Je. Line et al., YEAST TREATMENT TO REDUCE SALMONELLA AND CAMPYLOBACTER POPULATIONS ASSOCIATED WITH BROILER-CHICKENS SUBJECTED TO TRANSPORT STRESS, Poultry science, 76(9), 1997, pp. 1227-1231
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).