YEAST TREATMENT TO REDUCE SALMONELLA AND CAMPYLOBACTER POPULATIONS ASSOCIATED WITH BROILER-CHICKENS SUBJECTED TO TRANSPORT STRESS

The prevalence of Campylobacter and Salmonella on retail poultry carca sses remains a significant public health concern. The stresses associa ted with transporting poultry prior to slaughter have been shown to in crease pathogen populations both in the intestinal tract and on the ca rcass exterior. The yeast, Saccharomyces boulardii, was evaluated for its ability to reduce populations of Salmonella and Campylobacter in b roiler chickens subjected to transport stress. Chicks, inoculated with individual strains of Salmonella and Campylobacter were held for 6 wk and then divided into two groups with half of the chickens receiving 10% dried yeast in the feed for 60 h. The birds were then caged and tr ansported to simulate commercial conditions. After euthanatizing the b irds, the ceca were aseptically removed and analyzed for Salmonella an d Campylobacter. With no yeast treatment, transport stress caused the Salmonella colonization frequency to increase more than fivefold, from 3.3 to 16.7%. Yeast treatment significantly reduced the frequency of Salmonella colonization to lower than prestress levels, as no Salmonel la were recovered from the ceca of these birds (P < 0.05). Similar res ults were obtained from birds challenged with a mixture of Salmonella and Campylobacter strains. Before transport, 53.3% of these chickens w ere positive for Salmonella. Transport stress increased the colonizati on rate to 67.5% in control birds, whereas the colonization of yeast-t reated chickens decreased to 40% (P < 0.05). Frequency of Campylobacte r isolation from the ceca was not affected by treatment, but Campyloba cter populations present in the ceca were significantly reduced in the mixed strain trial (P < 0.05).