The efficacy of eight combinations of fluorogestone acetate (FGA, 20 or 40 mg as intravaginal device during 11 days), equine chorionic gonadotropin (eCG, 300 or 500 UI injected 48 hours before FGA removal) and prostaglandin F2α (cloprostenol, 0 or 50 μg injected 48h before FGA removal) aiming at induction and synchronization of oestrus and ovulation was evaluated during the anoestrus season in spring and during the breeding season in autumn in adult Beni Arouss goats. Oestrus behaviour was recorded between 12 and 60 hours after FGA removal. Blood samplings allowing to assess onset of the preovulatory LH surge and increase of progesterone as sign of an active corpus luteum were performed respectively between 20 and 60 hours and 3, 5, 8 and 15 days after FGA removal. No season-related differences (spring versus autumn) were observed for oestrus response (95 versus 93%), preovulatory LH surge (94 versus 84%) and luteal response after 3 to 8 and 11 to 15 days post-treatment (respectively 92 versus 66% and 92 versus 98%). The onset of oestrus (21 [13-53] versus 32 [12-54] hours) and LH surge (26 [20-60] versus 38 [22-60] hours) occurred significantly later in autumn. FGA (40 versus 20 mg) in autumn significantly delayed the onset of oestrus (36 [16-54] versus 23 [12-47] hours) and LH surge (44 [26-58] versus 33 [22-60] hours). Significant treatment-related differences were recorded for onset of LH surge (earliest for 20 mg FGA, 300 IU eCG, 50 μg PGF2α ) and onset of luteal phase (latest for 40 mg FGA, 300 IU eCG, 50 μg PGF2α ). In conclusion, the hormone combinations tested appeared equally effective in terms of oestrus and ovulation rates. Season has influenced significantly the onset of oestrus and LH surge and the high dose regimen of FGA delayed the ovarian response in autumn.
- LH surge
- breeding season
- hormonal treatment
El Kadili, S., Raes, M., Bister, J-L., Beckers, J-F., Amzati Sefu, G., Archa, B., Chentouf, M., & Kirschvink, N. (2019). Evaluation of different hormonal treatments on oestral and ovarian responses in Moroccan Beni Arouss goats during anoestrus and breeding season. Reproduction in Domestic Animals, 54(7), 1003-1009. https://doi.org/10.1111/rda.13454