Productive, biochemical and oxidative indices in hens with zinc and vitamin C supplementation in a hot environment

Heat stress is a critical factor that negatively affects poultry health and performances. Several nutritional strategies have been proposed to alleviate the adverse effects of heat stress, with vitamin and mineral supplementation being considered one of the most effective. This study aimed to investigate the impact of dietary supplementation of both zinc and vitamin C on various blood parameters –corticosterone, malondialdehyde (MDA), ferric reducing ability of plasma (FRAP), total cholesterol and total protein, as well as production performance indicators, including egg-laying capacity and live body weight. The research was conducted on laying hens housed under a semi-open rearing system within a hot environment. A total of 400 DeKalb Brown laying hens were divided into two groups: a control group and an experimental group, each consisting of 180 females and 20 males. The experimental group received a diet supplemented with 35 mg zinc oxide and 250 mg vitamin C per kilogram feed. In a high-temperature environment (average ambient temperature of 32.6 °C), hens supplemented with zinc and vitamin C showed significantly lower levels of corticosterone (P<0.001), MDA (P<0.001), oxidative stress index (OSI) (P<0.05) and cholesterol (P<0.01), compared to the control group. At the same time, the experimental group showed a significantly greater egg-laying capacity (P<0.001) and increased live body weight (P<0.01) compared to the control birds. Zinc and vitamin C may therefore act synergistically towards both heat and oxidative stress reduction, with beneficial effects on egg-laying capacity and body weight maintainance of hens in a hot environment.