Submitted to: Proceedings of Allen D Leman Swine Conference
Publication Type: Abstract Only
Publication Acceptance Date: August 30, 2004
Publication Date: September 20, 2004
Citation: Callaway, T.R., Morrow, J.L., Genovese, K.J., Dailey, J.W., Wallace, F.M., Poole, T.L., Lewis, A.R., Dowd, S.E., Edrington, T.S., Anderson, R.C. 2004. Environmental prevalence of salmonella on indoor and outdoor intensive swine farms. Proceedings of Allen D Leman Swine Conference. 31(Suppl.):23. Technical Abstract: Swine can harbor food-borne pathogenic bacteria such as Salmonella in their gastrointestinal tracts, with as many as 25% of U. S. swine carrying the pathogen. Housing sows in farrowing stalls or in farrowing crates has become controversial due to animal welfare-based criticisms. An alternative production system for sows and their litters is to keep them outdoors with access to farrowing huts. One hundred and eight PIC-C22 sows were used to determine the effect of two different production systems on food-borne pathogenic bacteria of sows housed indoors in farrowing stalls (n = 104) compared to sows housed outdoors (n = 104) in English style farrowing huts. Sows were multiparous and were obtained from a single-source farm. Sows were fed once daily (8 am) a completely balanced sorghum based diet. This research was conducted over a 10 mo period from April 2001 to Jan 2002. A total of 8 one acre farrowing radials each contained one wallow. Wall samples (n = 180) were collected monthly from both the stall and the hut using a 10 cm by 10 cm gauze swab and stored in a test tube until further processing. In addition mud and water samples were collected from each wallow. All samples were analyzed for Salmonella using standard laboratory methods used in our lab. No differences (P <0.05) were detected in Salmonella populations between indoor farrowing stalls and outdoor farrowing huts. There was a very low incidence of pathogenic bacteria during this study. All 8 wallows contained Salmonella spp. throughout the study (n = 49 Salmonella isolates), and these Salmonella isolates persisted within some wallows for >5 months and were spread between multiple wallows. Salmonella give was isolated from outdoor sow feces during the study that was genetically indistinguishable by Pulsed-Field Gel Electrophoresis (PFGE) from Salmonella give isolated from wallows (n = 33) throughout the study, indicating that pathogenic bacteria were cycling between swine and their environment. In conclusion, we could not detect a difference between the incidence of food-borne pathogenic bacteria from swine raised indoors or outdoors, but the role of wallows in spreading Salmonella within a swine herd could be quite significant.