Immunomodulation with β-1,3/1,6-glucan (Immustimr) affects growth performance and resistance to Escherichia coli respiratory infection of broiler chickens

s of papers 57 POSTERS Environment and Management 236 Effects of feeding blends of grains naturallycontaminated with Fusarium mycotoxins on immune parameters of broiler chickens. H.V.L.N. Swamy*1, T. K. Smith1, N. A. Karrow1, H. J. Boermans1, and A. E. Sefton2, 1University of Guelph, Guelph, ON, Canada, 2Alltech Biotechnology Center, Nicholasville, KY. There are contradictory literature reports on the susceptibility of broiler chickens to the feeding of deoxynivalenol (DON)-contaminated grains. Earlier studies in our laboratory have shown that performance indices of broiler chickens are reduced by the feeding of grains naturallycontaminated with DON, fusaric acid (FA), zearalenone (ZEN) and 15acetyldeoxynivalenol (15-DON). Information on the effects of feeding such materials on immune parameters of broiler chickens is limited. Three hundred and sixty, day-old male broiler chicks were, therefore, fed diets containing grains naturally-contaminated with Fusarium mycotoxins for 56 d. The diets included; (1) control (0.56 mg/kg DON, 15.2 mg/kg FA) (2) low level of contaminated grains (5.9 mg/kg DON, 19.1 mg/kg FA, 0.4 mg/kg ZEN, 0.3 mg/kg 15-DON) (3) high level of contaminated grains (9.5 mg/kg DON, 21.4 mg/kg FA, 0.7 mg/kg ZEN, 0.5 mg/kg 15-DON) and (4) high level of contaminated grains + 0.2% polymeric glucomannan mycotoxin adsorbent (GM polymer). Peripheral blood monocyte numbers decreased linearly in birds fed contaminated grains. The feeding of contaminated diets linearly reduced B cell count on d 56, while T cell count on d 28 responded quadratically to the feeding of contaminated grains. The feeding of contaminated diets did not significantly alter serum or bile immunoglobulin concentrations, contact hypersensitivity to dinitrochlorobenzene, or antibody response to sheep red blood cells. Supplementation of GM polymer to the contaminated diet non-specifically increased total white blood cell and lymphocyte counts, while preventing mycotoxin-induced decreases in B cell counts. It was concluded that though feeding of grains naturally-contaminated with Fusarium mycotoxins altered the numbers of leukocyte subpopulations in the peripheral blood of broiler chickens, the changes were not enough to cause functional alterations in immune response.