Ararooti Tahereh, Niasari-Naslaji Amir, Asadi-Moghaddam Behnam, Razavi Kamal, Panahi Farnaz
Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran; Camel Advanced Reproductive Technologies Centre, Government of Dubai, Dubai, United Arab Emirates.
Theriogenology. 2018 Jan 15;106:149-156. doi: 10.1016/j.theriogenology.2017.10.017. Epub 2017 Oct 13.
The objectives of this study were to compare three superovulation protocols and to investigate the effect of embryo diameter and shape on pregnancy rates in dromedary camel. In Experiment 1, following follicular wave synchronization of donors using two injections of GnRH (25 μg, im), superovulation was initiated 2 days after the second GnRH (Day 0 of experiment). Then, donors were assigned into three groups (n = 5) and received 1) FSH alone (390 mg), 2) eCG (1000 IU; single dose on Day 0) and FSH (330 mg) and 3) hMG (17.5 ampules). FSH and hMG were administered twice daily, in decreasing doses, for 5.5 days. Thirty-six hours after the last dose of FSH or hMG, donors were mated once. On Day 4 of superovulation, the diameter and number of follicles and on Day 7.5 after mating, total number of corpora lutea and follicles ≥9 mm were recorded using ultrasound examination. On Day 8.5 after mating, embryos were recovered non-surgically. In Experiment 2, on Day 6.5 after inducing ovulation, recipients (n = 139) received a single 7.5 days old hatched blastocyst. The diameter and shape (round, oval, collapsed) of transferred embryos were recorded. Pregnancy was detected on Day 25 after embryo transfer. Data were analyzed using Proc GLM, Proc FREG, Proc CORR and Proc Genmod of SAS. The number of corpora lutea was greater in FSH (22.4 ± 2.25) than eCG-FSH (11.6 ± 2.58) and hMG (7 ± 3.19; P < 0.01). Total number of embryos was higher in FSH (16.2 ± 2.72) than hMG (1.6 ± 1.17; P < 0.01). In FSH group, there was correlation between the ratio of follicles >6 mm/follicles ≤6 mm on Day 4 of superovulation and total number of corpora lutea (r = 0.9; P < 0.05) and embryos (r = 0.91; P < 0.05). In the latter group, there was also correlation between corpora lutea and number of embryos (r = 0.92; P < 0.05). Transfer of embryos collected from different superovulation protocols did not affect pregnancy rates (P > 0.05). The diameter of hatched blastocysts had significant effect on pregnancy rates (P < 0.05). Medium size embryos (601-985 μm) produced greater pregnancy rates (50.8%) compared to small (275-600 μm; 25%) and large (986-1571 μm; 32%) embryos (P < 0.05). In conclusion, FSH protocol provided better and predictable superovulatory response. Greater pregnancy rates could be achieved by transferring medium size hatched blastocysts in dromedary camel.
本研究的目的是比较三种超数排卵方案，并研究胚胎直径和形状对单峰骆驼妊娠率的影响。在实验1中，使用两次注射促性腺激素释放激素（GnRH，25μg，肌肉注射）使供体的卵泡波同步化，在第二次注射GnRH后2天（实验第0天）开始超数排卵。然后，将供体分为三组（n = 5），分别接受：1）单独使用促卵泡素（FSH，390mg）；2）马绒毛膜促性腺激素（eCG，1000IU，第0天单次注射）和促卵泡素（330mg）；3）人绝经期促性腺激素（hMG，17.5安瓿）。FSH和hMG每天分两次给药，剂量递减，持续5.5天。在最后一次注射FSH或hMG后36小时，让供体交配一次。在超数排卵第4天，使用超声检查记录卵泡的直径和数量，在交配后第7.5天，记录黄体总数和直径≥9mm的卵泡数量。在交配后第8.5天，通过非手术方法回收胚胎。在实验2中，在诱导排卵后第6.5天，受体（n = 139）接受一枚7.5日龄的孵化囊胚。记录移植胚胎的直径和形状（圆形、椭圆形、塌陷形）。在胚胎移植后第25天检测妊娠情况。使用SAS的Proc GLM、Proc FREG、Proc CORR和Proc Genmod程序对数据进行分析。FSH组的黄体数（22.4±2.25）多于eCG-FSH组（11.6±2.58）和hMG组（7±3.19；P<0.01）。FSH组的胚胎总数（16.2±2.72）高于hMG组（1.6±1.17；P<0.01）。在FSH组中，超数排卵第4天直径>6mm的卵泡数与直径≤6mm的卵泡数之比与黄体总数（r = 0.9；P<0.05）和胚胎总数（r = 0.91；P<0.05）之间存在相关性。在hMG组中，黄体数与胚胎数之间也存在相关性（r = 0.92；P<0.05）。从不同超数排卵方案收集的胚胎进行移植对妊娠率没有影响（P>0.05）。孵化囊胚的直径对妊娠率有显著影响（P<0.05）。中等大小的胚胎（601 - 985μm）产生的妊娠率（50.8%）高于小胚胎（275 - 600μm；25%）和大胚胎（986 - 1571μm；32%）（P<0.05）。总之，FSH方案提供了更好且可预测的超数排卵反应。通过移植中等大小的孵化囊胚，单峰骆驼可获得更高的妊娠率。
