Live Performance and Immune Responses of Straight-Run Broilers: Influences of Zinc Source in Broiler Breeder Hen and Progeny Diets and Ambient Temperature During the Broiler Production Period

Abstract

Supplemental zinc in broiler diets has been reported to be more available to the chick when provided as a zinc-amino acid complex rather than an inorganic source. Previous work with broiler breeder and turkey hens has indicated that supplementing diets with zinc-amino acid complexes enhances immune status and livability of progeny. This study examined the effects of supplemental dietary zinc source [ZnSO4 or Availa Zn 100 zinc-amino acid complex (ZnAA)] provided to broiler breeder hens and their progeny on live performance and immune status of broilers. Broiler breeder and progeny diets were supplemented with 160 and 140 ppm zinc, respectively. In addition to the dietary treatments, the broilers were subjected to either optimum or suboptimum temperatures during the first weeks of production. Supplementing broiler breeder hen and progeny diets with ZnAA and ZnAA + ZnSO4, respectively, improved cumulative feed conversion (FC) of broilers. Providing diets supplemented with ZnSO4 to hens or exposing broilers to optimum temperatures enhanced humoral immune response of progeny. Subjecting broilers to suboptimum brooding temperatures increased feed intake, but a higher incidence of mortality occurred primarily encompassing the first week of the growout. These data indicate that brooding temperature affected broiler performance, whereas the response to dietary zinc source was less pronounced.