Vol. 10, Issue 10, Part D (2025)

The study evaluated the relationship between serum testosterone concentration and morphometric traits in Ongole breeding bulls. Six breeding bulls were included in the study. Serum testosterone (nmol/L) was quantified via ELISA, while scrotal circumference, body girth and body length were measured; body weight was derived using Shaffer’s formula. Testosterone demonstrated statistically significant correlations with age (r=0.918) and scrotal circumference (r=0.915), while body girth (r=0.622) length (r=0.586) and calculated body weight (r=0.566) showed non-significant moderate trends. With regression analysis it was elucidated that age (R²=0.843) and scrotal circumference (R²=0.837) independently accounted for the variation in testosterone while scrotal circumference emerged to be a more practical selection trait. Inversely, scrotal circumference depends on the testosterone concentration, establishing bi-directional relationship. The findings suggest that scrotal circumference might be considered as a useful morphometric biomarker for testosterone, thereby for evaluating the endocrine and reproductive potential of breeding bulls.