Romano Juan E, Keisler Duane H, Amstalden Marcel
Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4475, USA.
Animal Science, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, MO, 65211-5300, USA.
Theriogenology. 2018 Nov;121:62-66. doi: 10.1016/j.theriogenology.2018.07.018. Epub 2018 Aug 9.
The objectives of this investigation were to determine the effect of copulation on estrus duration, LH response and ovulation in Boer goats. A controlled randomized study, with two replicates, in which does were divided at each replicate in treatment (COP; n = 12) and control (CON; n = 12) groups was performed. All the does were pluriparous and estrus synchronized with CIDR (progesterone 300 mg) maintained in the vagina for seven days, and received 50 μg of GnRH at device insertion and 5 mg of natural prostaglandin F-2 im at CIDR removal. The COP group received two copulas within the first 4 h of estrus onset, and the CON group was only permitted to be mounted. Estrus was detected twice a day during the first 24 h after pessary removal and then every 4 h by using bucks with canvas apron as teasers, led by leash for 96 h. Blood was collected during all the estrus period after each estrus detection and analyzed for LH by radioimmunoassay (RIA). In addition, at the second replicate ovulation time and number of ovulations were also monitored by transrectal ultrasonography using a linear 7.5 MHz probe beginning 24 h after estrus onset and repeated every 4 h until all the preovulatory follicles disappeared. Estrus onset was 36.7 ± 10.5 h and 35.5 ± 13.6 h for CON and COP groups, respectively (P = 0.82). Estrus duration for the same groups was 40.3 ± 9.9 h and 28.3 ± 4.7 h, respectively (P = 0.001). The LH peak time for the CON group was 17.7 ± 6.3 h, and for the COP group, it was 10.9 ± 2.6 h (P = 0.004). The LH peak magnitude for the same groups was 31.5 ± 16.2 ng/mL and 34.9 ± 20.7 ng/mL, respectively (P = 0.34). The LH peak duration was not different between groups (CON: 7.3 ± 1.6 h versus COP: 7.2 ± 2.4 h; P = 0.94). The first ovulation time for CON and COP groups was 33.7 ± 3.9 h and 29.1 ± 3.2 h (P = 0.05), and the last ovulation time for the same groups was 37.7 ± 3.9 h and 32.6 ± 2.5 h, respectively (P = 0.02). The overall time from LH peak to ovulation was 18.6 ± 4.8 h without differences between groups (CON: 16.3 ± 5.6 h versus COP: 20.6 ± 3.3 h; P = 0.15). The number of ovulations for the CON group was 2.2 ± 0.4, and for COP group, it was 2.1 ± 0.4 (P = 0.96). It was concluded that copulation reduced estrus duration and hastened LH peak and ovulation in Boer goats.
本研究的目的是确定交配对布尔山羊发情持续时间、促黄体生成素（LH）反应和排卵的影响。进行了一项有两个重复的对照随机研究，在每个重复中，将母羊分为处理组（COP；n = 12）和对照组（CON；n = 12）。所有母羊均为经产母羊，通过在阴道内放置含300 mg孕酮的阴道孕酮释放装置（CIDR）同步发情7天，并在放置装置时注射50 μg促性腺激素释放激素（GnRH），在取出CIDR时肌肉注射5 mg天然前列腺素F-2。COP组在发情开始后的前4小时内进行两次交配，CON组仅允许公羊爬跨。在取出阴道栓后的前24小时内每天检测两次发情，之后使用系着皮带的带帆布围裙的公羊作为诱情公羊每4小时检测一次发情，持续96小时。在每次发情检测后的整个发情期采集血液，通过放射免疫分析（RIA）测定LH。此外，在第二次重复实验中，从发情开始后24小时开始，使用线性7.5 MHz探头经直肠超声检查监测排卵时间和排卵数，每4小时重复一次，直到所有排卵前卵泡消失。CON组和COP组的发情开始时间分别为36.7±10.5小时和35.5±13.6小时（P = 0.82）。同一组的发情持续时间分别为40.3±9.9小时和28.3±4.7小时（P = 0.001）。CON组的LH峰值时间为17.7±6.3小时，COP组为10.9±2.6小时（P = 0.004）。同一组的LH峰值幅度分别为31.5±16.2 ng/mL和34.9±20.7 ng/mL（P = 0.34）。两组之间的LH峰值持续时间无差异（CON组：7.3±1.6小时 vs COP组：7.2±2.4小时；P = 0.94）。CON组和COP组的首次排卵时间分别为33.7±3.9小时和29.1±3.2小时（P = 0.05），同一组的末次排卵时间分别为37.7±3.9小时和32.6±2.5小时（P = 0.02）。从LH峰值到排卵的总时间为18.6±4.8小时，两组之间无差异（CON组：16.3±5.6小时 vs COP组：20.6±3.3小时；P = 0.15）。CON组的排卵数为2.2±0.4个，COP组为2.1±0.4个（P = 0.96）。得出的结论是，交配可缩短布尔山羊的发情持续时间，加速LH峰值出现和排卵。
