RISK OF SHEDDING SALMONELLA ORGANISMS BY MARKET-AGE HOGS IN A BARN WITH OPEN-FLUSH GUTTERS

Objective-To compare prevalence of fecal shedding of Salmonella organi sms and serum antibodies to Salmonella sp in market-age pigs housed in barns with partially slotted floors or solid floors with open-flush g utters. Design-Cross-sectional study of prevalence. Sample Population- Finishing-age pigs deemed by the producer to be within 1 month of slau ghter. Procedure-Fecal and serum samples were obtained from a group of 121 pigs housed in barn with solid floors (31 fecal samples, 30 serum samples) and from a group of about 400 pigs housed on partially slott ed floors (57 fecal samples, 64 serum samples). Fecal samples were sub mitted for bacteriologic culture to detect Salmonella organisms, and s erum samples were tested for antibodies by use of ELISA. Results-Salmo nella agona was isolated from 26 of 31(84%) fecal samples obtained fro m pigs housed in the open-flush gutter barn, compared with 5 of 57 (9% ) fecal samples from pigs in the barn with slotted floors. Median valu e for optical density was higher for serum samples from pigs housed in the open-flush gutter barn. Clinical Implications-Housing of finishin g-age swine in barns with open-flush gutters may contribute to increas ed shedding of Salmonella sp. Analysis of our observations indicated t hat repeated exposure to infected feces is important in prolonging fec al shedding by swine.