Effects of In Ovo Injection of Zinc or Diet Supplementation of Zinc on Performance, Serum Biochemical Profiles, and Meat Quality in Broilers

SIMPLE SUMMARY: Zinc (Zn) is known as an essential trace mineral that plays a key role in metabolic processes such as synthesis, stability, and catalytic activity of many proteins in broilers. In ovo technology provides an alternative for delivering nutrient compounds to the embryo prior to hatching by injecting small amounts of material into a broiler egg during hatching. In this study, the in ovo injection of Zn and dietary supplementation of Zn were evaluated on their effects on growth performance, serum biochemical profiles, and meat quality in broilers. In ovo injection and Zn supplementation (i.e., 200 mg/kg) increased (p < 0.05) body weight and immunoglobulin G (IgG) compared to broilers fed with the control diet. In ovo injection group decreased (p < 0.05) feed conversion ratios compared to broilers fed with the no injection group. Our results indicated that broilers fed with a diet supplemented with 200 mg/kg of Zn could ameliorate growth performance, immune responses, and increase the unsaturated fatty acids of breast meat. The findings of this result highlighted that the diet supplemented with Zn has the effect to improve performance, blood immune response, and fatty acid profile of breast meat. ABSTRACT: This study investigated the main effects of the in ovo injection of inorganic zinc (Zn) or diet supplementation of Zn on performance, serum biochemical profiles, and breast meat quality in broilers. A total of 480 one-day-old broilers (Ross 308) were randomly divided into four groups: the control (Con, noninjected and basal diet), in ovo (injected 60 mg Zn/egg at 18 embryonic days of incubation and basal diet), Zn100 (noninjected and basal diet with Zn (100 mg/kg) for 35 days), and Zn200 (noninjected and basal diet with Zn (200 mg/kg) for 35 days) groups. The dietary supplementation of Zn increased feed intake (2860.42–2861.08 g), weight (1975.06–1985.25 g), and weight gain (1936.36–1946.53 g) compared to Con (2785.74, 1891.38, and 1852.62 g, respectively) after five weeks of age. No significant difference was found in biochemical parameters and leukocyte and erythrocyte levels in the blood among the four different groups. In ovo injected or supplemental Zn (100 and 200 mg/kg) increased IgG in the blood of broilers. Zn200 increased polyunsaturated fatty acids, and saturated fatty acid contents were reduced in breast meat compared with Con. In conclusion, Zn supplementation at 200 mg/kg could improve the weight, feed intake, blood immune response, and fatty acid profile of breast meat.