Guner Baris, Kulaksiz Recai, Saat Nevzat, Kisadere Ihsan, Ozturkler Melek, Dalginli Kezban Yildiz, Pancarci Sukru Metin
Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, Balikesir University, Balikesir, Turkey.
Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Balikesir University, Balikesir, Turkey.
Vet Med (Praha). 2022 Feb 24;67(5):231-239. doi: 10.17221/244/2020-VETMED. eCollection 2022 May.
The objective of the study was to investigate the effect of pre-synchronisation on the occurrence of the oestrus and pregnancy rate after fixed time artificial insemination (FTAI) in synchronised ewes during the anoestrous season. Kivircik ewes ( = 84) were randomly assigned to one of the two treatment groups with (PRE; = 42) or without (SYN; = 42) pre-synchronisation. In the SYN group, the ewes were subjected to a 7-d short-term protocol (P4 insertion-6d-PGF2α-1d-P4 removal + eCG). In the PRE group, the same short-term protocol as in the SYN group was applied with 7 days apart for a pre-synchronised synchronisation protocol. A cervical FTAI was performed with fresh semen at 54 h after sponge removal. At the beginning of the synchronisation protocol, the oestrous response (66.7% vs. 0.0%) and cyclicity rates (64.3% vs. 14.3%) based on progesterone (P4) were higher in the PRE group compared to those in the SYN group, respectively (< 0.01). However, the oestrous response after synchronisation was lower within 96 h (57.1% vs. 95.2%; < 0.01) in the PRE group compared to that in the SYN group. Although the pregnancy rate after the FTAI was significantly (< 0.05) lower in the PRE group (14.3%) than the SYN group (35.7%), the overall pregnancy rate after natural mating was not different (95.2%) between the groups. In conclusion, the pre-synchronisation decreased the oestrous response leading to a lower pregnancy rate after the FTAI in the synchronised ewes during the anoestrous season. Thus, attention should be paid to two consecutive administrations of eCG in a pre-synchronisation and synchronisation protocol in ewes.
本研究的目的是调查在乏情季节对同期发情母羊进行预同步处理对定时人工授精（FTAI）后发情发生情况和妊娠率的影响。将84只基维里克母羊随机分为两个处理组之一，一组进行预同步处理（PRE；n = 42），另一组不进行预同步处理（SYN；n = 42）。在SYN组中，母羊接受为期7天的短期方案（插入孕酮栓 - 6天 - 注射前列腺素F2α - 1天 - 取出孕酮栓 + 注射孕马血清促性腺激素）。在PRE组中，应用与SYN组相同的短期方案，但间隔7天进行预同步处理方案。在取出海绵栓后54小时，用新鲜精液进行子宫颈FTAI。在同步处理方案开始时，基于孕酮（P4）的发情反应（66.7%对0.0%）和发情周期率（64.3%对14.3%）在PRE组中分别高于SYN组（P < 0.01）。然而，在96小时内，PRE组同步处理后的发情反应低于SYN组（57.1%对95.2%；P < 0.01）。虽然PRE组FTAI后的妊娠率（14.3%）显著低于SYN组（35.7%）（P < 0.05），但两组自然交配后的总体妊娠率无差异（95.2%）。总之，预同步处理降低了发情反应，导致乏情季节同期发情母羊FTAI后的妊娠率降低。因此，在母羊的预同步处理和同步处理方案中应注意连续两次注射孕马血清促性腺激素。
