Department of Population Medicine, University of Guelph, Guelph, ON, N1G 2W1 Canada.
Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1 Canada.
J Dairy Sci. 2024 Sep;107(9):7267-7275. doi: 10.3168/jds.2023-24525. Epub 2024 May 23.
The welfare of cull cows during transport to slaughter is a current concern in the Canadian dairy industry. Cull cows sold through auction often have a high prevalence of lameness, low BCS, hock lesions, and udder engorgement. To evaluate whether drying off and feeding cull dairy cows before transport can mitigate these challenges, 45 cows designated for culling were randomly assigned to either be fed for 60 d after being dried off (fed group; n = 24) or to serve as controls by being sent directly to slaughter (direct group; n = 21). Two fed group cows were removed for health reasons before completing the feeding period. Both fed group and direct group cows were assessed for locomotion (5-point scale), BCS (5-point scale), hock lesions (3-point scale), udder engorgement (3-point scale), and BW at the time of enrollment. Fed group cows, locomotion, BCS, hock, and udder engorgement scores were assessed weekly until slaughter. Weights of the fed group cows were measured again the day before slaughter. Mixed linear regression models were used to assess continuous outcomes BCS and weight. Mixed logistic regression models were used to assess dichotomous outcomes presence of hock lesions and lameness. Fed group cows gained an average of 116.9 kg over the feeding period (SE ± 8.20). Fed group cows had an average weight at slaughter of 834.2 kg, whereas direct group cows' average weight was 767.3 kg (SE ± 26.8). The fed group cows' average BCS at the start of the trial was 2.4, and at slaughter was 3.6, with an average gain of 1.2 BCS points. At slaughter, the proportion of udders involuted in the fed group was 45.1% (10/22) and in the direct group cows, was 0% (0/21). No differences were found in locomotion or hock lesions between the fed group and direct groups. It is important to weigh potential benefits for the fed group cows with the fact that direct group cows did not endure a drying off procedure, nor were they placed at risk of potential adverse health events. However, despite these potential limitations, due to the improved BCS and udder engorgement scores, cows fed for 60 d may be better prepared for the transportation to slaughter, as well as sell for a higher price due to increased BW and body condition.
在运往屠宰场的过程中，淘汰奶牛的福利是加拿大奶牛养殖业目前关注的一个问题。通过拍卖出售的淘汰奶牛往往跛行发生率高、体况评分（BCS）低、跗关节病变和乳房肿胀。为了评估在运输前使淘汰奶牛干奶并进行饲养是否可以减轻这些挑战，将 45 头被指定淘汰的奶牛随机分为干奶后饲养 60 天组（n = 24）或直接运往屠宰组（n = 21）。由于健康原因，有 2 头饲养组奶牛在完成饲养期之前被移除。在入组时对饲养组和直接组奶牛进行运动能力（5 分制）、BCS（5 分制）、跗关节病变（3 分制）、乳房肿胀（3 分制）和体重评估。饲养组奶牛在饲养期间每周进行运动能力、BCS、跗关节和乳房肿胀评估，直到屠宰。在屠宰前一天再次测量饲养组奶牛的体重。使用混合线性回归模型评估 BCS 和体重等连续结果。使用混合逻辑回归模型评估跗关节病变和跛行的二分结果。饲养组奶牛在饲养期间平均增重 116.9kg（SE ± 8.20）。饲养组奶牛的屠宰体重平均为 834.2kg，而直接组奶牛的平均体重为 767.3kg（SE ± 26.8）。饲养组奶牛试验开始时的平均 BCS 为 2.4，屠宰时为 3.6，平均增加 1.2 BCS 点。在屠宰时，饲养组奶牛乳房萎缩的比例为 45.1%（10/22），而直接组奶牛为 0%（0/21）。饲养组和直接组奶牛在运动能力或跗关节病变方面没有差异。需要权衡饲养组奶牛的潜在益处，因为直接组奶牛没有经历干奶过程，也没有面临潜在的健康不良事件的风险。然而，尽管存在这些潜在的局限性，但由于 BCS 和乳房肿胀评分的提高，饲养 60 天的奶牛可能在运输到屠宰场时准备得更好，并且由于体重和体况增加，销售价格更高。
