Effect of enzyme-modified yeast products on Salmonella Enteritidis colonization in different organs of laying hens

Abstract

A study was conducted to assess the effectiveness of yeast-derived products in the recovery of Salmonella Enteritidis (SE) in White Leghorns. A total of 32 hens at 38 wk of age were challenged both orally (OR) and intracloacally (IC) with nalidixic acid resistant SE (SENAR). Hens were individually housed in conventional wire laying cages and randomly allocated to 4 treatments (T) with 8 hens per replicate: 1) No SENAR challenge (T1; basal diet), 2) SENAR challenge (T2; basal diet), 3) SENAR challenge: basal diet with a blend of Saccharomyces-Torula yeasts and yeast cell walls (T3; intact yeast), and 4) SENAR challenge: basal diet with enzymatically-modified yeast products blend (T4; enzyme-modified yeast). The excreta samples were 100% positive for SENAR at 3 d postinfection (dpi) in T2, T3, and T4. By 6 dpi, excreta samples were 87, 62 and 37% positive for T2, T3, and T4, respectively. Hens were euthanized at 7 dpi to harvest liver with gall bladder (L/GB), spleen, ovaries, and ceca. The recovery of SENAR in L/GB was 75, 25, and 37% in T2, T3, and T4 (P < 0.05), whereas that of the spleen was 62, 25 and 37% in T2, T3 and T4 (P < 0.05), respectively. Treatments 3 and 4 reduced SENAR counts (cfu/g) in the ceca from 4.3 log10 to 2.7 and 1.95 log10, respectively, compared to T2 (P < 0.05). The cecal count of SENAR was 1.6 log10 lower in T3 and 2.3 log10 lower in T4 compared to T2. Both yeast derived products reduced Salmonella in internal organs and the ceca of laying hens. Enzymatically-modified yeast (T4) was better than its intact counterpart (T3) in reducing Salmonella counts in the ceca.