Baruselli Pietro S, Ferreira Roberta M, Sá Filho Manoel F, Nasser Luiz F T, Rodrigues Carlos A, Bó Gabriel A
Departamento de Reprodução Animal, FMVZ-USP, CEP 05508-000 São Paulo, Brazil.
Reprod Fertil Dev. 2010;22(1):67-74. doi: 10.1071/RD09214.
Numerous studies have shown that it is possible to manipulate follicular and luteal dynamics, thereby eliminating the need for oestrus detection in embryo transfer (ET) programmes. Fixed-time ET (FTET) protocols are based on the use of gonadotrophin-releasing hormone (GnRH) and prostaglandin (PG) F or progesterone/progestogen (P4)-releasing devices and oestradiol. The FTET protocols increases the proportion of recipients transferred, and therefore pregnancy rates, compared with the use of PGF followed by ET 7 days after oestrus. Furthermore, the addition of equine chorionic gonadotrophin (eCG) to the P4 and oestradiol-based FTET protocols results in an even higher proportion of recipients transferred, and thus higher pregnancy rates. The beneficial effect of eCG treatment may be related to increased growth of the dominant follicle and increased plasma P4 concentrations during the subsequent luteal phase. In Bos taurus x Bos indicus recipients, pregnancy rates were positively correlated with the diameter of the corpus luteum (CL) and the number of CL at ET. When repeat-breeder Holstein cows were used as recipients, FTET protocols increased number of recipients transferred and pregnancy rates compared with the traditional PGF-based synchronisation protocols. In conclusion, the use of FTET protocols eliminates the need for the detection of oestrus and results in a greater proportion of recipients transferred and satisfactory pregnancy rates. Thus, FTET optimises the use of recipients, reducing labour and animal handling and facilitating the use of ET.
众多研究表明，操控卵泡和黄体动态是可行的，从而在胚胎移植（ET）程序中无需进行发情检测。定时胚胎移植（FTET）方案基于使用促性腺激素释放激素（GnRH）、前列腺素（PG）F或孕酮/孕激素（P4）释放装置以及雌二醇。与发情后7天使用PGF随后进行胚胎移植相比，FTET方案提高了接受移植受体的比例，进而提高了妊娠率。此外，在基于P4和雌二醇的FTET方案中添加马绒毛膜促性腺激素（eCG）会使接受移植受体的比例更高，从而妊娠率也更高。eCG处理的有益效果可能与优势卵泡生长增加以及随后黄体期血浆P4浓度升高有关。在瘤牛×印度瘤牛受体中，妊娠率与胚胎移植时黄体（CL）的直径和CL数量呈正相关。当将屡配不孕的荷斯坦奶牛用作受体时，与传统的基于PGF的同步方案相比，FTET方案增加了接受移植受体的数量和妊娠率。总之，使用FTET方案无需进行发情检测，导致接受移植受体的比例更高且妊娠率令人满意。因此，FTET优化了受体的使用，减少了劳动力和动物处理，并便于胚胎移植的应用。
