Endocrine, luteal and follicular responses after the use of the Short-Term protocol to synchronize ovulation in goats

Abstract The effect of the so-called Short-Term Protocol (5-day progesterone treatment + PGF 2 α) on ovarian activity and LH surge was studied in goats. The goats received 250 IU eCG at the time of device withdrawal (eCG group; n  = 7), or 200 μg of EB (estradiol benzoate) 24 h after device withdrawal (EB group; n  = 8), or received neither eCG nor EB (control group; n  = 8). The Short-Term Protocol induced greater (4.1 ± 1.1 ng/ml) progesterone serum concentrations at 24 h after start of the treatment, that declined to 0.2 ± 0.1 ng/ml at 12 h after device withdrawal. In all of the groups, the maximum concentration of estradiol-17β was reached at about 36 h after device withdrawal. Maximum concentration was greater in the EB group (76.9 ± 24.6 pmol/l) than in the control group (41.8 ± 9.0 pmol/l; P P  = NS). The LH peak occurred earlier in the eCG group (38.4 ± 2.0 h after device withdrawal) and in the EB group (41.0 ± 4.1 h), than in the control group (46.3 ± 5.1 h; P P