Effect of transport on feeder calves
Cole, N.A.; Camp, T.H.; Rowe, L.D.; Stevens, D.G.; Hutcheson, D.P.
American Journal of Veterinary Research 49(2): 178-183
1988
ISSN/ISBN: 0002-9645 PMID: 3348528 Document Number: 308635
One hundred fifty feeder steers (mean body weight, 195 kg) were assigned to 1 of 3 transport groups and were deprived of feed and water (fasted) for 24 hours. Additionally, calves were transported on a commercial livestock trailer for 0 (control-fasted only), 12 (short haul), or 24 (long haul) hours. Blood samples were obtained from the jugular vein before calves were loaded on the transport vehicle and immediately after calves of the long-haul group returned to the research feedlot. Complete blood counts were performed and 32 mineral, enzyme, and biochemical constituents were measured. Calf morbidity mortality, and average daily weight gain were evaluated during the next 56 days. Duration of transport did not affect average daily gain; however, calves of the short-haul group had significantly (P < 0.05) higher morbidity and mortality than did those of the control and long-haul groups. In all groups, results of differential leukocyte counts were indicative of stress response. Significant (P < 0.05) linear contrasts were observed between duration of transport and erythrocyte, leukocyte, segmented neutrophil, lymphocyte, and eosinophil counts and results of serum enzyme (alanine transaminase, hydroxybutyrate dehydrogenase, total lactate dehydrogenase [LD], and LD-1, LD-3, and LD-4 isoenzymes), iron, urea nitrogen, .beta.-globulin, glucose, and urea nitrogen-to-creatinine ratio determinations. Significant (P < 0.05) quadratic contrasts were observed between duration of transport and serum unsaturated iron binding capacity, total iron binding capacity, and LD-5 percentage. Calf source had a significant (P < 0.05) effect on almost all variables tested. Results indicated that transport is a stressful event to feeder calves; however, other factors, possibly related to the timing of stress events or adaptation to several different stressors during a short period, may have a greater effect on feeder calves' subsequent health.