were compared with those of rats fed the casein diet. Food intake was lower at 12.5% replacement than at 25% replacement. These observations suggest that a well-balanced amino acid mixture supported maximal growth of rats when 25% of the amino acid mixture was replaced with casein. This suggestion could be experimentally confirmed by using an amino acid mixture based on the amino acid composition of whole-egg protein.