Iodine Supplementation Improved Antioxidant Status, Hormonal Status, Sexual Behavior, and Semen Production Performance of Bos indicus Bulls Under Tropical Climatic Condition.

Iodine is anessential micronutrient that plays a crucial role in male reproduction (sexual behavior and semen production performance) by modulating thyroid function and the antioxidant status of the animal. Nonetheless, in Bos indicus bulls, a thorough evaluation of the effects of dietary iodine supplementation on antioxidant status, seminal quality parameters, and its interaction with other minerals is not documented. Twelve Bos indicus (Sahiwal) bulls were distributed into three groups (n = 4 in each group) viz. T1 (control), T2, and T3 and fed diets containing 0.250, 0.375, and 0.500 ppm iodine/ kg dry matter intake, corresponding to 0%, 50%, and 100% higher than ICAR (2013) recommendations, respectively. The experimental feeding was carried out for 60 days and the effects on nutrient utilization, hormonal and antioxidant status, and sperm function tests were investigated. Results revealed that body weight, dry matter intake, and nutrient digestibility remained unaffected by dietary supplementation of iodine. Testosterone and thyroxine hormone concentrations were improved (p<0.05) in T2 and T3 groups. Blood and seminal iodine content were also higher (p<0.05) in both the supplemented groups (T2 and T3). Sperm functions viz. viability, physical membrane integrity, acrosomal integrity, motility, and mitochondrial membrane potential were improved (p<0.05) due to iodine supplementation. Furthermore, lipid peroxidation and membrane scrambling in spermatozoa were reduced (p<0.05) in T2 and T3 groups. Blood antioxidant status (total antioxidant activity and GPx levels) was improved (p<0.05) in T2 and T3. Sexual behavior was also improved (p<0.05) in iodine-supplemented groups. Hence, it can be concluded that iodine supplementation at the dose rate of 0.500 ppm in the Bos indicus bull diet is beneficial in improving hormonal status, antioxidant status, and semen quality.