Evaluation of The Efficacy of Three Extenders on Boar Semen Quality after Liquid Storage

This study aimed to evaluate the efficacy of three commercial semen extenders, Modena, Zorlesco, and Vim on boar sperm quality during liquid storage in tropical Tanzania. Semen was collected from six healthy boars, representing three breeds (Large White, Duroc, and Dupi), and analyzed for motility, viability, acrosome integrity, morphology, and bacterial contamination. Ejaculates with a concentration of ≥40 million sperm/mL and ≥80% motility were selected for the study. Each ejaculate was split and extended with the three extenders, then stored at 17°C, with sperm quality assessed every 24 hours for up to 7 days. Modena demonstrated superior performance across all parameters, particularly in large white boars, maintaining sperm motility at 95.00±3.50% initially and 40.00± 5.67 % by 120 hours. It also preserved viability at 97.00± 0.65 % at 0 hours, decreasing to 37.50±8.67 % by 120 hours. Additionally, Modena was free from bacterial contamination across all breeds, significantly outperforming both Zorlesco and Vim. In contrast, Zorlesco exhibited the poorest performance, with sperm motility dropping from 92.00±4.30 % at 0 hours to 31.50±5.87 % by 120 hours in Large White. It also had the highest bacterial contamination, particularly with Staphylococcus spp. and Pseudomonas spp., and affected all breeds, with Dupi being the most contaminated. Vim showed moderate performance, particularly for Duroc and Dupi, where motility started at 85.00±13.67 % and 80.00±10.00 % but dropped to 20.00±2.67 % and 25.00±1.30 % respectively, by 120 hours. Microbial analysis revealed that Staphylococcus spp. is the predominant contaminant (42.86%), followed by Pseudomonas spp. (33.33%). These findings highlight the importance of selecting semen extenders tailored to breed-specific needs and challenging environmental conditions, particularly in tropical climates where bacterial contamination and temperature fluctuations pose significant challenges to semen preservation.