Research Information System
KAFKAS UNIVERSITESI VETERINER FAKULTESI DERGISI, vol.19, no.4, pp.629-633, 2013 (SCI-Expanded)
The effects of different synchronisation prototocols on the reproductive parameters of fat-tailed ewes during the breeding season were studied herein. Seventy-one multiparous fat-tailed ewes were randomly divided into four treatment groups, as follows; Group 1 (long-term FGA): for a total of 20 ewes, 20 mg FGA sponges inserted intravaginally for 14 d, plus an i.m. injection of 400 IU PMSG upon the sponge withdrawal, Group 2 (short-term FGA): for 18 ewes, the insertion of sponges for 8 d, plus the PMSG injection on day 8 upon the sponge withdrawal, Group 3 (Ovsynch): for 17 ewes, an i.m. injection of 0.004 mg GnRH on day zero, followed by the injection of 125 mu g PGF(2a) on day 7 and the second GnRH injection on day 9, and Group 4 (short-term FGA plus Ovsynch): for 16 ewes, the FGA sponge inserted along with the first GnRH injection (as day zero), PGF(2a) injection on day 7 upon the sponge withdrawal, and the second GnRH injection on day 9. The results showed that; time to onset of oestrus (P<0.001), duration of oestrus (P<0.05), the rates of pregnancy (P<0.01) and lambing (P <= 0.001) differed between the synchronisation groups. Overall, findings of onset/duration of oestrus and pregnancy/lambing rates suggest that; the standard Ovsynch synchronisation programme was markedly inferior to the long-and short-term FGA sponge protocols in fat-tailed ewes during the breeding season.