Carrera-Chávez J M, Hernández-Cerón J, López-Carlos M A, Lozano-Domínguez R R, Molinar F, Echavarría-Cháirez F G, Bañuelos-Valenzuela R, Aréchiga-Flores C F
Unidad Académica de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Zacatecas, Carretera Panamericana Zacatecas-Fresnillo Km 31.5, 98500 El Cordovel Enrique Estrada, Zacatecas, Mexico.
Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad 3000, 04510 México, DF, Mexico.
Anim Reprod Sci. 2014 Dec 30;151(3-4):105-11. doi: 10.1016/j.anireprosci.2014.10.009. Epub 2014 Oct 22.
This study evaluated whether the administration of 50 and 100mg bovine somatotropin (bST) at the start of synchronization and at the time of natural mating in ewes improves the ovulation rate, embryonic development and pregnancy rate of transferred embryos. Forty-eight donors were assigned to three treatments: the bST-100 treatment (n=15) received 100mg bST at the start of synchronization and at natural mating, the bST-50 treatment (n=15) received 50mg bST on the same schedule as the previous group, and the control (n=18) did not receive any bST. Two embryos were transferred to each recipient (n=121): 35 received embryos from bST-100; 50 received embryos from bST-50, and 36 received embryos from the control. The superovulatory rate, percentage of recovered structures, cleavage rate, percentage of transferable embryos, embryo quality and development and pregnancy rate were analyzed using the GENMOD procedure of SAS. The number of corpora lutea and the cell number were analyzed using the GLM procedure of SAS. The insulin and IGF-1 concentrations were analyzed with ANOVA for repeated measures. The bST application did not affect the superovulatory rate, number of corpora lutea and recovered structures (P>0.05). The numbers of transferable embryos and embryos reaching the blastocyst were higher (P≤0.01) in the bST-50 (96.4±3.6% and 69.0±7.8%) than the bST-100 (93.0±4.5% and 27.2±38.9%) and control (87.7±5.4% and 50.4±6.4%) groups. The insulin and IGF-1 concentrations were higher (P<0.05) in the bST-treated groups, but the insulin concentration was higher (P<0.05) in the bST-100 group than in the bST-50 group. The pregnancy rate was similar (P=0.21) in ewes receiving embryos from the two treatments [bST-50, (70.0%); bST-100, (62.5%), and control, (56.6%)]. The administration of 50mg bST at the start of synchronization and at natural mating in superovulated ewes was concluded to enhance the proportion and development of transferable embryos. However, bST did not affect the pregnancy rate of transferred embryos.
本研究评估了在母羊同步发情开始时及自然交配时给予50毫克和100毫克牛生长激素（bST）是否能提高排卵率、胚胎发育及移植胚胎的妊娠率。48只供体母羊被分为三个处理组：bST - 100处理组（n = 15）在同步发情开始时及自然交配时接受100毫克bST；bST - 50处理组（n = 15）按与前一组相同的时间表接受50毫克bST；对照组（n = 18）不接受任何bST。将两枚胚胎移植到每只受体母羊（n = 121）：35只接受来自bST - 100组的胚胎；50只接受来自bST - 50组的胚胎；36只接受来自对照组的胚胎。使用SAS的GENMOD程序分析超排卵率、回收结构的百分比、卵裂率、可移植胚胎的百分比、胚胎质量及发育情况和妊娠率。使用SAS的GLM程序分析黄体数量和细胞数量。使用重复测量的方差分析（ANOVA）分析胰岛素和IGF - 1浓度。bST的应用不影响超排卵率、黄体数量和回收结构（P>0.05）。bST - 50组（96.4±3.6%和69.0±7.8%）可移植胚胎和发育至囊胚阶段胚胎的数量高于bST - 100组（93.0±4.5%和27.2±38.9%）及对照组（87.7±5.4%和50.4±6.4%）（P≤0.01）。bST处理组的胰岛素和IGF - 1浓度较高（P<0.05），但bST - 100组的胰岛素浓度高于bST - 50组（P<0.05）。接受两种处理组胚胎的母羊妊娠率相似（P = 0.21）[bST - 50组，（70.0%）；bST - 100组，（62.5%），对照组，（56.6%）]。得出结论，在超排母羊同步发情开始时及自然交配时给予50毫克bST可提高可移植胚胎的比例和发育情况。然而，bST不影响移植胚胎的妊娠率。
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