EFFECT OF SUPPLEMENTING A RICE-SOYBEAN DIET WITH METHIONINE ON GROWTH OF RATS / 营养学报

ABSTRACT

Microbiological assay of the essential amino acids was carried out on a 10% protein diet containing 80% rice and 6% soybean meal. The most limitng essential amino acid according to the value recommended by Rose was found to be methionine(0.09%), the second was lysine(0.29%), and the third histidine(0.23%).The animal experiment consisted of 2 parts. In the first the effect of adding 0.3, 0.6, 0.9 and 1.8g% of DL-methionine to the basal diet was observed upon the growth of weanling albino rats for a two-week period.Results revealed that supplementation of methionine at all level tended to dep- ress growth of rats, especially at the 1.8% level, i.e. an average of 7g gain per two weeks compared with 29g of control group when no methionine was added.In the second part the effect of supplementing lysine or histidine to the level recommended by Rose, or adding pyridoxine was studied on the growth depression, caused by methionine excess in the diet of rats. Lysine improved food consumption and weight gain, showing an average of 23.5g for the two-week period, while it was 17.5g on the methionine excess diet. However, it did not reach the 35g of the basal diet group Both histidine and pyridoxine did not have any effect, the liver weight changes of rats were related to their body weight changes. No significant differences in liver nitrogen, liver water content and concentration of hemoglobin among the different groups were found.