King M E, McKelvey W A C, Dingwall W S, Matthews K P, Gebbie F E, Mylne M J A, Stewart E, Robinson J J
Scottish Agricultural College, Craibstone, Bucksburn, Aberdeen AB21 9YA, UK.
Theriogenology. 2004 Oct 1;62(7):1236-44. doi: 10.1016/j.theriogenology.2004.01.009.
Intrauterine insemination by laparoscopy is required to achieve acceptable lambing rates in ewes when using frozen semen but the procedure has evoked welfare concerns. Oxytocin has been used to dilate the cervix as a means of accessing the uterus during conventional cervical insemination, but its effect on fertility is not well documented. Three hundred crossbred ewes were synchronised in estrus and randomly allocated to one of three insemination procedures using frozen/thawed semen containing 400 x 10(6)/ml progressively motile sperm: single cervical (0.2 ml), multiple cervical (4 x 0.05 ml) or laparoscopic (0.05 ml per uterine horn). The effects of each insemination procedure on lambing rate (percentage of treated ewes lambing) and litter size (lambs per ewe lambing) were tested with and without oxytocin (10 IU given i.m.) prior to fixed-time insemination. Oxytocin did not permit complete cervical penetration in any ewes and neither lambing rate nor litter size was influenced by the number of inseminations. Lambing percentages were 69 and 42 (P < 0.01) for the laparoscopic and cervical insemination methods, respectively, and oxytocin reduced these to 58 (NS) and 10 (P < 0.001) percent, respectively. Corresponding litter sizes for ewes not receiving oxytocin were 1.91 and 1.51 and for those receiving oxytocin, 1.83 and 1.41 (laparoscopic versus cervical, P < 0.02). Thus, in the absence of complete cervical penetration at insemination, 10 IU oxytocin decreased the number of ewes lambing but had no effect on their litter size.
使用冷冻精液时，通过腹腔镜进行子宫内授精对于实现母羊可接受的产羔率是必需的，但该操作引发了对动物福利的担忧。在传统的宫颈授精过程中，催产素已被用于扩张子宫颈以进入子宫，但它对生育能力的影响尚未得到充分记录。300只杂交母羊进行了发情同步，然后随机分配到三种授精程序之一，使用含有400×10⁶/ml 进行性运动精子的冷冻/解冻精液：单次宫颈授精（0.2 ml）、多次宫颈授精（4×0.05 ml）或腹腔镜授精（每个子宫角0.05 ml）。在定时授精前，分别测试了有无催产素（肌肉注射10 IU）时，每种授精程序对产羔率（产羔母羊的百分比）和产仔数（每只产羔母羊的羔羊数）的影响。催产素未能使任何母羊完全穿透子宫颈，授精次数也不影响产羔率和产仔数。腹腔镜授精和宫颈授精方法的产羔百分比分别为69%和42%（P<0.01），催产素分别将其降至58%（无显著性差异）和10%（P<0.001）。未接受催产素的母羊相应产仔数为1.91和1.51，接受催产素的母羊为1.83和1.41（腹腔镜授精与宫颈授精相比，P<0.02）。因此，在授精时未完全穿透子宫颈的情况下，10 IU催产素减少了产羔母羊的数量，但对其产仔数没有影响。
