Effect of Saccharomyces cerevisiae fermentation product on immune functions of broilers challenged with Eimeria tenella.

Three hundred sixty 1-d-old male Arbor Acres broilers were randomly allotted to 6 groups with a 2x3 factorial arrangement of treatments. Three supplemental levels (0, 0.25, and 0.50%) of Saccharomyces cerevisiae fermentation product (XP) were fed to control and Eimeria tenella-infected broilers. Growth performance and immune response criteria were measured after coccidian infection. Broiler ADG was lowered (P<0.01) by coccidian infection and improved by XP supplementation (P=0.04). Supplementation of XP increased CD3+, CD4+, and CD8+ T-lymphocyte counts (P<0.05) and the ratio CD4+:CD8+ in blood (P=0.06) and spleen (P=0.04) as well as ileum intraepithelial lymphocyte count, cecal tonsil secretory IgA counts, serum lysozyme content (P<0.01), and albumin:globulin ratio (P=0.02). These results suggest that dietary XP supplementation could improve immune function and growth performance in coccidia-infected broilers.