Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/11/2006
Publication Date: 7/9/2006
Citation: Williams, J.L., Eicher, S.D., Patterson, J.A., Marchant Forde, J.N. 2006. Effects of lairage during transport on innate immune function of swine. Journal of Animal Science. 84(1):417.
Technical Abstract: Long distance transports may significantly affect the health of pigs; thus, adding a rest stop (lairage) during long journeys may improve their well-being. The objective of this study was to determine whether a mid-journey lairage was beneficial to swine immune variables during a 16-h transport. Four replications were conducted, one in each of four seasons. Eighteen-kg pigs were housed in 16 pens (13-16 pigs/pen) with 8 pens/treatment. Lairage (La) pigs were transported for 8 h, given a rest with food and water for 8 h, then transported 8 h. Continuous (Co) pigs were continuously transported for 16 h. Jugular blood samples were collected from 16 pigs (8/treatment) on d 1, 3, 7 and 14 post-transport. Hematocrit and white blood cell (WBC) counts were obtained and neutrophil cell functions (phagocytosis and oxidative burst) and phenotypic cell markers (CD14 and CD18) were analyzed using flow cytometry. There were no treatment by block interactions. In Co pigs, total WBC count was higher on d 1 than La pigs (P<0.001). As expected, granulocyte count in Co pigs was higher than in La pigs on d 1 (P<0.001); further, granulocyte count was lowest on d 3 in Co pigs (P<0.05). In both treatments, lymphocyte count was lower on d 14 than on d 1 (P<0.05). There were more cells expressing CD14 in Co pigs than La pigs on d 1 (P<0.05). In addition, Co pigs on d 1 and 14 had the highest percentage of CD14 and CD18 positive cells (P<0.05) and La pigs had the highest percentages of both on d 14 (P<0.05). Percent phagocytosis was highest on d 7 in the Co pigs (P<0.05); however, in both treatments oxidative burst was highest on d 7 (P<0.05). In both treatments, CD18 percentage was lowest on d 0 (P<0.05). This study indicates that extended transport without lairage alters immune functions which may cause greater susceptibility to pathogens. Partial funding of this study was provided by the National Pork Checkoff.