ABSTRACT

This study was conducted to investigate the ameliorative effect of vitamin C and E dietary supplementation on growth performance, some hemato-biochemical parameters, antioxidant status and immune response in rabbits under the hot climatic condition in Egypt. Sixty weaned New Zealand White (NZW) rabbits were randomly assigned into four equal groups as follows; the control group was fed on the basal diet without any supplement, the other experimental groups were fed on basal diets supplemented either with 250 mg/kg of vitamin C or E and their combination for eight consecutive weeks. At the end of the experimental period feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR) were calculated and blood samples were collected. The results revealed that vitamins C and E supplementation significantly improved FI, FBW, and BWG, otherwise, FCR was significantly reduced. Dietary supplementation either with vitamin C or E significantly decreased the RBCs count, Hb concentration, PCV%, total leukocytic count, neutrophils and neutrophils/lymphocytes ratio compared to the control. A significant reduction in the serum total protein, albumin, cortisol, GSH and SOD was recorded in all supplemented groups. Meanwhile, dietary inclusion of vitamin C or E significantly enhanced serum glucose, T3 and NO levels as well as lysozyme and bactericidal activities compared to the control. These results indicate that dietary supplementation with antioxidant nutrients as vitamin C and E separately or in combination with rabbits was efficacious in alleviating heat stress negative effects on different examined parameters in rabbits.

Keywords:  Heat stress; Rabbits; Vitamin C and E; Endocrine changes; Antioxidant enzymes; Immune response.