Pearson Jennifer M, Homerosky Elizabeth R, Caulkett Nigel A, Campbell John R, Levy Michel, Pajor Edmond A, Windeyer M Claire
Department of Production Animal Health, University of Calgary Faculty of Veterinary Medicine, Calgary, Alberta, Canada.
Veterinary Agri-Health Services Ltd., Airdrie, Alberta, Canada.
Vet Rec Open. 2019 Jan 25;6(1):e000325. doi: 10.1136/vetreco-2018-000325. eCollection 2019.
This cross-sectional study quantifies subclinical trauma associated with calving difficulty, calf vigour, and passive immunity (PI) in newborn beef calves. The degree of calving difficulty was categorised as: unassisted, easy assist (one or two people manually pulling to deliver the calf) and difficult assist (more than two people pulling, a fetal extractor (ie, calf jack), or caesarean section). Vigour assessment occurred at 10 minutes and blood sampling at 24 hours after birth in 77 beef calves. The measured blood parameters associated with trauma were creatine kinase (CK), aspartate aminotransferase (AST), and haptoglobin. Serum IgG concentration was measured, and an IgG concentration at least 24 g/l was considered as adequate PI. Calving difficulty was associated with elevated levels of CK (P=0.002) and AST (P=0.01), weak suckle reflex (P=0.001), abnormal mucous membrane colour (P<0.0001), and decreased odds of adequate PI (P=0.004). Elevated levels of CK and AST were associated with abnormal mucous membrane colour, incomplete tongue withdrawal and weak suckle reflex at birth (P<0.001). An incomplete tongue withdrawal (P=0.005) and weak suckle reflex (P=0.02) were associated with decreased IgG concentrations. Abnormal mucous membrane colour, incomplete tongue withdrawal, and a weak suckle reflex were associated with decreased odds of having adequate PI (P<0.05). Haptoglobin was not associated with any of the parameters measured. Subclinical trauma was associated with calving difficulty, decreased vigour and decreased odds of having adequate PI. Understanding the impacts of a traumatic birth may aid the development of management strategies for compromised newborn beef calves.
这项横断面研究对新生肉用犊牛中与产犊困难、犊牛活力和被动免疫（PI）相关的亚临床创伤进行了量化。产犊困难程度分为：无辅助、轻松辅助（一两个人手动牵拉以产出犊牛）和困难辅助（超过两个人牵拉、使用胎儿提取器（即犊牛助产器）或剖宫产）。对77头肉用犊牛在出生后10分钟进行活力评估，并在出生后24小时进行采血。与创伤相关的测量血液参数有肌酸激酶（CK）、天冬氨酸转氨酶（AST）和触珠蛋白。测量血清IgG浓度，IgG浓度至少24 g/l被认为是足够的被动免疫。产犊困难与CK水平升高（P=0.002）、AST水平升高（P=0.01）、弱吸吮反射（P=0.001）、黏膜颜色异常（P<0.0001）以及足够被动免疫几率降低（P=0.004）相关。CK和AST水平升高与出生时黏膜颜色异常、舌头回缩不完全和弱吸吮反射相关（P<0.001）。舌头回缩不完全（P=0.005）和弱吸吮反射（P=0.02）与IgG浓度降低相关。黏膜颜色异常、舌头回缩不完全和弱吸吮反射与有足够被动免疫的几率降低相关（P<0.05）。触珠蛋白与所测量的任何参数均无关。亚临床创伤与产犊困难、活力降低和有足够被动免疫的几率降低相关。了解创伤性分娩的影响可能有助于制定针对受损新生肉用犊牛的管理策略。
