Animal Welfare Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, V6T 1Z4, Canada.
Animal Welfare Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, V6T 1Z4, Canada.
J Dairy Sci. 2020 Mar;103(3):2636-2649. doi: 10.3168/jds.2019-17435. Epub 2020 Jan 15.
Many cows culled from dairy farms arrive at livestock markets or abattoirs in compromised condition, but it is unknown whether cows are compromised at the time of culling or deteriorate during the marketing process. This study followed cull cows from farm to abattoir, monitored any deterioration, and tested the effect of providing such information on subsequent culling. For 11 mo, data were collected from 20 dairy farms, livestock markets, and abattoirs. Cows' body condition, lameness, and udder condition (as binary outcomes) were assessed at 4 points: when placed on the culling list, before leaving the farm, at auction, and at the abattoir. Based on the first 5 mo of data (baseline period), information materials were provided to 10 randomly selected farms (Informed treatment), and the other 10 served as a Control. Logistic mixed models were used to test differences in cows' condition at the 4 points of assessment, using the assessment before leaving the farm as a reference value and cow-within-farm as a random effect. The effects of providing information on outcome measures (proportion thin, severely lame, with udder edema, poor fitness for transport, euthanized, and died) were tested with a general linear model. As demand for milk increased during the baseline period, additional linear mixed models were fitted to test whether the same outcome measures were affected by time (baseline or treatment period) and treatment (Informed or Control) using farm as a random effect. While cows were on the culling list (before shipping) the odds of being thin or having poor fitness for transport increased. After leaving the farms, cows spent (mean ± standard deviation) 82 ± 46 h in the marketing system before being slaughtered. Shipping from farm to abattoir increased the odds of being thin, having udder edema, or showing poor fitness for transport [odds ratio (OR) 5.8, 95% confidence interval 4.2 to 8.1; OR 14.7, 10.7 to 20.2; and OR 7.3, 5.7 to 9.5, respectively]. Providing this information to farmers (Informed treatment) did not affect the outcome measures. Compared with the baseline, during the treatment period fewer cows were shipped when thin (4.9 versus 9.0%) and with poor fitness for transport (15.7 versus 25.8%), and fewer cows died (5.4 versus 11.9%) or were euthanized (13.3 versus 20.5%). Increased demand for milk appeared to lead to delayed culling, such that more compromised cows were sent to slaughter. The results of this study show a need for clear and specific guidelines to assess fitness for transport of cull dairy cows.
许多从奶牛场淘汰的奶牛在到达牲畜市场或屠宰场时身体状况不佳，但目前尚不清楚奶牛是在淘汰时身体状况不佳，还是在销售过程中恶化。本研究从农场到屠宰场跟踪淘汰奶牛，监测任何恶化情况，并测试提供此类信息对后续淘汰的影响。在 11 个月的时间里，数据从 20 个奶牛场、牲畜市场和屠宰场收集。在 4 个时间点评估奶牛的身体状况、跛行和乳房状况（作为二项结果）：列入淘汰名单时、离开农场前、在拍卖场和在屠宰场。根据前 5 个月的数据（基线期），向 10 个随机选择的农场（知情治疗）提供信息材料，其余 10 个作为对照。使用离开农场前的评估作为参考值和牛内场作为随机效应，使用逻辑混合模型测试 4 个评估点奶牛状况的差异。使用一般线性模型测试提供信息对结果测量（瘦的比例、严重跛行、乳房水肿、运输不适、安乐死和死亡）的影响。随着基线期牛奶需求的增加，还拟合了额外的线性混合模型，以使用农场作为随机效应，测试相同的结果测量是否受到时间（基线或治疗期）和治疗（知情或对照）的影响。当奶牛列入淘汰名单（在运输前）时，瘦弱或运输不适的可能性增加。离开农场后，奶牛在被屠宰前在销售系统中平均（平均值±标准差）停留 82±46 小时。从农场运到屠宰场增加了瘦弱、乳房水肿或运输不适的可能性[比值比（OR）5.8，95%置信区间 4.2 至 8.1；OR 14.7，10.7 至 20.2；OR 7.3，5.7 至 9.5]。向农民提供此信息（知情治疗）并未影响结果测量。与基线相比，在治疗期间，瘦弱（4.9%比 9.0%）和运输不适（15.7%比 25.8%）的奶牛数量减少，死亡（5.4%比 11.9%）或安乐死（13.3%比 20.5%）的奶牛数量减少。对牛奶的需求增加似乎导致淘汰时间延迟，从而使更多身体状况不佳的奶牛被送往屠宰场。本研究结果表明，需要制定明确和具体的指南来评估淘汰奶牛的运输适应性。
