Abstract
In order to know the influence of age on the supplement of polished rice with lysine and threonine weaning male rats were fed on a 90% rice diet supplemented with or without 0.4% L-lysien hydrochloride and 0.24% DL-threonine (diets 2 and 1) from weaning to 15-week-old. Rats fed on diet 2 showed higher growth rate, higher ratio of retained nitrogen to absorbed nitrogen, and higher ratio of urinary allantoin to urinary urea than those of rats fed on diet 1 throughout the periods.
When rats of about 20-week-old were fed on diets 1 and 2, the ratio of retained nitrogen to absorbed nitrogen, biological value, true digestibility and net protein utilization did not differ among rats of both dietary groups.
By the depletion-repletion technique, increase in body weights of adult rats fed on an 85% rice diet supplemented with 0.2% L-lysien hydrochloride and 0.24% DL-threonine was found significantly greater than those of adult rats fed on an 85% rice diet.
