Effect of Season and Age on Bacterial Load in Fresh Semen Ejaculates of Buffalo Bulls

Fresh semen of 10 Murrah buffalo bulls of two different age group viz. 4–5 years and 8–9 years having five bulls in each, were evaluated for total viable bacterial load during three different seasons (summer, rainy and winter). Mean bacterial load in fresh ejaculates of buffalo bulls (three ejaculates per bull in each season) was measured using standard plate count method and expressed as mean (± SEM) CFU per ml of semen. Non significant (P > 0.05) but visible differences of mean bacterial load in bubaline semen was recorded between seasons. Comparatively higher bacterial count in bubaline semen was observed during summer season (18000 ± 4667 CFU/ml) as compared to rainy (16000 ± 3055 CFU/ml) and winter season (12000±3266 CFU/ml). Likewise, nonsignificant (P>0.05) seasonal influence was recorded over bacterial load in semen from bulls of two different age groups. However, appreciable variation was noticed within seasons. During summer season, younger bulls (aged between 4–5 years) showed higher bacterial load (22000±8000 CFU/ml) as compared to older bulls (14000±5099 CFU/ml) and vice versa during winter season. Variations recorded during present study was due to significant variation (P<0.05) among individual bulls within and between seasons. Bacterial load in bubaline semen during summer season was negatively correlated with that during rainy (r = -0.296) and winter season (r = -0.19), however positive correlation (r = 0.423) was noticed between rainy and winter season. In conclusion, the changing seasons during the period of study produced nonsignificant effect on microbial quality of the spermatozoa in Murrah bulls.