Abstract:

【Objective】 The objective of this study was to explore the changes of immune function and regulation of cytokines in pigs during truck-transportation. 【Method】 The peripheral blood lymphocytes (PBLs) proliferation of normal pigs were stimulated by the serum of stressed pigs alone in different dilution times or with plant haemagglutinin A (PHA) and lipopolysaccharides (LPS) separately. The influence of the stressed serum on peripheral blood T and B lymphocytes proliferation of normal pigs was determined by MTT assay. The concentrations of IL-1β, IL-2, IL-4, IL-6, IL-10 and TNF-a in sera were measured with homologous specific Enzyme-Linked Immunosorbent Assay (ELISA). The correlations between lymphocyte proliferative activity and cytokines expression were analyzed with SPSS 11.0. 【Result】 After 1 h, 2 h and 4 h of transportation, the serum of transported pigs could obviously affect the activity of T, B-lymphocyte proliferation in PBLs from normal pigs at 1:32 dilution. The data was increased following transportation stress and reached to the peak level at 1 h (P＜0.05), then slowly decreased and reached the lowest level at 4 h. The levels of IL-2, IL-6 and IL-10 in sera were increased with transportation stress and reached the peak after 1 h of transportation, then slowly decreased and reached the lowest level 4 h after transportation. The levels of IL-6 and IL-10 in the sera at 4 h were significantly decreased (P＜0.01) compared with the control. The level of IL-2 in sera at 4 h was significantly decreased (P＜0.05) compared with that at 1 h of transportation stress. But there were no significant changes with respect to the IL-1β, IL-4 and TNF-a.【Conclusion】 The immune function could be altered by transportation stress and was also related to the timing of post-stress in pigs. The statistical analysis suggested that IL-6 level in serum may be as a typical biomarker to respond the change of immune function in pigs during truck-transportation.

Key words: pigs')">pigs, transportation stress, immune function, lymphocyte proliferation, cytokines