Zinc and vitamin E in diets for broilers reared under heat stress

Abstract

The objective of this research was to evaluate the use of zinc and vitamin E in diets for broilers kept in reused litter, between 1-21 days of age, over performance, lymphoid organs, heart and digestive organs weight. Seven hundred chicks distributed in a completely randomized design in a factorial scheme 2x3+1, with two levels of zinc (0.0 and 120 mg/kg diet) associated with three levels of vitamin E (0.0, 300 and 600mg/kg diet), a control diet and five replications, were created in sheds covered masonry ceramic tiles and concrete floor . In the period of 1-21 days the weight gain is greater, without supplementation of zinc and vitamin E, when birds are kept on reused litter compared to those kept on new litter. The isolated supplementation of 300mg vitamin E/kg and the combination of 120mg zinc/kg with 600mg vitamin E/kg gives greater weight gain for broilers raised on reused litter compared to birds fed in a control diet kept in new litter. We conclude that the reviews levels of zinc and vitamin E do not improve feed intake, weight gain, feed conversion, the production viability and productive efficiency rate of broilers kept in re-used litter of 1 to 21 days of age. The intestine weight increases and the spleen’s decreases as vitamin E is supplemented in the diets of these animals.