Niacin requirement of turkey poults fed a corn-soybean meal diet from 1 to 21 days of age.

Nicholas Large White turkey poults were used in three experiments to reevaluate the niacin requirement between 1 and 21 days of age. In Experiment 1, 384 turkey poults were assigned to six dietary treatments, 0, 5.5, 11.0, 22.0, 44.0, and 88 mg of supplemental niacin/kg basal diet. Eight replicates of eight birds/pen (equal numbers of male and female poults) were used per diet. In Experiment 2, 320 birds were assigned to the same dietary treatment as in the first experiment except for the 44.0-mg niacin treatment. In Experiment 3, 288 turkey poults were assigned to six dietary treatments, 0, 6, 12, 18, 24, and 30 mg of supplemental niacin/kg of feed. The basal diet with no added niacin was a corn-soybean meal diet calculated to contain 28.5% crude protein. The analyses of tryptophan were .35, .35, and .34%, and of niacin were 26, 26, and 23 mg/kg in the basal diets of Experiments 1, 2, and 3, respectively. Using the broken-line technique to determine the minimum niacin requirement for maximum body growth at 21 days of age, and taking into consideration the dietary supplemental niacin needed to prevent leg abnormalities, it was estimated that the minimum dietary niacin requirement for turkey poults from Day 1 to 21 days of age was 44 mg/kg of feed. Feed intake was maximized, and feed conversion was improved in a parallel fashion to growth. The incidence of leg disorders decreased in number and severity as supplemental niacin was increased in the diet.