The Arginine Requirement of Chicks Fed Purified and Corn-Soya Diets

PURIFIED diets containing 18 percent casein and 10 percent gelatin have been used extensively by various laboratories in chick nutrition studies. Until recently the adequacy of the amino-acids in this diet has not been seriously questioned. In an effort to further purify this diet for work on unidentified factors in this laboratory, the gelatin was omitted, the casein increased to 22 percent and the arginine content increased to 1.06 percent by the addition of 0.3 percent l-arginine HC1. This level of arginine is somewhat less than the requirement of 1.2 percent established for chick growth by Almquist (1947), Almquist and Merritt (1950) but slightly more than the 1.0 percent level proposed by Glista (1951) when the nitrogen balance technique was employed. The performance of the chicks on this modified diet was extremely poor and typical symptoms of arginine deficiency (ruffled feathers, ataxia and “goose-stepping”) were noted. It seemed desirable therefore …