Author
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SWANSON, J - KANSAS STATE UNIVERSITY |
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Morrow, Julie |
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Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/3/2001 Publication Date: 9/30/2001 Citation: Swanson, J.C., Morrow, J.L. 2001. Cattle transport: Historical, research, and future perspectives. Journal of Animal Science. 79:E102-E109. Interpretive Summary: A symposium on animal transportation was held at the American Society of Animal Science in Baltimore, MD in July 2000. A literature review of transportation issues for beef cattle was presented. Historical perspectives identified the development of transport for cattle from ship to rail to present day truck transport. Research that has been conducted on transportation of cattle indicates that both handling the animals while loading and the actual transportation is stressful. Physiological measures of stress, including concentrations of stress hormones (cortisol) and measures of the immune system have been used to identify transportation as a stressor. In general, the immune system is suppressed during transportation, which can lead to increased disease susceptibility. Behavior has also been studied in transported cattle. Animal density within the transport vehicle has the greatest influence on behavior. Older rcattle prefer to stand up to keep their balance while young calves prefer to lie down. Various practices have been used to reduce transport stress (vitamins, high-energy diets, electrolyte therapy) but have been relatively unsuccessful. Other factors that contribute to transport stress are truck design, route of travel and driver training. An important question that remains unanswered is the connection between transportation stress and levels of pathogens that are important from a food safety standpoint. The United States has fallen behind in the investigation of transportation of beef cattle and how such transport impacts welfare and food safety. We risk accepting standards derived from research outside the United States when regulatory oversight eventually becomes a reality for livestock transportation. Technical Abstract: Transportation & handling is generally regarded as stressful to cattle & includes both physical & psychological stimuli that might be aversive. Historical accounts relate high mortality during the early days of transport & concerns for the welfare of cattle that are similar to those today. Behavior, pathology, & physiology are all used to identify stress in nresponse to transportation. Physiological measures indicate that transport of cattle can result in immune suppression, which can lead to increased susceptibility to disease & might result in increased pathogen shedding. Empirical evidence shows that the neutrophil-to-lymphocyte ratio is markedly increased when cattle are handled & transported. Agonistic behavior also seems to be decreased by crowding & motion of the truck. Loading, loss of balance, & falling are distressful to cattle. For example, mean heart rates for cattle transported on smooth roads are lower than for cattle transported on rough country or suburban roads with frequent intersections. Young cattle (less than 4 wk-of-age) do not tolerate transport as easily as older cattle, & young cattle do not show a typical physiological stress response as seen in older cattle. This fact, along with mixing practices typical of loads of calves, may make these animals more susceptible to disease. Various remedial strategies have been attempted to decrease cattle response to transportation stress. These approaches to managing transport stress have met with little success. Newer methods to reverse the negative physiological responses & to assess behavior during transport are needed. Also research is needed to elucidate the relationship of transport stress to the spread of pathogens of concern to food safety. |
