EFFECT OF RECOMBINANT GROWTH-HORMONE AND CHROMIUM PICOLINATE ON CYTOKINE PRODUCTION AND GROWTH-PERFORMANCE IN SWINE

The effect of dietary chromium picolinate (CrP) and recombinant porcin e growth hormone, somatotropin (rPST) administration on growth perform ance and cytokine production in Landrace-Poland China gilts was determ ined using a 2 by 2 treatment array. Treatments were: (I) control (bas al diet), (2) CrP-supplemented diet (basal diet + 300 mu g Cr3+/kg die t as CrP), (3) rPST (100 pg/kg body weight/day), and (4) rPST + CrP. C rP-supplemented diets were fed beginning at 20 kg body weight through 90 kg. Administration of rPST was begun at 60 kg weight and continued through 90 kg. All rPST treated pigs demonstrated improvements in grow th performance versus controls. Pigs given CrP-supplemented diets show ed no differences in growth performance. At 90 kg, pigs were challenge d with endotoxin (lipopolysaccharide, 0.2 mu g/kg i.v.). Blood samples were collected at 0, 1, and 3 h postchallenge. Plasma IL-6 levels inc reased from 23 U/ml at time 0 to 1,927 U/ml at 3 h for control swine. Swine from the CrP treatment group had IL-6 levels of 8,130 U/ml at 3 h post-LPS. There were no differences in plasma IL-6 from pigs in the rPST and rPST + CrP treatment groups compared to the controls. Endotox in challenge had no effect on either blood glucose levels or induction of TNF-alpha in any treatment group. PBMC from CrP-treated animals pr oduced more IL-2 than peripheral blood mononuclear cells from all othe r groups.