A Comparison of Fresh Semen Characteristics and Sperm Kinematics in Etawah Grade and Anglo-Nubian Bucks (Capra hircus)

Background: Artificial insemination (AI) programs in bucks depend on the availability of high-quality fresh semen to ensure reproductive efficiency and optimal genetic dissemination. Differences in breed characteristics may influence semen quality and sperm movement patterns, particularly in tropical conditions. Aims: This study aimed to compare the fresh semen characteristics and sperm kinematics parameters in Etawah Grade and Anglo-Nubian buck groups. Methods: Four bucks aged 3–4 years, comprising two Etawah Grade and two Anglo-Nubian bucks were used, with five ejaculates collected from each individual. Semen collection was performed twice a week using an artificial vagina under standardised management conditions. Fresh semen was evaluated macroscopically (volume, colour, consistency, and semen pH) and microscopically (motility, viability, abnormality, acrosome integrity, and sperm concentration). Sperm motility and kinematics were analysed using computer-assisted semen analysis (CASA) to obtain objective measurements of sperm movement patterns. Results: The breed had a significant impact on slow sperm motility, sperm concentration, acrosome integrity, and certain kinematic parameters, including ALH, BCF, HAC, LIN, and STR (p < 0.05). However, there were no significant differences between breeds in terms of total and progressive motility, as well as fast, circle, local, and immotile motility, viability, and the kinematic parameters VCL, VSL, VAP, DCL, DSL, and DAP (p > 0.05). Additionally, macroscopic semen characteristics and sperm abnormalities were similar across breeds. Conclusion: Breed-related differences were observed in specific semen quality and sperm kinematic parameters, notably sperm concentration, acrosome integrity, slow motility, and movement trajectory characteristics. In contrast, overall sperm motility was similar between Etawah Grade and Anglo-Nubian bucks.