Brozos Christos, Kiossis Evangelos, Hatzieffraimidis Savvas, Praxitelous Anastasia, Gouvias Ioannis, Kanoulas Vasileios, Tsousis Georgios
Clinic of Farm Animals, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece.
CEVA Hellas, 16341 Ilioupoli, Greece.
Animals (Basel). 2021 Oct 13;11(10):2955. doi: 10.3390/ani11102955.
The aim of this study was to evaluate the efficacy of two timed-AI (TAI) protocols (Group G5D, GnRH and PRID -5d- PGF2a -1d- PGF2a -1d- GnRH, = 105 and Group G7D, GnRH and PRID-7d- PGF2a -1d- PGF2a -1d- GnRH, = 98) and a modified G7G protocol combining heat detection (HD) and AI or TAI if HD failed (Group HD, GnRH and PRID -7d- PGF2a -1d- PGF2a -5d- HD or 5d TAI if no HD, = 92). Pregnancy per AI (P/AI) did not differ between G5D and G7D protocol (G5D: 33.8% vs. G7D: 35.2%, P = 0.85). Cows assigned to G5D and G7D group were pooled as TAI group (GTAI) and further compared to GHD. Within the GHD, more primiparous cows exhibited estrous signs compared to multiparous cows (70.4% vs. 46.2%, P = 0.03). Furthermore, 49 cows (53.3%) were served after HD, whereas 43 cows (46.7%) were served after TAI. There was no difference in P/AI between cows served after HD (51.6%) or after TAI (43.0%, P = 0.49). GHD showed higher P/AI at 1st service compared to GTAI (49.1% vs. 36.4%, P = 0.04), whilst, median days to pregnancy did not differ between the two groups. Overall, P/AI of primiparous cows tended to be better in comparison with multiparous cows (48.3% vs. 37.2%, P = 0.06). In conclusion, there was no significant difference regarding the efficacy of 5- and 7-day Ovsynch + PRID protocols. Moreover, a modified G7G protocol, with intermediate heat detection, resulted in overall better P/AI compared to TAI protocols and appears as a promising strategy to optimize estrus detection for 1st AI.
本研究的目的是评估两种定时人工授精（TAI）方案（G5D组，促性腺激素释放激素（GnRH）和孕酮释放激素装置（PRID）-5天-前列腺素F2α-1天-前列腺素F2α-1天-GnRH，n = 105；以及G7D组，GnRH和PRID-7天-前列腺素F2α-1天-前列腺素F2α-1天-GnRH，n = 98）和一种改良的G7G方案（结合发情检测（HD），若HD失败则进行人工授精或TAI）（HD组，GnRH和PRID -7天-前列腺素F2α-1天-前列腺素F2α-5天- HD，若无HD则进行5天TAI，n = 92）的效果。G5D和G7D方案之间的每次人工授精妊娠率（P/AI）没有差异（G5D：33.8% 对 G7D：35.2%，P = 0.85）。分配到G5D和G7D组的奶牛合并为TAI组（GTAI），并与HD组进一步比较。在HD组中，初产奶牛出现发情迹象的比例高于经产奶牛（70.4% 对 46.2%，P = 0.03）。此外，49头奶牛（53.3%）在HD后进行配种，而43头奶牛（46.7%）在TAI后进行配种。HD后配种的奶牛与TAI后配种的奶牛之间的P/AI没有差异（51.6% 对 43.0%，P = 0.49）。与GTAI相比，HD组第一次配种时的P/AI更高（49.1% 对 36.4%，P = 0.04），而两组之间的妊娠中位天数没有差异。总体而言，初产奶牛的P/AI与经产奶牛相比有更好的趋势（48.3% 对 37.2%，P = 0.06）。总之，5天和7天的奥同步 + PRID方案在效果上没有显著差异。此外，一种改良的G7G方案，结合中间发情检测，与TAI方案相比，总体上P/AI更高，似乎是优化首次人工授精发情检测的一种有前景的策略。
