Conception rates of cows inseminated with frozen semen of Rural Development Academy, Bogura, Bangladesh

Background: The first service conception rate (FSCR) is an important parameter for any artificial insemination (AI) programme. The present study was conducted to determine the FSCR and its influencing factors in cows inseminated with frozen semen produced by Rural Development Academy, Bogura. Methods: Data were collected from 372 cows at 39 villages under Sherpur Upazilla of Bogura district on breed, age, body condition score (BCS), parity, milk yield, suckling, AI season and the interval between oestrus to AI using a questionnaire. Results: The overall FSCR of cows was 66.4% and the service per conception was 1.53. The FSCR was higher (74.1%) in local cows compared to the Holstein-Friesian (HF) cross counterpart (64.2%). The FSCR was higher (70.4%) in 24-47 months old cows compared to 84-98 months old counterpart (61.5%). The highest FSCR (81.6%) was observed in cows with 3.0 to 3.5 BCS and the lowest (25.7%) was observed in cows with 2.5 BCS. The highest FSCR (68.3%) was observed in the 0 (zero) parity (heifers) group of cows and the lowest (62.5%) was observed in the 4-7 parity counterpart. The highest FSCR (72.4%) was observed in cows yielded daily >15-22 L milk and the lowest (62.1%) was observed in cows yielded ≤5 L milk. The highest FSCR (72.7%) was observed in suckling restricted cows and the lowest (60.9%) was observed in cows that had several times suckling daily. The highest FSCR (72.1%) was observed in cows received inseminations in Rainy (July-October) season and the lowest (58.4%) was observed in cows received inseminations in Winter (November-February). The highest FSCR (67.1%) was observed in cows received inseminations between 12-18 hrs of detection of oestrus and the lowest (59.1%) was observed in cows received insemination between 8-11 hrs of detection of oestrus. However, the difference in FSCR in cows with different BCS groups was significant (p<0.01). Conclusion: The current FSCR in cows can be considered to be satisfactory. The BCS of cows significantly influences the FSCR in cows.