TDK conference 2018

Today's modern 21st-century animal husbandry is hardly imaginable without the application of methods belonging to the group of assisted reproductive technologies, such as estrus synchronization or artificial insemination (AI), that foster fertilization and thus improving productivity. Our study was conducted in a sheep-farm, where all ewes are fertilized only with AI, and we were trying to find out with which estrus synchronization protocol could we fertilize those ewes that remained non-pregnant near the end of the breeding season. In our study we compared three types of estrus synchronization protocols in order to find out whether eCG, which was difficult to obtain last year, could be replaced with a GnRH agonist, and whether there is a difference in the conception rate between the different treatment groups and the control group and furthermore how the different treatments affect the estrus. The study included 70 ewes, whose cycles were synchronized with Chronogest CR intravaginal sponges impregnated with 20 mg fluorogestone acetate (FGA) active substance. Unfortunately due to technical reasons a total of 12 animals had lost their sponge, which was more than expected, so the groups were formed from the remaining 58 animals (GnRH (n = 20), eCG (n = 19), control (n = 19)). Blood was taken three times from the animals to determine the progesterone (P4) and the estradiol (E2) hormone levels: at the time of sponge removal and on the days of AI and the ultrasonographic pregnancy examination. After evaluating the blood results and the lambing data, we have come to the preliminary conclusion that eCG treatment was more effective in many aspects than the protocol applying GnRH after sponge removal.