The effect of diet supplementation with vitamin C, corn oil on the performance of laying hens under heat stress

Abstract

This study was conducted at the poultry research station, Faculty of Agriculture, Al-Fatah University. Two experiments were carried out, each lasting for 8 weeks. In the first experiment, 126 Hisex brown laying hens of 53 weeks of age were randomly assigned to 9 treatments, receiving diets containing vitamin C (0, 500, or 1000 mg/kg) under three temperature levels (20°C, 20–40°C cyclic, or 38°C constant). In the second experiment, 123 Hisex brown laying hens of 26 weeks of age were assigned to 9 treatments, receiving diets containing corn oil (0, 3, or 8%) under the same three temperature regimes. Measurements included egg production, egg weight, shell thickness, weekly feed consumption, feed efficiency, and mortality rate. Results indicated that high temperatures adversely affected layer performance, with constant 38°C being the most detrimental. Vitamin C supplementation significantly (P<0.05P<0.05P<0.05) improved egg production at 20°C and 20–40°C cyclic, and enhanced shell thickness at 20–40°C cyclic and 38°C constant. Corn oil inclusion (3% or 8%) significantly improved egg production, egg weight, shell thickness, and feed efficiency across all temperatures, while significantly reducing mortality at 38°C constant.