Effects of Dietary Supplementations of Vitamin C, Organic Selenium, Betaine, and Pomegranate Peel on Alleviating the Effect of Heat Stress on Growing Rabbits

Abstract

Heat stress has become a global concern, one of the major environmental stressors, and causes substantial economic loss in the modern rabbit industry. Heat stress is caused by several factors such as high environmental temperature and humidity, causing a series of unfavorable changes in nutritional, physiological, and immunological functions, blood biochemical indexes, and antioxidant capacity. These factors negatively affect the productive performance and cecal fermentation and microbiota in rabbits. Thus, this study aimed to assess the potential use of feed additive strategies (e.g., vitamin C, organic selenium, betaine, and pomegranate peel) to mitigate heat stress on rabbits, and to evaluate rabbit performance, antioxidant status, and cecal fermentation and microbiota under heat stress. Rabbits fed diets supplemented with vitamin C, organic selenium, betaine, and pomegranate peel demonstrated significantly improved growth performance, nutrient digestion, concentrations of total and individual volatile fatty acids, and total cecal beneficial bacterial count. In contrast, there was a significant decrease in NH3-N concentration and pathogens’ counts (e.g., Enterococcus, coliforms, and E. coli) in the rabbit cecum. Blood biochemistry parameters and antioxidant capacity of rabbits supplemented with vitamin C, organic selenium, betaine, and pomegranate peel were observed to be improved in comparison to those in the control group. The results showed the significant impact that vitamin C, organic selenium, betaine, and pomegranate peel supplements play in alleviating heat stress and enhancing the positive effects on cecal fermentation and microbiota, antioxidant status, and rabbit performance. However, betaine supplementation had a superior positive impact on the nutritional and physiological profile of heat-stressed rabbits.