Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, T1J 4B1 AB, Canada.
J Anim Sci. 2012 Oct;90(10):3630-9. doi: 10.2527/jas.2011-4786. Epub 2012 Jun 4.
The objective of the present study was to identify and quantify several factors affecting shrink in cattle during commercial long-haul transport (≥400 km; n = 6,152 journeys). Surveys were designed and delivered to transport carriers to collect relevant information regarding the characteristics of animals, time of loading, origin and destination, and loaded weight before and after transport. In contrast to fat cattle, feeder cattle exhibited greater shrink (4.9 vs. 7.9 ± 0.2% of BW, respectively; P < 0.01), and experienced longer total transport durations (12.4 vs. 14.9 ± 0.99, respectively; P < 0.01) due to border crossing protocols which require mandatory animal inspection. Shrink was greater (P < 0.001) for feeder cattle loaded at ranches/farms and feed yards compared with those loaded at auction markets. Cattle loaded during the afternoon and evening shrank more than those loaded during the night and morning (P < 0.05). Shrinkage was less in cattle transported by truck drivers having 6 or more years of experience hauling livestock compared with those with 5 yr or less (P < 0.05). Shrink increased with both midpoint ambient temperature (% of BW/°C; P < 0.001) and time on truck (% of BW/h; P < 0.001). Temperature and time on truck had a multiplicative effect on each other because shrink increased most rapidly in cattle transported for both longer durations and at higher ambient temperatures (P < 0.001). The rate of shrink over time (% of BW/h) was greatest in cull cattle, intermediate in calves and feeder cattle, and slowest in fat cattle (P < 0.05) but such differences disappeared when the effects of place of origin, loading time, and experience of truck drivers were included in the model. Cull cattle, calves and feeder cattle appear to be more affected by transport compared with fat cattle going to slaughter because of greater shrink. Several factors should be considered when developing guidelines to reduce cattle transport stress and shrink including type of cattle, ambient temperature, transport duration, driving quality, and time and origin of loading.
本研究的目的是确定和量化影响商业长途运输（≥400 公里；n=6152 次运输）中牛体重减轻的几个因素。设计并向运输商发送了调查，以收集有关动物特征、装载时间、起点和终点以及运输前后装载重量的相关信息。与肥牛相比，育肥牛的体重减轻更大（分别为 4.9%和 7.9%±0.2%的 BW；P<0.01），并且由于边境过境协议需要强制性的动物检查，总运输时间更长（分别为 12.4%和 14.9%±0.99；P<0.01）。与从牧场/农场和饲料场装载的育肥牛相比，在拍卖市场装载的育肥牛体重减轻更大（P<0.001）。下午和晚上装载的牛比夜间和清晨装载的牛体重减轻更多（P<0.05）。有 6 年或以上牲畜运输经验的卡车司机运输的牛体重减轻比有 5 年或以下经验的司机运输的牛体重减轻少（P<0.05）。体重减轻与环境温度中点（%BW/°C；P<0.001）和卡车时间（%BW/h；P<0.001）成正比。温度和卡车时间相互产生乘法效应，因为在较长时间和较高环境温度下运输的牛体重减轻最快（P<0.001）。随着时间的推移（%BW/h）的体重减轻率在淘汰牛中最大，在犊牛和育肥牛中中等，在肥牛中最慢（P<0.05），但当将原产地、装载时间和卡车司机经验的影响纳入模型时，这些差异就消失了。与运往屠宰场的肥牛相比，淘汰牛、犊牛和育肥牛似乎更容易受到运输的影响，因为它们的体重减轻更大。在制定减少牛运输应激和体重减轻的指导方针时，应考虑几个因素，包括牛的类型、环境温度、运输持续时间、驾驶质量以及装载的时间和地点。
