Abstract
The relationship between nitrogen levels of the diets and their nutritional efficiencies were observed on feeding experiment on rats.
The test diets were composed of milk casein to which were added 1% L-cystine, wheat starch, granulated sugar, vegetable oil, vitamins and minerals. Six test diets having 1.6, 1.4, 1.2, 1.0, 0.8, and 0.6% nitrogen level were prepared. Young rats were fed on these test diets for 30 days, and growth of rats, nitrogen efficiency and nitrogen balance were observed. When fed on diets of over 1% nitrogen almost normal growth was kept in rats, while nitrogen efficiency of the diet of 0.8% nitrogen was higher than that of over 1% nitrogen.
According to these results, the authors considered that about 1% nitrogen level of diet was the lower limit for normal rat's growth and high nitrogen efficiency of diet was kept on this level.
