Effect of Dietary Methionine and Arginine on the Excretion of Nitrogen in the Cocks Fed a Protein-free Diet

Abstract

The nitrogen sparing action of methionine and arginine supplementations to a protein-free diet were studied with colostomized adult cocks.Body weight loss of the cocks fed a protein-free diet was alleviated with methionine or arginine supplementation, but neither effect was significant. Faecal nitrogen showed comparable values and urinary nitrogen of the cocks fed the methionine supplemented diet was the lowest of the 3 groups. The nitrogen balance were, in the order of increasing, methionine supplemented, arginine supplemented and protein-free groups.Each of the major urinary nitrogenous compounds of cocks fed the methionine supplemented diet showed lower values than the corresponding values for the cocks fed a protein-free diet. From the result of faecal nitrogen and faecal amino acid analysis, there was no evidence that the re-utilization of endogenous nitrogen of the birds fed a protein-free diet was enhanced by the addition of methionine or arginine.