摘要
The experiments described examined the effects of a number of factors on the level of uterine insemination achieved in Merino ewes by a transcervical insemination technique (Guelph system for transcervical artificial insemination; GST-AI). Cervical penetration rate is an important limitation to the use of such methods in Merinos. Simulated insemination was performed to estimate the proportion of ewes in which a pipette could be passed through the cervix to the uterus.
In Experiment 1, cervical penetration rate (n = 14 to 30)was unaffected by an increase in postpartum interval at AI from 12 to 26 wk. The results of cervical penetration for individual ewes were found to be repeatable (P < 0.05).
Experiment 2 (197 ewes) revealed a clear effect of ewe parity on penetration rates in hormonally synchronized ewes during the nonbreeding season (P < 0.05).
In Experiment 3, estrus synchronization using progestagen (n = 51) or prostaglandin (n = 50) did not affect penetration rate. The penetration rate was slightly higher in the naturally cycling ewes, but the difference was not significant. Comparison of ewes from Experiments 2 and 3 suggests the possibility of a major effect of stage of the breeding season on the penetration rate (P < 0.05).
It is concluded that ewe selection and management techniques may be used to increase the proportion of transcervical insemination attempts resulting in uterine insemination. However, fertility testing will be required to determine whether such improvements translate into correspondingly increased pregnancy rates.
摘要译文
采用经宫颈人工授精技术（Guelph系统进行经宫颈人工授精，在美利奴羊中实现的子宫授精水平的多种因素的影响;GST-AI）。宫颈渗透率是在美利奴斯州使用这种方法的一个重要限制。[模拟人工授精是为了估计移液管可以通过子宫颈到达子宫的比例。在实验1中，宫颈渗透率（n \x3d 14至30）不受AI后产后间隔12至26周的增加影响。发现个体母羊的宫颈渗透结果是可重复的（P 0.05）。[实验二（197只母羊））显示，在非同期繁殖的母羊中，母羊产奶量对母羊穿透率有明显的影响（P 0.05）。在实验三中，使用孕激素（n \x3d 51）或前列腺素（n \x3d 50）的发情同步不影响渗透率。自然循环母羊的穿透率略高，但差异并不显着。实验2和3的母羊的比较表明繁殖季节的阶段对渗透率有重大影响的可能性（P 0.05）。结论是母羊的选择和管理技术可以用来增加经宫颈人工授精的比例，导致子宫授精。然而，将需要生育力测试来确定这样的改善是否相应地提高了怀孕率。
D.P. Windsor. Factors influencing the success of transcervical insemination in Merino ewes[J]. Theriogenology, 1995,43(6): 1009-1018