Association of the early pregnancy diagnosis to a protocol of estrus resyncronization in zebu cows

Abstract

The purpose of this study was to develop a resynchronization strategy, without estrus detection, which lead a service rate of 100% for those cows that were not pregnant after the first FTAI. Thus, 40 Tabapuã cows received on D0 a CIDR and 2mg of Estradiol Benzoate (EB) intramuscular (IM). On D8, the devices were removed and animals received 75mg of D-Cloprostenol intra-vulvo-submucosal (IVSM) and 200IU of eCG IM. On D9, 1mg of BE IM was administered and on D10, 52 at 56 hours after the devices removal, the FTAI was accomplished. Twenty two days after inseminations (D32), 50% of the animals had CIDR reinserted and received 1mg of EB IM. On D40, the devices were removed and pregnancy diagnosis was performed by ulltrasonography, the non-pregnant cows received 75mg of D-Cloprostenol IVSM and 200IU of eCG IM. On D4, it was administered 1mg of EB IM and FTAI on D42. Pregnancy diagnosis was accomplished 30 days after the FTAI. Pregnancy rates of non-resynchronized animals and resynchronized were respectively, 50 and 75% and there was not statistics difference among groups. Despite of these results, the resynchronization increased the pregnancy rate, in a period of 42 days, without estrus etection, and offered two conception opportunities for all cows.