GNRH-PGF2α and PGF2α-PGF2α synchronization in Akkaraman cross-bred sheep in the breeding season

The object of this trial was to determine the efficacy of GnRH-PGF 2? treatment to synchronize oestrus in sheep during the breeding season. A total of 30 ewes aging 18-24 months and 6 healthy rams aging 2-3 years were used in this experiment. Animals were divided into two groups. The first group received intramuscular (i.m.) injection of GnRH analogue (busereline) and 5 d later i.m. injection of PGF2? analogue (Triaprost tromethamine). The second group (control) was given twice, at 9 d interval, i.m. injection of PGF2?. Fourty-eight hours after the application of PGF2?, 400 IU of PMSG was injected i.m. to all the ewes. After the detection of oestrous, the ewes were hand-mated naturally. Pregnancy was determined using ultrasonography on d 30 after the mating. Multiple embryos were determined in each ewe using ultrasonography. Oestrus response, pregnancy, lambing rates, and litter sizes were 93.7%, 85.7%, 83.3% and 1.70; 86.6%, 84.6%, 81.8%, and 1.66 in the groups I and II, respectively. Therefore, GnRH-PGF2? treatment has been found to be effective in the synchronization of the oestrus in ewes.