The effects of Zinc-Glycine and Zinc Sulphate supplement on broiler performance and immunity

This study was conducted to evaluate the effects of different dietary Zinc sources on performance, immune system and carcass quality of broiler chickens. Seven hundred and eighty five day-old broiler chickens (Arian strain) were randomly allocated to 35 experimental units (25 birds in each). This experiment was performed in a completely randomized design, as a 2×3 factorial with two sources (Zinc sulphate and Zinc-glycine) and three levels of dietary Zinc (40, 80 and 120 mg/kg) comparing with control group (without Zinc supplement). Effect of dietary treatments on body weight (day 7, 14, 21, 28, 35) was significant (P<0.05); however, no difference was observed between the treatments regarding to feed intake (P>0.05). Immune responses (antibody titer against SRBC, IgG, IgM, antibody titer against Newcastle virus), percentage of heterophile, lymphocyte and also heterophile to lymphocyte ratio were not influenced by the source and level of dietary Zinc. According to the results, mineral form of dietary zinc (ZnSO4) caused no significant difference in performance, carcass traits and immune responses of broilers in comparison with organic form (Zinc-glycine).