Objective: The potentiality of extra virgin olive oil (EVOO), betaine (BET) and ginger (GIN), as a natural antioxidant, to reduce negative effects of heat stress on physiological responses, antioxidant capacity, semen quality and fertility of bucks under heat stress were investigated.Methods: Forty adult APRI line rabbit bucks were distributed randomly into four experimental treatments of ten rabbits each. The first treatment was fed the commercial pellet diet (CPD) without supplementation and served as a control. The other three treatments were fed CPD supplemented with EVOO (300 mg), BET (1000 mg) and GIN (200 mg) per kg diet for 3 consecutive months during the summer season.Results: Supplementation of EVOO, BET or GIN improved (p< 0.05) the sexual desire, progressive motility, vitality, intact acrosome and membrane integrity, sperm cell concentration, sperm outputs and fertility. Seminal plasma total proteins, globulin, total antioxidant capacity, glutathione and glutathione S-transferase, and initial fructose increased (p< 0.05), while total lipids, aspartate and alanine aminotransferases and malondialdehyde decreased (p< 0.05) compared with the control. In comparing the natural antioxidants treatments, GIN evoked the largest improvement.
Conclusion:The inclusion of GIN (200 mg/kg diet) as a useful agent for improving the sexual desire, semen quality and oxidative stress of bucks. This may be a beneficial supplement for the management of rabbit bucks used in natural mating or artificial insemination.