Department of Production Animal Health, University of Calgary Faculty of Veterinary Medicine, Calgary, AB, Canada.
Department of Large Animal Clinical Sciences, University of Saskatchewan, Western College of Veterinary Medicine, Saskatoon, SK, Canada.
J Anim Sci. 2019 Apr 29;97(5):1996-2008. doi: 10.1093/jas/skz094.
Assisted calves are often born weak, injured, or oxygen deprived and have a higher risk of morbidity and mortality. The objective was to investigate the impact of using pain mitigation at birth in assisted beef calves on physiological indicators of pain and inflammation, passive immunity, health, and growth. Thirty-three primiparous cows and their calves requiring assistance at birth on two ranches located in southern Alberta were enrolled. Data collected at birth include date and time of calving, calf sex, meconium staining, presentation of calf, and calving difficulty (easy assist: one person manually delivered the calf; difficult assist: delivery by two or more people, or mechanical assistance). Within 10 min of birth, calves were stratified by calving difficulty, randomized to a medication group, and received a subcutaneous dose of meloxicam (0.5 mg/kg BW) or an equivalent volume of placebo. Cow-calf pairs were then placed in individual box stalls for observation and sampling. At birth, 1, 4, and 24 h after birth, heart rate, respiratory rate, and rectal temperature were assessed and blood samples collected to measure indicators of pain and inflammation (cortisol, corticosterone, substance P, and haptoglobin). Serum IgG concentration and failed transfer of passive immunity (serum IgG concentration <24 g/L) were assessed in the 24-h blood samples. Preweaning treatment for disease and mortality information was collected and calves were weighed at 7 to 10 d of age and at weaning. Of the 33 calves enrolled, 17 calves received meloxicam and 16 calves received a placebo. Meloxicam-medicated calves had significantly greater ADG to 7 to 10 d of age (P = 0.05) (mean = 0.9 kg/d; SE = 0.10) compared with placebo-medicated calves (mean = 0.6 kg/d; SE = 0.12). There was no significant effect of meloxicam on physiological indicators of pain and inflammation, standing or nursing by 1 h, passive immunity, health outcomes, or ADG to weaning (P > 0.1). Although this was a small sample population, meloxicam given to assisted calves at birth improved ADG in the first week of life, which may indicate an important production management tool for improving well-being in assisted calves.
辅助分娩的犊牛通常出生时较弱、受伤或缺氧，发病率和死亡率较高。本研究旨在探讨在辅助分娩的肉牛犊牛出生时使用疼痛缓解措施对疼痛和炎症的生理指标、被动免疫、健康和生长的影响。在艾伯塔省南部的两个牧场，对 33 头初产奶牛及其在分娩时需要辅助的犊牛进行了研究。在分娩时收集的数据包括分娩日期和时间、犊牛性别、胎粪污染、犊牛姿势和分娩困难程度（容易辅助：一人手动助产；困难辅助：两人或多人助产，或使用机械辅助）。在出生后 10 分钟内，根据分娩困难程度将犊牛分为两组，随机分配到药物组，并接受皮下注射美洛昔康（0.5mg/kgBW）或等量的安慰剂。然后将牛犊放入单独的牛栏中进行观察和采样。在出生时、出生后 1、4 和 24 小时，评估心率、呼吸率和直肠温度，并采集血液样本以测量疼痛和炎症的指标（皮质醇、皮质酮、P 物质和结合珠蛋白）。在 24 小时的血液样本中评估血清 IgG 浓度和被动免疫转移失败（血清 IgG 浓度<24g/L）。收集了犊牛在 7 至 10 日龄和断奶前的疾病治疗和死亡率信息，并在 7 至 10 日龄和断奶时对犊牛进行称重。在纳入的 33 头犊牛中，17 头犊牛接受了美洛昔康治疗，16 头犊牛接受了安慰剂治疗。与接受安慰剂治疗的犊牛相比，接受美洛昔康治疗的犊牛在 7 至 10 日龄时的平均日增重（ADG）更高（P=0.05）（平均=0.9kg/d；SE=0.10），而接受安慰剂治疗的犊牛的平均日增重（ADG）更低（平均=0.6kg/d；SE=0.12）。美洛昔康对疼痛和炎症的生理指标、1 小时内的站立或哺乳、被动免疫、健康结果或断奶时的 ADG 没有显著影响（P>0.1）。尽管这是一个小样本人群，但在辅助分娩的犊牛出生时给予美洛昔康可提高其生命早期的 ADG，这可能表明这是改善辅助分娩犊牛福利的重要生产管理工具。
