Efficiency of superovulatory response to P-24 protocol in fixed time embryo transfer in Brahman cattle

Objective. To evaluate the efficiency of superovulatory response to P-24 protocol in fixed time embryo transfer in Brahman cattle. Materials and methods. Twelve Brahman cows donors with more than 60 days postpartum were used. Twenty one cows received a superovulatory treatment based in Protocol P-24. Embryos were collected through the conventional method, and the embryos were classified (IETS). Results. An average of 9.1 embryos were collected, 4.4 were considered for direct transfer, 3.7 were considered for freezing and 3.2 were classified as degenerated. According to the stage embryos were classified as: morulae (32.6%), early blastocyst (38%) and blastocyst (18.5%). Effect was presented (p<0.05) in the number of successive superovulations on the production of frozen embryos; however, there was no effect (p>0.05) on the other variables studied. Effect was presented (p<0.05) in the average production of structures recovered, and transferable and frozen embryos among the donors with an output greater than or equal to 5, and less than 5 transferable embryos. By contrast, there was no effect (p>0.05) on the average production of degenerate embryos and unfertilised oocytes among both groups. Nevertheless, the proportion of these ones is greater in the donors with a lower production of transferable embryos (50 and 22.4%) vs. donor with the highest production (39.3 and 14%) for degenerated embryos and unfertilised oocytes respectively. Conclusions. The Brahman cattle has an efficient superovulatory response to P-24 protocol for fixed time embryo transfer.