Dietary Antioxidants at Supranutritional Doses Improve Oxidative Status and Reduce the Negative Effects of Heat Stress in Sheep

Abstract

The present study was undertaken to investigate the impact of heat (thermal) stress and dietary antioxidant supplementation on the oxidative and physiological status of sheep. Twenty-four Merino × Poll Dorset crossbred ewes were housed in 1 of 2 climatic chambers (thermoneutral or heat stress) and offered either a control (10 IU vitamin E/kg DM and 0.24 mg Se/kg DM) or high antioxidant (100 IU vitamin E/kg DM and 1.20 mg Se/kg DM) diet. The sheep were exposed to 2 thermal (temperature) treatments (thermoneutral [TN]: 18–21°C and 26–30% relative humidity; and heat stress [HS]: 28–40°C and 40–50% relative humidity) for 2 wk in a single reversal design. After 1 wk of dietary treatment, animals ..