Sulfur Amino Acid and Methyl Donor Status of Corn-Soy Diets Fed to Starting Broiler Chicks and Turkey Poults1

ABSTRACT Experiments were conducted to determine the effects of supplementing corn-soy-bean meal-white grease diets with sulfur amino acids and methyl group donors for starting broiler-strain chicks. The diets (23 % protein and 3200 kcal ME/kg) were fed to quadruplicate lots of chicks in battery brooders. The diets were calculated to contain.37 % methionine,.37 % cystine, and 1499 mg/kg choline. Chemical and microbiological assays yielded values of.32 % and.42 % for methionine and cystine content respectively. Results of 5 chick experiments showed that supplementing this diet with.23 % DL-methionine significantly (P<.05) improved 3 week-gain (375 vs. 415 g) and feed/gain (1.54 vs. 1.47) over that obtained with the basal diet. When L-cystine and 2(CaSO„)-HaO failed to give a significant (P>.05) response, compounds capable of donating methyl groups were fed. Significant (P<.05) re-sponses in gain (404 and 420) and feed/gain (1.48 and 1.51) over the basal were obtained with cho-line and betaine. These responses were not significantly (P>.05) different from that obtained with methionine. Serine and sodium formate failed to give consistent responses. Using a poult diet of 28 % protein and 2800 kcal ME/kg, a significant (P<.05) response to DL-methionine was again observed, with intermediate responses to betaine, choline, and serine. It is concluded that (within the limits of the experimental model) corn-soy type diets contain an ade-quate amount of total sulfur amino acid for chicks, but not poults, when sufficient choline or be-taine are provided