Effect of species, breed, and age on bacterial load in bovine and bubaline semen

Aim: The present study was conducted to investigate the effect of species, breed and age on bacterial load in fresh and frozen semen of Cattle and Buffalo bull. Materials and Methods: Present study covered 56 cow and 10 buffalo bulls stationed at Central Semen Station Anjora, Durg (Chhattisgarh). Impact of breeds on bacterial load in semen was assessed using six breeds of cattle viz. Sahiwal, Gir, Red Sindhi, Tharparkar, Jersey and Holstein Friesian (HF) cross. Cow bulls were categorized into four different groups based on their age (< 4 years, 4-5 years, 5-6 years and > 6 years) to study variation among age groups. Bacterial load was measured in fresh and frozen semen samples from these bulls using the standard plate count (SPC) method and count was expressed as colony forming unit (CFU) per ml of semen. Results: Higher bacterial load was reported in fresh (2.36 x 104 +/- 1943 CFU/ml) and frozen (1.00 x 10 +/- 90 CFU/ml) semen of cow bulls as compared to buffalo bulls (1.95 x 10(4) +/- 2882 and 7.75 x 10(2) +/- 160 CFU/ml in fresh and frozen semen, respectively). Jersey bull showed significantly higher bacterial count (p < 0.05) both in fresh (4.07 x 10(4) +/- 13927 CFU/ml) and frozen (1.92 x 10(3) +/- 178 CFU/ml) semen followed by HF cross, Sahiwal, Gir, Red Sindhi and Tharparkar bull. Bulls aged < 4 years and more than 6 years yielded increased bacterial load in their semen. Although a minor variation was reported between species and among age groups, no significant differences were measured. Conclusion: Bacterial load in semen did not differ significantly between species and age groups; however significant variation was reported among different breeds. Bulls of Jersey breed showed significantly higher bacterial load in semen as compared to the crossbred and indigenous bull.