The Effect of Different Dietary Zinc Sources on the Egg Production, Sex Hormone Concentration and Blood Zinc Serum of Broiler Breeders

This study was conducted to evaluate the effect of different dietary zinc sources on the egg production, sex hormone concentration and blood zinc serum of broiler breeders of Ross strain 308. Two hundred birds in 4 treatments and 5 replications and 10 birds in each experimental unit at the age of 45 weeks were tested in a completely randomized design. Experimental groups included: 1-Birds fed the basal diet without any addition of zinc, 2- Birds fed diet supplemented by 110 mg Zn (sulfate)/kg of diet, 3- Birds fed diet supplemented by 110 mg Zn (organic)/kg of diet and 4-Birds fed diet supplemented with 110 mg Zn (hydroxide)/kg of diet. In this study, egg production traits as well as zinc serum, estrogen and progesterone concentrations of experimental birds were measured at 32 and 45 weeks of the experiment. The results of egg production showed that there was a significant difference between experimental treatments (p <0.05). The highest and lowest number of eggs produced were in treatment containing organic zinc and control treatment, respectively. Zinc serum concentrations at 32 and 45 weeks of the experiment were significantly different between experimental treatments (p <0.05). The highest and lowest zinc serum concentrations were in treatment containing organic zinc and control treatment, respectively. No significant difference was observed in serum concentrations in the blood of broiler breeders. The results of serum estrogen and progesterone concentrations showed that there was a significant difference between experimental treatments (p <0.05). The highest and lowest concentrations of sex hormones were in the treatment containing organic zinc and the control treatment, respectively. The overall results of the study showed that the use of organic zinc supplementation in broiler breeders’ diet significantly increased zinc serum levels as well as sex hormones. Also, organic zinc supplementation significantly improved egg production among the studied birds.