Department of Population Medicine, University of Guelph, Ontario, Canada N1G 2W1.
Department of Population Medicine, University of Guelph, Ontario, Canada N1G 2W1.
J Dairy Sci. 2018 Mar;101(3):2659-2668. doi: 10.3168/jds.2017-13581. Epub 2017 Dec 28.
The veal industry experiences calf losses during the growing period, which represents a challenge to animal welfare and profitability. Health status at arrival may be an important predictor of calf mortality. The objectives of this prospective cohort study were to describe the health status of calves arriving at a veal farm and determine the risk factors associated with early and late mortality. Using a standardized health scoring system, calves were evaluated immediately at arrival to a commercial milk-fed veal facility in Ontario, Canada. Weight at arrival and supplier of the calf were recorded. The calves were followed until death or the end of their production cycle. Two Cox proportional hazard models were built to explore factors associated with early (≤21 d following arrival) and late mortality (>21 d following arrival). A total of 4,825 calves were evaluated from November 2015 to September 2016. The overall mortality risk was 7%, with 42% of the deaths occurring in the first 21 d after arrival. An abnormal navel, dehydration, housing location within the farm, arriving in the summer, and the presence of a sunken flank were associated with increased hazard of early mortality. Drover-derived calves and calves with a greater body weight at arrival had lower hazard of early mortality. Housing location within the farm, being derived from auction facilities, and an abnormal navel were associated with higher hazard of late mortality. These results demonstrate that risk factors for mortality can be identified at arrival, which represents a potential opportunity to selectively intervene on these calves to reduce mortality. However, methods of preventing the development of these conditions before arrival need to be explored and encouraged to improve the welfare of the calves entering the veal industry.
在育肥期,小牛肉行业会经历小牛死亡,这对动物福利和盈利能力构成挑战。到达时的健康状况可能是预测小牛死亡率的重要指标。本前瞻性队列研究的目的是描述到达小牛肉农场的小牛的健康状况,并确定与早期和晚期死亡相关的风险因素。使用标准化健康评分系统,在加拿大安大略省的一家商业牛奶育肥设施,对小牛到达时立即进行评估。记录到达时的体重和小牛的供应商。对小牛进行跟踪,直到死亡或生产周期结束。建立了两个 Cox 比例风险模型来探讨与早期(到达后≤21 天)和晚期死亡率(到达后>21 天)相关的因素。2015 年 11 月至 2016 年 9 月,共评估了 4825 头小牛。总体死亡率风险为 7%,其中 42%的死亡发生在到达后 21 天内。脐部异常、脱水、农场内的住房位置、夏季到达以及凹陷的肋部与早期死亡的风险增加相关。来自赶牛者的小牛和到达时体重较大的小牛,早期死亡的风险较低。农场内的住房位置、来自拍卖设施以及脐部异常与晚期死亡的风险增加相关。这些结果表明,在到达时可以识别出与死亡率相关的风险因素,这代表了有潜力对这些小牛进行有针对性的干预,以降低死亡率。然而,需要探索并鼓励在到达前采取措施防止这些情况的发生,以提高进入小牛肉行业的小牛的福利。