The combined effect of moderate excess dietary vitamin E and marginal amounts of dietary cholecalciferol on the performance and tibia bone ash of young male broiler chicks was evaluated. Vitamin E (alpha-tocopheryl acetate) and cholecalciferol were added to a commercial diet not already supplemented with these vitamins, at concentrations of 0 and 150 mg/kg, and 1.875, 5 and 25 micrograms/kg, respectively, and fed to chicks for 23 d. 2. Vitamin E concentration and its combinations with cholecalciferol did not significantly (P > 0.05) affect food intake, weight gain, food efficiency and bone ash. These variables were significantly (P < 0.001) lower in chicks fed on the diets supplemented with 1.875 micrograms cholecalciferol/kg compared with the values observed with the 2 other concentrations of this vitamin. There were no differences in the effects of 5 and 25 micrograms cholecalciferol/kg diet on the above variables. 3. It was concluded that vitamin E, at a concentration of 150 mg/kg diet, did not aggravate a mild cholecalciferol deficiency.
