Roper David A, Schrick F Neal, Edwards J Lannett, Hopkins Fred M, Prado Tulio M, Wilkerson John B, Saxton Arnold M, Young Charles D, Smith W Brandon
Tarleton State University Department of Animal Science and Veterinary Technology, 1333 West Washington, Stephenville, TX 76402, USA; University of Tennessee Animal Science Department, 2506 River Dr., Knoxville, TN 37996, USA.
University of Tennessee Animal Science Department, 2506 River Dr., Knoxville, TN 37996, USA.
Anim Reprod Sci. 2018 Dec;199:79-83. doi: 10.1016/j.anireprosci.2018.11.001. Epub 2018 Nov 6.
The use of embryo transfer (ET) in cattle is important for profitability and improved genetic gains. The advent of the commercial embryo collection and transfer industry has led to advancements in multiple techniques and practices. Specific variables, however, have historically affected pregnancy rates but an understanding of the magnitude of these effects in the current industry is limited. Transfer location (cranial, middle, or caudal third of the uterine horn ipsilateral to the ovary with a CL), transfer score (range of 1-3 with 1 being excellent and 3 poor, based on difficulty of accessing the site of embryo deposition), and amount of time to complete a transfer, therefore, were recorded. These variables were collected in a setting designed to mimic commercial production practices as well as exaggerated time (due to data collection) to assess effects on pregnancy rates. Fresh and frozen in vivo-derived embryos (n = 256) from Bos taurus cows were transferred to Bos taurus recipients. There tended to be more pregnancies when embryos were deposited in the cranial part of the uterus (P = 0.08) compared to the middle and caudal third of the uterus. With a lesser degree of difficulty in transfers (score 1), there tended to be more pregnancies established (P = 0.07). When lesser time was needed for transferring embryos and collecting data, there were greater pregnancy rates (P = 0.03). Thus, these traditionally accepted variables of influence (site of embryo placement in uterus, difficulty, and time) continue to influence ET pregnancy success.
在奶牛中使用胚胎移植（ET）对于提高盈利能力和增加遗传增益非常重要。商业胚胎采集和移植行业的出现推动了多种技术和实践的进步。然而，特定变量在历史上一直影响着妊娠率，但目前行业中对这些影响程度的了解有限。因此，记录了移植位置（与有黄体的卵巢同侧子宫角的头三分之一、中三分之一或尾三分之一）、移植评分（范围为1 - 3，1表示优秀，3表示差，基于胚胎植入部位的难易程度）以及完成一次移植所需的时间。这些变量是在一个旨在模拟商业生产实践以及延长时间（由于数据收集）的环境中收集的，以评估对妊娠率的影响。将来自荷斯坦奶牛的新鲜和冷冻体内衍生胚胎（n = 256）移植到荷斯坦受体母牛体内。与子宫的中三分之一和尾三分之一相比，当胚胎植入子宫头部时，妊娠的情况往往更多（P = 0.08）。移植难度较小（评分为1）时，妊娠的情况往往更多（P = 0.07）。当移植胚胎和收集数据所需时间较少时，妊娠率更高（P = 0.03）。因此，这些传统上公认的影响变量（胚胎在子宫内的植入部位、难度和时间）继续影响胚胎移植的妊娠成功率。
