MSD Animal Health Innovation, Angers Technopole, Beaucouzé, France.
Theriogenology. 2013 Sep 1;80(4):391-9. doi: 10.1016/j.theriogenology.2013.05.002. Epub 2013 Jun 15.
The aim of this study was to demonstrate successful breeding of sows with a single fixed-time insemination following ovulation induction by buserelin, a GnRH analogue. In a first step, the optimal dose of buserelin (6, 10, or 16 μg) injected at 77 hours after weaning was determined in weaned sows (N = 15, 11, and 12, respectively) using its ability to induce an LH surge of similar magnitude as in control sows (N = 15) and induce ovulation. In 29/38 treated sows (76%), ovulation was induced and synchronized between 32 and 44 hours after injection, and the proportion of females ovulating during this time window was similar between groups at 73%, 73%, and 83% (6, 10, or 16 μg, respectively). Interestingly, whereas ovulation of 100% multiparous sows was induced and synchronized in the 32 to 44 hours posttreatment time window, successful induction was achieved in a lower proportion of primiparous sows (50%, 50%, and 67% following 6, 10, or 16 μg, respectively), the dose effect being nonsignificant. The magnitude of the LH surge was similar between control and treated sows, irrespective of the buserelin dose injected. Neither ovulation rate nor the number of good embryos on Day 5 postovulation differed between groups. Interestingly, the frequency of follicular cysts at slaughter was significantly affected by treatment (P < 0.05), being minimal and maximal in sows treated with 10 or 6 μg buserelin, respectively. In a second step, 419 sows from commercial herds in Spain, Germany, and France were randomly allocated to a control or treated group. The control sows were inseminated twice 12 ± 4 hours apart once estrus was detected. Treated sows received 10 μg buserelin at 86 ± 3 hours after weaning and were inseminated once 30 to 33 hours later. Farrowing rate of treated sows (87%, 166/192) was similar to that of control sows (84.5%, 169/200). Litter size was also similar between treated and control sows (13.6 ± 3.8 vs. 13.7 ± 3.2). In multiparous sows, neither duration of lactation nor magnitude of the fat loss during lactation significantly affected treatment effects. It is concluded that ovulation of weaned multiparous sows can be tightly synchronized by buserelin (10 μg) administration at 86 hours postweaning. This allows breeding once at a fixed time following buserelin injection while maintaining reproductive performance at a level similar to that of sows bred twice during estrus.
本研究旨在展示通过 GnRH 类似物布舍瑞林诱导排卵后，母猪单次定时输精配种的成功繁殖。在断奶母猪（N=15、11 和 12）中，首先确定了布舍瑞林（6、10 或 16μg）在断奶后 77 小时注射的最佳剂量，其作用是诱导与对照组母猪（N=15）相似的 LH 峰，并诱导排卵。在 38 头治疗母猪中（76%），有 29 头（6、10 或 16μg 组）成功诱导并同步排卵，排卵发生在注射后 32 至 44 小时之间，在此时间窗口内排卵的雌性比例在各组间相似，分别为 73%、73%和 83%。有趣的是，虽然 100%的经产母猪在 32 至 44 小时的治疗后成功诱导并同步排卵，但初产母猪的成功诱导比例较低（6、10 或 16μg 组分别为 50%、50%和 67%），剂量效应无显著差异。无论注射的布舍瑞林剂量如何，对照组和治疗组母猪的 LH 峰幅度相似。排卵率和排卵后第 5 天的优质胚胎数量在各组间无差异。有趣的是，卵巢滤泡囊肿的频率受处理的影响（P<0.05），在接受 10 或 6μg 布舍瑞林治疗的母猪中，卵巢滤泡囊肿的频率最低和最高。在第二步中，来自西班牙、德国和法国商业猪场的 419 头母猪被随机分配到对照组或治疗组。对照组母猪在发情时，两次定时输精，间隔 12±4 小时。治疗组母猪在断奶后 86±3 小时接受 10μg 布舍瑞林，30 至 33 小时后进行一次输精。治疗组母猪的产仔率（87%，166/192）与对照组母猪（84.5%，169/200）相似。处理组和对照组母猪的窝产仔数也相似（13.6±3.8 与 13.7±3.2）。在经产母猪中，哺乳期长短和哺乳期体脂损失大小均不显著影响处理效果。研究结论为，通过在断奶后 86 小时注射 10μg 布舍瑞林，可使断奶经产母猪的排卵同步化。这允许在注射布舍瑞林后，母猪在固定时间配种一次，同时保持与发情期配种两次的母猪相似的繁殖性能。
