Ali A, Hayder M, Saifelnaser E O H
Department of Theriogenology, Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt.
Reprod Domest Anim. 2009 Dec;44(6):873-8. doi: 10.1111/j.1439-0531.2008.01102.x.
This study aimed to evaluate three regimes for oestrus and ovulation synchronization in Farafra ewes in the subtropics. During autumn, 43 ewes were assigned to (i) controlled internal drug releasing (CIDR)-eCG group, treated with CIDR for 12 days and eCG at insert withdrawal, n=13; (ii) PGF2alpha-PGF2alpha group, treated with two PGF2alpha injections at 11 days interval, n=14; and (iii) GnRH-PGF2alpha-GnRH group, treated with GnRH, followed 5 days later with PGF2alpha and 24 h later with a second GnRH, n=16. Oestrus-mating detection was carried out at 4 h intervals starting on day 0 [the day of CIDR withdrawal (CIDR-eCG group), the day of second PGF2alpha treatment (PGF2alpha-PGF2alpha group) and the day of PGF2alpha treatment (GnRH-PGF2alpha-GnRH group)]. Ovarian dynamics was monitored by ultrasound every 12 h beginning on day 0 and continued for 4 days. Blood samples were obtained daily for progesterone (P4) and oestradiol 17beta (E2) estimation starting on day 0 and continued for 4 days. The obtained results showed that, oestrus expression, ovulation and conception were greater (p<0.05) in CIDR-eCG and PGF2alpha-PGF2alpha groups than in GnRH-PGF2alpha-GnRH group. All ewes of PGF2alpha-PGF2alpha group presented, on day of second PGF2alpha injection with mature CL (P4>2.0 ng/ml), compared to 42.9% in GnRH-PGF2alpha-GnRH group (p=0.01). The peak of oestrus occurred 32-52, 48-60 and 28-96 h after the end of treatment in CIDR-eCG, PGF2alpha-PGF2alpha and GnRH-PGF2alpha-GnRH groups, respectively. Ovulation started 48 h after treatment in all groups and extended for 24, 36 and 48 h for CIDR-eCG, PGF2alpha-PGF2alpha and GnRH-PGF2alpha-GnRH groups, respectively. Results demonstrated that oestrus and ovulation synchronization could be efficiently achieved in Farafra ewes using either CIDR-eCG or PGF2alpha-PGF2alpha regimes; however, the GnRH-PGF2alpha-GnRH treatment induced a more spread oestrus and ovulation that may make the protocol inadequate for timed artificial insemination.
本研究旨在评估亚热带法拉夫拉母羊发情和排卵同步的三种方案。秋季期间，43只母羊被分配到：（i）控制内部药物释放（CIDR）-eCG组，用CIDR处理12天，并在取出插入物时注射eCG，n = 13；（ii）PGF2α-PGF2α组，每隔11天注射两次PGF2α，n = 14；以及（iii）GnRH-PGF2α-GnRH组，先注射GnRH，5天后注射PGF2α，24小时后再注射第二次GnRH，n = 16。从第0天开始每隔4小时进行一次发情交配检测[CIDR取出日（CIDR-eCG组）、第二次PGF2α处理日（PGF2α-PGF2α组）和PGF2α处理日（GnRH-PGF2α-GnRH组）]。从第0天开始每隔12小时通过超声监测卵巢动态，并持续4天。从第0天开始每天采集血样用于孕酮（P4）和雌二醇17β（E2）测定，并持续4天。所得结果表明，CIDR-eCG组和PGF2α-PGF2α组的发情表现、排卵和受孕情况均高于（p<0.05）GnRH-PGF2α-GnRH组。PGF2α-PGF2α组的所有母羊在第二次注射PGF2α日出现成熟黄体（P4>2.0 ng/ml），而GnRH-PGF2α-GnRH组为42.9%（p = 0.01）。CIDR-eCG组、PGF2α-PGF2α组和GnRH-PGF2α-GnRH组发情高峰分别出现在治疗结束后32 - 52小时、48 - 60小时和28 - 96小时。所有组排卵均在治疗后48小时开始，CIDR-eCG组、PGF2α-PGF2α组和GnRH-PGF2α-GnRH组分别持续24小时、36小时和48小时。结果表明，使用CIDR-eCG或PGF2α-PGF2α方案可有效实现法拉夫拉母羊的发情和排卵同步；然而，GnRH-PGF2α-GnRH处理诱导的发情和排卵更为分散，这可能使该方案不适用于定时人工授精。
