在肉牛发情前期注射环戊丙酸雌二醇以及在首次发情期补充孕酮对卵巢和繁殖性能的影响。
Impact of estradiol cypionate prior to TAI and progesterone supplementation at initial diestrus on ovarian and fertility responses in beef cows.
作者信息
Martins T, Talamoni J P, Sponchiado M, Maio J R G, Nogueira G P, Pugliesi G, Binelli M
机构信息
Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, São Paulo, Brazil.
Department of Animal Reproduction, School of Veterinary Medicine, Camilo Castelo Branco University, Descalvado, São Paulo, Brazil.
出版信息
Theriogenology. 2017 Dec;104:156-163. doi: 10.1016/j.theriogenology.2017.08.017. Epub 2017 Aug 19.
In cattle, early diestrus progesterone (P4) supplementation modulates endometrial function to exert pro- and anti-pregnancy establishment effects; specifically, P4 stimulates conceptus growth, but also induces early onset of luteolysis. This paradoxical effect is frequently related to the inconsistent fertility outcomes that result from P4 supplementation experiments. Aim was to investigate the impact of exogenous estradiol (E2) treatment at the end of timed fixed AI (TAI) on frequency of early luteolysis and pregnancy of beef cows supplemented with P4. Ovulations (D0 of study) of suckled multiparous (n = 643) and primiparous (n = 193) Nelore cows (Bos indicus) were synchronized with an E2/P4-based protocol for TAI and assigned to receive 1.0 mg of estradiol cypionate (CP) or nothing (NoCP) on D-2 and 150 mg of injectable long-acting P4 (iP4) or Placebo (NoiP4) on D4 on a 2 × 2 factorial arrangement. On D15, the iP4 supplementation increased (P < 0.05) the frequency of early luteolysis (NoCP + iP4: 26.0%; [13/50] vs. NoCP: 8.0% [4/50]), but CP prevented this effect (CP + iP4: 8.3% [4/48] and CP: 6.4% [3/47]). The CP improved pregnancy/AI (P/AI) of multiparous (CP: 51.6% [165/320] and NoCP: 35.0% [113/323]; P < 0.001) and primiparous cows (CP: 40.4% [40/99] and NoCP: 24.5% [23/94], P < 0.05), regardless of iP4 treatment. The iP4 supplementation affected P/AI of CP and NoCP treated cows according to follicle size at TAI. For the CP treated cows, the iP4 supplementation improved P/AI of sub-populations of cows with follicles <12.35 mm (42.0% [34/81] vs. 53.1% [34/64]), while for NoCP treated cows, the improvements occurred in subpopulations of cows with follicles ≥12.35 mm (46.1% [35/76] vs. 58.7% [37/63]). In conclusion, strategies associating E2 and P4 supplementation decrease the incidence of early onset of luteolysis and improve P/AI of suckled beef cows with smaller follicles.
在牛中，在发情间期早期补充孕酮（P4）可调节子宫内膜功能，从而产生促进和抑制妊娠建立的作用；具体而言，P4可刺激孕体生长，但也会诱导黄体过早溶解。这种矛盾的效应通常与P4补充实验导致的生育结果不一致有关。本研究旨在调查在定时人工授精（TAI）结束时进行外源性雌二醇（E2）处理对补充P4的肉牛早期黄体溶解频率和妊娠情况的影响。对哺乳的经产（n = 643头）和初产（n = 193头）内罗牛（印度瘤牛）的排卵（研究第0天）采用基于E2/P4的方案进行同步化处理，以进行TAI，并按照2×2析因设计，在第 - 2天给牛只注射1.0毫克环丙孕酮（CP）或不注射（无CP），在第4天注射150毫克长效注射用P4（iP4）或安慰剂（无iP4）。在第15天，补充iP4增加了（P < 0.05）早期黄体溶解的频率（无CP + iP4组：26.0% [13/50]，无CP组：8.0% [4/50]），但CP可防止这种效应（CP + iP4组：8.3% [4/48]，CP组：6.4% [3/47]）。CP提高了经产牛（CP组：51.6% [165/320]，无CP组：35.0% [113/323]；P < 0.001）和初产牛（CP组：40.4% [40/99]，无CP组：24.5% [23/94]，P < 0.05）的妊娠/人工授精率（P/AI），与iP4处理无关。根据TAI时卵泡大小，补充iP4对CP和无CP处理的牛的P/AI有影响。对于CP处理的牛，补充iP4提高了卵泡<12.35毫米的牛亚群的P/AI（42.0% [34/81]对53.1% [34/64]），而对于无CP处理的牛，卵泡≥12.35毫米的牛亚群的P/AI有所提高（46.1% [35/76]对58.7% [37/63]）。总之，联合补充E2和P4的策略可降低早期黄体溶解的发生率，并提高卵泡较小的哺乳肉牛的P/AI。
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