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 thirty-two hens at 38 weeks of age were challenged both orally (OR) and intracloacally (IC) with nalidixic acid resistant SE (SE NAR ). Hens were individually housed in conventional wire laying cages and randomly allocated to four treatments (T) with eight hens per replicate: 1) No SE NAR challenge (T1; basal diet), 2) SE NAR challenge (T2; basal diet), 3) SE NAR challenge: basal diet with a blend of Saccharomyces- Torula yeasts and yeast cell walls (T3; intact yeast), and 4) SE NAR challenge: basal diet with enzymatically-modified yeast products blend (T4; enzyme-modified yeast). The excreta samples were 100% positive for SE NAR at 3 days post-infection (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 SE NAR 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 SE NAR counts (cfu/g) in the ceca from 4.3 log 10 to 2.7 and 1.95 log 10 , respectively, compared to T2 ( P < 0.05). The cecal count of SE NAR was 1.6 log 10 lower in T3 and 2.3 log 10 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.