Effect of Season on Bacterial Load in Semen of Different Breeds of Cattle

Fresh semen ejaculates collected from 56 cow bulls of different breed during three different seasons (summer, rainy and winter of the year) were subjected to bacteriological examination. Total viable bacterial count of fresh semen was determined using standard plate count method and result expressed as mean (±SEM) CFU/ml of semen. Significantly (P<0.05) higher bacterial load (33571 ± 3842 CFU/ml) in bovine semen was reported during rainy season as compared to summer and winter season. During rainy season, Gir semen showed significantly (P<0.05) higher bacterial count (37500 ± 7500 CFU/ml). During summer season, bacterial count was significantly (P<0.001) higher in semen of exotic bulls (37143 ± 3595 CFU/ml) followed by crossbred (32000 ± 5333 CFU/ml) and indigenous bulls (19359 ± 1875 CFU/ml), whereas non significant variation were noticed during rainy and winter season. Among breeds, significantly (P<0.005) higher count was reported in Jersey and HF cross during summer; and in Jersey and Gir during rainy season, however; Tharparkar and Red Sindhi bulls yielded significantly (P<0.005) lower bacterial load in their semen as compared to other breeds during whole seasons of the year. It could be concluded from the results of the present study that season had significant effect on bacterial load in semen of different breeds of cow bulls.