Department of Theriogenology, Faculty of Veterinary Medicine, Kafr El-Sheikh University, 13561 Kafr El-Sheikh, Egypt.
Anim Reprod Sci. 2010 May;119(1-2):17-23. doi: 10.1016/j.anireprosci.2009.12.005. Epub 2009 Dec 16.
The aim of the present study was to evaluate the efficacy of an Ovsynch protocol in the cyclic and non-cyclic Egyptian buffaloes in the summer. The present study was carried out on 21 Egyptian pluriparous buffalo cows (11 cyclic and 10 acyclic) and 8 heifers (5 cyclic and 3 acyclic). All animals were administered 100 microg GnRH i.m. at Day 0, 500 microg of PGF2 proportional, variant i.m. at Day 7 and a second dose (100 microg) of GnRH i.m. at Day 9. Ovarian structures of the animals were recorded by means of transrectal ultrasonography (6-8 MHz linear-array transducer) daily from Day 0 (before treatment) to Day 9 (the second GnRH administration) and thereafter, at 12-h interval till ovulation or for a maximum of 48 h. After ultrasound examination, a blood sample was taken daily from each animal for progesterone analysis. The buffalo cows were inseminated at 16-20 h after 2nd GnRH administration. After the first administration of GnRH, 46% (5 of 11) of cyclic and 50% (5 of 10) of acyclic cows and 40% (2 of 5) of cyclic and 33% (1 of 3) of acyclic heifers responded by ovulation or luteinization of the follicles. The mean diameters (+/-S.E.M.) of the follicles in the responding cows and heifers were significantly higher than those in non-responding animals (9.7 +/- 0.4 mm vs. 6.7 +/- 0.6 mm, P < 0.0001; 11.1 +/- 1.5 mm vs. 7.3 +/- 0.7 mm, P < 0.05, respectively). After the second administration of GnRH, 81% (9 of 11) of cyclic and 60% (6 of 10) of acyclic cows and 80% (4 of 5) of cyclic and 33% (1 of 3) of acyclic heifers ovulated, respectively. Ovulations occurred earlier (P = 0.059) and over a wider range of time in the non-cyclic cows (26 +/- 4.8 h; range: 12-36 h) and in a heifer (12 h,) than in the cyclic cows (34.7 +/- 1.3 h; range 24-36 h) and heifers (33 +/- 3 h; range: 24-36 h). The conception rate was 18% (2 of 11) and 0% (0 of 10) in cyclic and non-cyclic cows, respectively. In conclusion, the Ovsynch protocol could be used effectively for synchronization of ovulation in cyclic cows and heifers in summer.
本研究旨在评估 Ovsynch 方案在夏季埃及水牛中的周期性和非周期性发情牛中的功效。本研究在 21 头埃及经产水牛（11 头周期性和 10 头非周期性）和 8 头小母牛（5 头周期性和 3 头非周期性）中进行。所有动物均在第 0 天（治疗前）肌肉注射 100µg GnRH，第 7 天肌肉注射 500µg PGF2 比例可变，第 9 天肌肉注射第二次 100µg GnRH。从第 0 天（治疗前）到第 9 天（第二次 GnRH 给药）和此后，每隔 12 小时记录一次动物的卵巢结构，直至排卵或最长 48 小时。超声检查后，每天从每头动物采集血样进行孕激素分析。在第二次 GnRH 给药后 16-20 小时对水牛进行授精。在第一次 GnRH 给药后，46%（11 头中的 5 头）的周期性和 50%（10 头中的 5 头）的非周期性奶牛和 40%（5 头中的 2 头）的周期性和 33%（3 头中的 1 头）的非周期性小母牛通过排卵或卵泡黄体化反应。反应性奶牛和小母牛的卵泡平均直径（+/-SEM）明显高于非反应性动物（9.7 +/- 0.4 毫米对 6.7 +/- 0.6 毫米，P < 0.0001；11.1 +/- 1.5 毫米对 7.3 +/- 0.7 毫米，P < 0.05）。在第二次 GnRH 给药后，81%（11 头中的 9 头）的周期性和 60%（10 头中的 6 头）的非周期性奶牛和 80%（5 头中的 4 头）的周期性和 33%（3 头中的 1 头）的非周期性小母牛排卵。非周期性奶牛（26 +/- 4.8 小时；范围：12-36 小时）和小母牛（12 小时）的排卵时间更早（P = 0.059），时间范围更广，而周期性奶牛（34.7 +/- 1.3 小时；范围 24-36 小时）和小母牛（33 +/- 3 小时；范围 24-36 小时）的排卵时间则较晚。受孕率分别为 18%（11 头中的 2 头）和 0%（10 头中的 0 头）在周期性和非周期性奶牛中。总之，Ovsynch 方案可有效用于夏季周期性和非周期性发情牛的排卵同步化。
