Influence of Dietary Protein and Methionine Levels on the Requirement for Choline by Chickens

Abstract
The dietary protein and methionine levels were found to affect the quantitative requirement of young chicks for choline. Over three times as much choline was required for maximum growth of chicks when they were fed a diet containing 64% protein than when they were fed 13% protein. A high protein diet markedly increased the incidence of perosis in chicks fed a choline-deficient diet. When diets containing 13% protein were supplemented with 0.84% methionine, the choline required for prevention of perosis and maximum growth rate was 800 mg/kg of diet compared with 300 mg/kg of diet when the basal diet was fed without the high level of methionine. The results of these studies show that the choline requirement of chicks is elevated by high dietary levels of methionine and protein. The metabolic alterations responsible for such changes in requirement were not determined.