Research Information System
Joint Meeting of the 20th Annual Conference of the European-Society-for-Domestic-Animal-Reproduction (ESDAR) / 13th Conference of the Spanish-Association-for-Animal-Reproduction (AERA), Lisbon, Portugal, 27 - 29 October 2016, pp.138-139
The objective of the study was to determine the effect of 3 different PGF2α treatments in a 5-day CO-Synch progesterone-based synchronization protocol on AI pregnancy rates in Holstein heifers in Cukurova region, Turkey. We hypothesized that two doses of PGF2α (PGF) administered concurrently or 6 h apart would result in greater AI pregnancy compared to single dose of PGF on Day 5 at CIDR (Controlled internal drug release) removal. Heifers were randomly assigned to one of these groups: 1 PGF - received 25 mg IM of Dinoprost at CIDR removal; 2 CoPGF - received 50 mg IM of Dinoprost at CIDR removal, and 2 PGF - received 25 mg IM of Dinoprost at CIDR removal and an additional 25 mg IM of Dinoprost 6 h later. All heifers received a CIDR (1.38 g of progesterone) and 10 μg IM of Buserelin on Day 0. The CIDRs were removed on Day 5, and each heifer was given PGF based on the assigned treatments. On day 7, each heifer was given Buserelin (10 μg IM) and artificially inseminated at 56 h after CIDR removal. Heifers were examined for pregnancy status 45 days after AI. No significant differences were found in pregnancy rates after AI in heifers treated with 2PGF at 6 h apart compared to heifers treated with 2Co-PGF [45% (9/20); p > 0.05] or 1 PGF [55% (11/20); p > 0.05]. No difference was observed between 2Co-PGF and 1 PGF groups (p > 0.05). In conclusion, pregnancy rates obtained after the protocol of 2PGF at 6 h apart on Day 5 at CDIR removal in a 5-Day CO-Synch + CIDR were similar but not greater than the single dose protocol of PGF.