Effects of Chromium Supplementation and Lipopolysaccharide Injection on the Immune Responses of Weanling Pigs

Abstract

Sixteen specific pathogen free 4-wk-old crossbred weanling pigs were allotted into a 2x2 factorial experiment to evaluate the effects of chromium (Cr) on the immune responses after lipopolysaccharide (LPS) injection. Two factors included (1) no Cr or 400 ppb Cr supplementation from chromium picolinate (CrPic) and (2) LPS injection (200 μ g/kg BW, intraperitoneally) on day 21 (d 21) and 35 (d 35) as compared with saline application. Plasma samples were obtained from all piglets before (0 h) and at 2 h, 4 h, 8 h, and 24 h after LPS injection. The changes in tumor necrosis factor-α (TNF-α) and leukocyte populations after LPS injection were not significant on d 21. On d 35, the plasma TNF-α level was increased at h 2 postinjection, and supplemental Cr reduced the TNF-α level. The leukocyte populations had changed profoundly and lymphocyte subsets of CD2+ and CD8+ were reduced at 8 h postinjection. The blood granulocytes were increased and the percentage of CD2+ was reduced in the Cr-fed group on d 35. Furthermore, Cr supplementation decreased the blastogensis of concanavalin A-stimulated peripheral blood mononuclear cells (PBMC) on d 21. These results suggest that 400 ppb Cr supplementation from CrPic in diets may modulate the immune responses in weanling pigs during LPS injection. (Asian-Aus. J. Anim. Sci. 2000. Vol. 13, No. 10 : 1414-1421).