Timing-dependent reproductive outcomes of intrauterine antiseptic and antibiotic interventions following artificial insemination in dairy cows: effects on pregnancy and early embryonic loss

The aim of this study was to evaluate the effects of povidone-iodine and oxytetracycline, administered intrauterinely at different time points following artificial insemination, on pregnancy rates and embryonic losses in dairy cows. The study was conducted on a total of 350 clinically healthy Holstein cows, synchronized using the Ovsynch protocol, between 50 and 60 days postpartum. The animals were randomly assigned to a control group and six experimental groups that received povidone-iodine (PI) or oxytetracycline (OTC) 4, 12, and 24 h after artificial insemination. Pregnancy rates and embryonic loss rates following the first insemination were determined via ultrasonographic examinations conducted between 1 and 4 months after insemination. According to the results, while no statistically significant difference was found in pregnancy rates, the lowest embryonic loss rate (6.7%) was observed in the group treated with oxytetracycline 12 h after artificial insemination. In contrast, the highest embryonic loss rate (27.8%) was observed in the control group. Overall, it was determined that the groups treated with oxytetracycline demonstrated better fertility outcomes compared to the groups treated with povidone-iodine across all time periods. In conclusion, it was concluded that intrauterine oxytetracycline administered after artificial insemination, particularly at the 12-hour mark, reduces embryonic losses; therefore, intrauterine antibiotic administration at the appropriate time may be an effective approach for improving fertility in dairy cows.