McLean K J, Dahlen C R, Borowicz P P, Reynolds L P, Crosswhite M R, Neville B W, Walden S D, Caton J S
J Anim Sci. 2016 Dec;94(12):5089-5096. doi: 10.2527/jas.2016-0761.
We hypothesized that a standing flank ovariohysterectomy procedure could be developed in beef heifers that would provide high quality tissues for addressing critical questions during early pregnancy, while concomitantly keeping livestock stewardship a high priority. To test the hypothesis, we: 1) developed a standing flank ovariohysterectomy procedure for use in beef heifers, and 2) implemented this procedure in a cohort of heifers up to d 50 of pregnancy for tissue collections, documentation of post-surgical recovery, and assessment of feedlot finishing performance. Ovariectomy and cesarean section protocols are well established in research and veterinary medicine and were used as starting points for procedural development. Crossbred Angus heifers ( = 46; ∼ 15 mo of age; BW = 362.3 ± 34.7 kg) were used to develop this new surgical tissue collection technique. Heifers were subjected to the 5-d CO-Synch + CIDR estrous synchronization protocol so ovariohysterectomy occurred at d 16, 22, 28, 34, 40, and 50 of gestation. Key aspects of the standing flank ovariohysterectomy technique included 1) use of local anesthetic for a standing flank incision, 2) locate the uterine and ovarian arteries via blind palpation and ligate them through the broad ligament via an improved clinch knot, 3) cut the ovaries and uterus free from the broad ligament, 4) ligate the cervix and uterine branch of the vaginal artery, and 5) cut through the cervix and remove the reproductive tract. Surgical times, from skin incision to placement of the last suture, were influenced ( = 0.04) by stage of gestation. In pregnant heifers, time decreased from d 22 (120.0 ± 12.0 min) of gestation to d 40 (79.5 ± 12.0 min) of gestation; then increased at d 50 (90.5 ± 14.7 min) of gestation. Using this procedure, we obtained uterine, placental, and embryo/fetal tissues that had experienced limited hypoxia, little or no trauma, and thus were excellent quality for scientific study. All heifers recovered from surgery quickly and were moved to a finishing period. During the finishing period, ovariohysterectomized heifers had a DMI of 13.8 kg, gained 1.99 ± 0.35 kg/d, and had a G:F of 0.145 over 132-d. The standing flank ovariohysterectomy technique represents a new and viable model to economically obtain high quality tissues for investigating critical biological mechanisms during early pregnancy in beef heifers.
我们假设，可以为肉用小母牛开发一种站立式侧腹卵巢子宫切除术，该手术能提供高质量组织，用于解决早期妊娠期间的关键问题，同时将家畜管理放在高度优先的位置。为验证该假设，我们：1）开发了一种用于肉用小母牛的站立式侧腹卵巢子宫切除术；2）在一群妊娠至第50天的小母牛中实施该手术，以进行组织采集、记录术后恢复情况并评估饲养场育肥性能。卵巢切除术和剖宫产方案在研究和兽医学中已很成熟，被用作手术开发的起点。选用杂交安格斯小母牛（n = 46；约15月龄；体重 = 362.3±34.7千克）来开发这种新的手术组织采集技术。小母牛接受为期5天的CO-Synch + CIDR发情同步方案，以便在妊娠第16、22、28、34、40和50天进行卵巢子宫切除术。站立式侧腹卵巢子宫切除术技术的关键要点包括：1）在站立侧腹切口处使用局部麻醉；2）通过盲触诊定位子宫和卵巢动脉，并通过改良的紧结在阔韧带内结扎；3）将卵巢和子宫从阔韧带中游离出来；4）结扎阴道动脉的子宫分支和子宫颈；5）切开子宫颈并切除生殖道。从皮肤切口到最后一针缝合的手术时间受妊娠阶段影响（P = 0.04）。在妊娠小母牛中，时间从妊娠第22天（120.0±12.0分钟）降至第40天（79.5±12.0分钟）；然后在妊娠第50天（90.5±14.7分钟）增加。通过该手术，我们获得了经历有限缺氧、极少或无创伤的子宫、胎盘和胚胎/胎儿组织，因此是用于科学研究的优质组织。所有小母牛术后恢复迅速，并进入育肥期。在育肥期，接受卵巢子宫切除术的小母牛日均干物质摄入量为13.8千克，日增重1.99±0.35千克，在132天内的料重比为0.145。站立式侧腹卵巢子宫切除术技术代表了一种新的可行模型，可经济地获取高质量组织，用于研究肉用小母牛早期妊娠期间的关键生物学机制。
