Peer review

Lysine caused a greater depression in growth of chicks fed a diet containing casein than a diet containing a combination of safflower meal, corn gluten meal and soybean meal. Glycine, in the presence of arginine, appeared to exhibit a synergistic effect in alleviating the growth depression induced by an excess of lysine. Similarly, glycine supplementation decreased nitrogen retention in a diet containing 1% but not 2% lysine. The increased need for arginine and glycine in the diet containing an excess of lysine was not due to an increase in the excretion of creatinine and uric acid. The data indicate an interaction among arginine, lysine and glycine in the nutrition of the chicken, and suggest that the presence of glycine limited the growth depression by lysine in the diet containing the plant proteins.

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