|Matteri, Robert - Bob|
|Carroll, Jeffery - Jeff Carroll|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2000
Publication Date: N/A
Technical Abstract: This study evaluated potential differences in immunological responses between an LPS and E. coli challenge in the weaned pig. Forty weaned pigs (14 d, 5 kg) were used in 2 experiments (EXP 1 and 2). In EXP 1, pigs were allotted to 1 of 2 treatments: 1) Cont; i.p. injection of saline or 2) i.p. injection of LPS (150 ug/kg BW). In EXP 2, pigs were also allotted to 1 of f2 treatments: 1) Cont; oral dose of sterile culture media (5 ml) or 2) 5 m oral dose of E. Coli (100 million CFU/ml). Starter rations were fed for 7 d prior to immunological challenges. On d 6 post weaning, all pigs were non-surgically fitted with a jugular cannulae. On d 7 of EXP 1, pigs received their respective i.p. treatments followed by blood sampling every 15 min for 3 h. On d 7 of EXP 2, pigs received their respective treatments followed by blood sampling for 10 h. Serum TNF-alpha and IFN-gamma were assessed by porcine specific ELISAs. In the LPS challenged group, there was a time x treatment effect for serum TNF-alpha (P<.0001) and IFN-gamma (P<.0001), where the first significant difference in serum TNF-alpha was at 0.75 h with 1.38 ng/ml (P=.01). Peak TNF-alpha was 10.85 ng/ml at 1.25 h post-LPS. The first significant difference in serum IFN-gamma was at 1.75 h with 187.1 pg/ml (P=.01). Peak IFN-gamma was 995.4 pg/ml at 3 h. In the E. Coli challenged group, there was no difference in the serum TNF-alpha, however, there was a significant time x treatment difference in serum IFN-gamma (P<.001). There was a trend for E. coli to increase serum IFN-gamma beginning at 5 h compared to controls (P=.14). Peak IFN-gamma was 26.2 pg/ml at 7 h and remained at that level for the duration of the study. These results demonstrate that LPS and E. coli challenges induce very different immunological profiles in the weaned pig.