SYNCHRONIZATION OF ESTRUS AND FERTILITY IN SHEEP OF THE NORTHEASTERN BULGARIAN FINE–WOOLEN BREED – SHUMEN TYPE BY DIFFERENT PROGESTOGEN TREATMENTS AND DIFFERENT DOSES OF PMSG

The aim of the present study was to test three protocols for synchronization of estrus and fertility in merino sheep. 3 experimental groups were formed, depending on the duration of progestagen treatment (FGA sponges) and PMSG dose: Group 1 (n = 12) – 12 days + 500 UI. Group 2 (n = 12) – 12 days + 250 UI. Group 3 (n = 11) – 5 days (at the time of sponge placement, sheep were treated with a synthetic analogue of PGF2α) + 500 UI. On the three groups, PMSG was injected at the time of sponge removal. At the 48th hour of sponge removal, the highest number of ewes in the estrus was in the Group 2–12 sheep, while in the others it was 9 (Group 1) and 6 (Group 3). The highest values for fertility and fecundity were obtained in sheep from Group 1–41.66% and 160.0%