Efficacy of different protocols of ovulation synchronization and resynchronization in argentinian buffalo herds

Abstract

During the last years bufalo reproductive researchers have been tried to develop and apply fxed timed artifcial insemination protocols to increase pregnancy rates to maximize improvement. The objective of this paper is to evaluate the pregnancy rates of diferent protocols of synchronization (Ovsynch and progesterone implants) and resynchronization of ovulation in a meat water bufalo herd during reproductive season of 2016. 194 mature Mediterranean females, were randomly assigned to four diferent protocols, ultrasound evaluation were used to determine cyclicity (presence of corpus luteum or follicles ≥7 mm de diameter). 18 days after insemination all females were resynchronized and at day 25 ultrasound were performed, those nonpregnant females were inseminated 28 days after frst insemination. All inseminations were performed by the same technician and only one bull was used. InfoStat software was used, statistical signifcance was considered when p value was lower than α

of the 5%. No statistical signifcance were found within the protocols. Early embryonic dead 50 days after IA was 3.4%. Pregnancy rate was 47.9% and 53.5% for insemination and reinsemination respectively and the fnal pregnancy rate after the adjust for early pregnancy loss 73.2%, during the 28 days of the breeding period. The results obtained allow breeders to choose the best pharmacological option to use FTAI in their herds based on their own needs to improve production without afecting pregnancy rates.