Physiological stress responses have been associated with lesser pregnancy rates in beef cattle. Alternative cattle restraint methods have been developed to reduce this negative effect. The objective was to determine if there was a difference in pregnancy rate as a result of fixed-time artificial insemination (FTAI) in Bos taurus females when using a breeding box compared with a squeeze chute for restraining cows when conducting FTAI. There were FTAI treatment regimens imposed on cows and heifers at two separate locations (Virginia Tech University, VT; and R.A. Brown Ranch, RAB) with the FTAI being conducted while animals were restrained in a squeeze chute (n = 169) or a breeding box (n = 162). There was imposing of a 7-day Co-Sync + CIDR pre-breeding treatment regimen. Females were randomly assigned to treatments just prior to breeding. Immediately following breeding, blood was collected using coccygeal venipuncture procedures for assessment of plasma cortisol concentration. Chute and exit scores (1–5) were determined at the time of FTAI. Pregnancy rate, cortisol, chute score, and exit score were analyzed. There was no difference in pregnancy rate between treatments (57 ± 26% and 69 ± 26 %, respectively P = 0.59).There were differences in chute (1.52 ± 0.05 and 1.27 ± 0.05, respectively P < 0.05) and exit (1.26 ± 0.04 and 1.08 ± 0.04, respectively P < 0.05) scores between the two treatment groups. Results from the present study are not conclusive in ascertaining effects of the two types of restraint during FTAI on reproductive efficiency.

生理应激反应与肉牛较低的妊娠率有关。已经开发了替代的牛限制方法来减少这种负面影响。目的是确定在进行 FTAI时，与用于约束奶牛的挤压溜槽相比，使用育种箱时Bos taurus雌性的固定时间人工授精 (FTAI) 的妊娠率是否存在差异。在两个不同的地点（弗吉尼亚理工大学，VT 和 RA Brown Ranch，RAB）对奶牛和小母牛实施了 FTAI 治疗方案，在动物被限制在挤压槽（n = 169）或繁殖箱中时进行 FTAI ( n= 162）。实施了为期 7 天的 Co-Sync + CIDR 预育治疗方案。雌性在繁殖前被随机分配到治疗组。繁殖后立即使用尾骨静脉穿刺程序收集血液以评估血浆皮质醇浓度。滑槽和出口分数 (1-5) 在 FTAI 时确定。分析了妊娠率、皮质醇、滑道评分和退出评分。处理间妊娠率无差异（分别为 57±26% 和 69±26%，P =0.59）。斜槽（分别为 1.52±0.05 和 1.27±0.05，P <0.05）和退出（1.26±0.05）存在差异。 0.04 和 1.08 ± 0.04，分别为P< 0.05) 两个治疗组之间的评分。本研究的结果在确定 FTAI 期间两种类型的限制对繁殖效率的影响方面尚无定论。