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Les veaux et les bovins de réforme étaient les plus susceptibles de mourir ou de devenir non ambulants durant le transport; les animaux d’engraissement venaient ensuite, les animaux finis semblant être les plus aptes à composer avec le stress du transport (P ≤ 0,01). La probabilité qu’un bovin devienne non ambulant, boite ou meure montait en flèche après que les animaux avaient passé plus de 30 h dans la remorque (P < 0,001).
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The objective of the present study was to document the relationships between selected welfare outcomes and transport conditions during commercial long haul transport of cattle (≥ 400 km; 6,152 journeys; 290,866 animals). Surveys were delivered to transport carriers to collect information related to welfare outcomes including the number of dead, non-ambulatory (downer) and lame animals during each journey. Transport conditions surveyed included the length of time animals spent on truck, ambient temperature, animal density, shrinkage, loading time, cattle origin, season, experience of truck drivers, and vehicle characteristics. Overall 0.012% of assessed animals became lame, 0.022% non-ambulatory and 0.011% died on-board. Calves and cull cattle were more likely to die and become non-ambulatory during the journey, feeders intermediate, and fat cattle appeared to be the most able to cope with the stress of transport (P ≤ 0.01). The likelihood of cattle becoming non-ambulatory, lame, or dead increased sharply after animals spent over 30 h on truck (P < 0.001). The likelihood of animal death increased sharply when the midpoint ambient temperature fell below -15 ºC (P = 0.01) while the likelihood of becoming non-ambulatory increased when temperatures rose above 30 ºC (P = 0.03). Animals that lost 10% of their body weight (BW) during transport had a (P < 0.001) greater likelihood of dying and becoming non-ambulatory or lame. Animals were more likely to die at lower space allowances (P < 0.05), particularly at allometric coefficients below 0.015 (P = 0.10), which occurred more frequently in the belly and deck compartments of the trailers, and also at high space allowances in the deck (allometric coefficients > 0.035). The proportion of total compromised animals decreased with more years of truck driving experience (P < 0.001). Mortality was greater in cattle loaded at auction markets compared to feedyards and ranches (P < 0.01). Cull cattle, calves and feeders appear to be more affected by transport based on the likelihood of becoming non-ambulatory and dying within a journey. Most important welfare concerns during long distance transport include the total journey duration, too low or high space allowances, too high or too low ambient temperature, and the experience of the truck drivers.
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