Different estrous induction protocols during the transition period in lactating Turkish Saanen does following Al

Abstract

The objective of this study was to evaluate the duration of three progestagen treatments for estrous synchronization in lactating Turkish Saanen goats during the transitional period from anestrous. All does (n = 60) were divided into three equal groups and the estrous period of the does was synchronized using intravaginal sponges (20 mg FGA) for either 11 days (Group 1), 9 days (Group 2) or 6 days (Group 3). In addition, 24h before sponge removal (on the 10(th) day, 8(th) day and 5(th) day, respectively) each doe was injected with 0.075 mg cloprostenol (PGF(2 alpha)) and 500 IU eCG. Cervical artificial inseminations (Al) with frozen-thawed semen were performed at fixed intervals (36 and 48 h) following progestagen withdrawal. The total estrous response following the first withdrawal was 12 +/- 6 h within 66 h. Time to onset and duration of the induced estrous, and pregnancy rates were recorded to be 30.0%, 100%, 23.9 +/- 0.7 h, 29.4 +/- 1.3 h, and 28.3%, respectively. There were significant differences between Group 1 and the other groups, in terms of the onset of induced estrus (P<0.05) and estrous response for the first 12 +/- 6 h (P<0.05) and between Group 2 and Groups 1 and 3 in terms of the duration of induced estrous (P<0.05). Each of the three protocols was effective in inducting and synchronizing estrus in lactating Turkish Saanen goats.