Effect of niacin supplementation of a corn-soybean meal diet on performance of turkey breeder hens.

Two trials were conducted to determine the need for niacin supplementation of Nicholas Large White Turkey hens fed a corn-soybean meal diet from 224 to 336 days of age. Analysis of the corn and soybean meal indicated the niacin contribution to be 23.6 mg/kg diet. No supplemental niacin was required for maximum egg production, fertility, or hatchability. However, body and egg weights were significantly increased when 8.4 and 16.7 mg niacin were added per kilogram of diet, respectively. These data indicate that the turkey hen does not require more than 23.6 mg niacin/kg of a corn-soybean meal diet for egg production, but 40.3 mg/kg was required for maximum egg weight in the presence of .17% tryptophan (analyzed in corn and soybean meal).