|Carroll, Jeffery - Jeff Carroll|
Submitted to: Joint Abstracts of the American Dairy Science and Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/18/2009
Publication Date: 10/18/2009
Citation: Behrends, S., Schmidt, T., Keisler, D., Dailey, J.W., Buntyn, J., Sykes, D., Hulbert, L.E., Cooley, K., Dawson, D.T., Carroll, J.A. 2009. Evaluation of the stress response of heifers during transportation [abstract]. Annual meeting of the American Dairy Science Association, July 12-16, 2009, Montreal, Canada. Journal of Animal Science 87(E-Supplement 2):#387.
Technical Abstract: To evaluate the stress associated with transportation; 22 heifers (326 ± 47 kg) were randomly assigned to a control (Con) or transport (Tran) group. On d 0, 12 h prior to the transportation, heifers were weighed and fitted with an indwelling rectal temperature (RT) probe, jugular catheters, and heart rate (HR) monitors. On d 1, all heifers were haltered and tied for 2 h prior to transportation. At the end of the 2 h period all heifers were weighed, controls were returned to their tie stall, and transported heifers were loaded on the trailer for transport. The first transport period (FTP) began when Tran heifers were loaded on a trailer with 12 individual stanchions and Con heifers were returned to tie stalls. Blood samples were obtained throughout the 4 h transport period (Con and Tran heifers) at 30-min intervals. After transport, Tran heifers were taken to a new location, unloaded, and weighed; blood samples were obtained for 2 h post-transport. Simultaneously, Con heifers were weighed and blood samples obtained. Heifers were allowed a rest period for 14 h. After the rest period on d 2, heifers were subjected to a second transport period (STP; same protocol as in FTP). Serum was analyzed for cortisol (CS), insulin-like growth factor-1 (IGF-1), and growth hormone (GH). The FTP resulted in a 6% loss in BW for the Tran heifers as compared to a 2.5% loss for the Con heifers (P<0.001). Overall, BW loss was 2% greater (P>0.02; FTP and STP combine) for Tran heifers compared to Con heifers. During FTP (P < 0.001) and STP (P < 0.002) Tran heifers had an elevated RT compared to Con heifers. Prior to and post transport (both FTP and STP), CS did not differ between the treatment groups. Differences (P < 0.05) in CS were observed starting 1 h into the FTP and 30 min into the STP. After three h in transit, no difference (P greater than or equal to 0.05) was observed in CS concentrations for both the FTP and STP. Results of this study indicate that transportation can be an acutely stressful event, as seen with increased CS concentrations, increased RT, and increased BW losses. However, after 3 h, it appears that heifers are able to acclimate to initial stress induced by transportation.