The Effect of <i>in ovo</i> Supplementation of Nano Zinc Oxide Particles on Hatchability and Post-Hatch Immune System of Broiler Chicken

Abstract

The aim of this study was to evaluate the effects of <em>in ovo</em> injection of zinc oxide nanoparticles on the hatchability, production performance and immune responses of broilers. A total of 192 fertile eggs obtained from a Ross 308 broiler breeder flock were used. The eggs were divided into 4 experimental groups including a positive control group with normal saline injection, and injection of 50, 75 and 100 ppm nano-ZnO on the first day of incubation period in the air cell and were placed in the incubator. The hatched chicks were allocated to a completely randomized design with 4 treatments and 4 replicates for a 42-day experiment. <em>In ovo</em> injection of nano-ZnO increased hatchability of eggs compared to the control group (p < 0.05). The daily feed intake during the starter phase significantly increased in the birds in 50 and 75 ppm nano-ZnO groups (p < 0.05). At the grower phase in rearing period the growth rate and feed intake of all the nano-ZnO injected groups were higher than the control group (p < 0.05). There was no significant difference in the feed conversion ratio between different treatment groups (P>0.05). The results of antibody titer against the influenza virus at 10 days of age did not differ between the experimental treatments (P>0.05). The heterophil, lymphocytes, monocytes and hematocrit number in the blood of broiler chickens at 10 days of age did not show any significant difference (P>0.05). The results of the present study suggest that <em>in ovo</em> injection of nano ZnO particles had positive effects on early embryo mortality rate, total white blood cells, however the performance traits of the hatched chicks were not significantly affected through <em>in ovo</em> injection of nano ZnO particles.