Effects of Specific Micronutrients on Semen Quality and Reproductive Outcomes in Peripubertal Sahiwal Bulls

Nutritional management with micronutrient supplementation impacts sexual behaviour, health, and semen production in bulls. This study aimed to evaluate the effect of micronutrients on seminal traits, hormonal profile, age at onset of puberty, and reproductive parameters in Sahiwal bull calves. Twenty-four Sahiwal bull calves were divided into four groups of six based on age and body weight. The Control Group received a basal diet (concentrate, green, and dry roughage). Group T1 received the basal diet plus a customised mineral mixture (Zn, Cu, Mn, Cr, and Co). Group T2 received the basal diet plus a customised vitamin mixture (vitamin A and vitamin E). Group T3 received the basal diet plus customised mineral (Zn, Cu, Mn, Cr, and Co) and vitamin (vitamin A and vitamin E) mixture. Seminal traits, hormonal profiles, age at puberty, and reproductive parameters were assessed. Micronutrient supplementation significantly improved seminal characteristics and hormone status in bull calves, and the age of puberty was significantly reduced. Testosterone levels in T3 and T1 were significantly higher after 90 days. Luteinising hormone levels were significantly higher during puberty in T3. Insulin-like growth factor levels remained unaltered. Scrotal biometry indicated a linear increase (p < 0.05) in scrotal circumference, paired testicular weight, and volume. Sexual behaviour indicators did not differ significantly between treatments. The age of puberty was significantly reduced in the T3 group. Micronutrient supplementation beyond basal levels enhances testicular growth, hormone status, and seminal quality in male calves, potentially improving reproductive performance. Micronutrient supplementation beyond the basal level significantly improves testicular growth, hormone status, seminal quality, and overall performance in peripubertal Sahiwal bulls.