Zampini Enzo German, Veiga Maria Fernanda, Fumuso Fernanda Gabriela, Cabido Luciana, Neild Deborah Margarita, Chaves Maria Graciela, Miragaya Marcelo Horacio, Trasorras Virginia Luz
Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Instituto de Investigación y Tecnología en Reproducción Animal, Cátedra de Teriogenología, Buenos Aires, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.
Front Vet Sci. 2020 Nov 12;7:595889. doi: 10.3389/fvets.2020.595889. eCollection 2020.
The aim of the present study was to evaluate the application of a GnRH-PGF based synchronization and superstimulation protocol for fixed-time natural mating in llama embryo donors. All females ( = 8) received 8 μg IM of GnRH analog (GnRHa; buserelin) on day 0, regardless of follicular status. After eight days, another GnRHa dose was administered followed by 250 μg IM PGF (cloprostenol). A dose of 1000 IU IM of equine chorionic gonadotrophin (eCG) was applied on day 12 and a new dose of PGF was administered on day 13. All embryo donors were mated with a male of proven fertility followed by a GnRHa dose on day 18. 24 h later, mating was repeated with a different male. Transcervical uterine flushing for embryo recovery was carried out on all females on day 26. Recipient females received one dose of GnRHa (day 0) two days after the first mating of embryo donor females. A 75% (6/8) of embryo donors responded to the superstimulation treatment with a range of 2 to 5 corpus luteums (CLs) on embryo recovery day. A total of 24 CLs were registered, with a mean of 4 ± 0.9 CLs per female. Embryo recovery rate was 66.7% (16/24), with a range of 0 to 4 embryos and a mean of 2.7 ± 1.5 embryos per female. Regarding quality of the recovered embryos, 56.2% were grade I, 6.2% were grade II and 37.5% were grade V (untransferable; arrested morulae). Grade I and II embryos ( = 10) were transcervically transferred into recipient females ( = 10) six days after inducing their ovulation. At 24 days after embryo transfer (ET), a 50% pregnancy rate was registered. In conclusion, a group of llama embryo donors can be synchronized and superstimulated using a fixed-time mating protocol based on GnRHa, PGF, and eCG without the necessity of using ultrasonography in the field.
本研究的目的是评估基于促性腺激素释放激素（GnRH）-前列腺素F2α（PGF）的同步化和超刺激方案在羊驼胚胎供体定时自然交配中的应用。所有雌性（n = 8）在第0天接受8 μg肌肉注射促性腺激素释放激素类似物（GnRHa；布舍瑞林），无论卵泡状态如何。八天后，再次给予GnRHa剂量，随后肌肉注射250 μg PGF（氯前列醇）。在第12天肌肉注射1000 IU马绒毛膜促性腺激素（eCG），并在第13天给予新的PGF剂量。所有胚胎供体与一只经证实有生育能力的雄性交配，随后在第18天给予GnRHa剂量。24小时后，与另一只不同的雄性再次交配。在第26天对所有雌性进行经宫颈子宫冲洗以回收胚胎。受体雌性在胚胎供体雌性首次交配两天后接受一剂GnRHa（第0天）。75%（6/8）的胚胎供体对超刺激处理有反应，在胚胎回收日有2至5个黄体（CLs）。总共记录到24个CLs，平均每只雌性4 ± 0.9个CLs。胚胎回收率为66.7%（16/24），每只雌性的胚胎数范围为0至4个，平均为2.7 ± 1.5个。关于回收胚胎的质量，56.2%为I级，6.2%为II级，37.5%为V级（不可移植；桑葚胚停滞）。I级和II级胚胎（n = 10）在诱导排卵六天后经宫颈移植到受体雌性（n = 10）体内。在胚胎移植（ET）后24天，妊娠率为50%。总之，一组羊驼胚胎供体可以使用基于GnRHa、PGF和eCG的定时交配方案进行同步化和超刺激，而无需在现场使用超声检查。
