Broiler live performance response to dietary zinc source and the influence of zinc supplementation in broiler breeder diets

An experiment was conducted to examine the effects of Zn source and Zn concentration in caged broiler breeder hen diets on progeny performance. Eight dietary treatments were examined consisting of a 2 × 4 factorial arrangement (2-progeny diets and 4-diets provided to broiler breeder hens) with each treatment being represented by six replications. Progeny were provided diets supplemented with 140 mg Zn kg−1 from an inorganic source or a mixture of inorganic and organic sources. Slow-feathering, Cobb 500 broiler breeder hens were given one of four experimental diets containing 160 mg supplemental Zn kg−1 from Zn sulphate (ZnSO4), zinc-amino acid complex (ZnAA1), a combination of ZnSO4 and ZnAA, with each contributing one-half of the total supplemental Zn, or no supplemental Zn after 20 weeks of age (BASAL). Prior to 20 weeks, all hens were fed diets containing 160 mg supplemental Zn kg−1 from zinc-amino acid complex. Hatching eggs laid during 43 week were incubated and hatched. Three hundred and thirty-six resultant male chicks were given diets containing 140 mg supplemental Zn kg−1 from either ZnSO4 (140 mg Zn  kg−1) or ZnSO4 + ZnAA (ZnSO4, 100 mg Zn kg−1; ZnAA, 40 mg Zn kg−1) during a 17-d growth assay. The chicks originated from broiler breeder hens that were given a diet without supplemental Zn or diets supplemented with different sources of Zn. Providing supplemental Zn to hens in the form of ZnSO4 or ZnAA did not improve progeny performance. At 17 d, broilers fed diets supplemented with ZnSO4 + ZnAA had lower feed conversion (P < 0.001) and higher BW (P < 0.05) than broilers provided diets with added Zn from ZnSO4. These data indicate that broiler chick performance may be improved by replacing 40 mg Zn kg−1 diet from ZnSO4 with 40 mg Zn kg−1 from zinc-amino acid complex.