Objective-To test feed and feed ingredients on swine farms for Salmone
lla organisms and to analyze data from these farms to determine risk f
actors associated with Salmonella organisms in the feed and feed ingre
dients. Design-Epidemiologic survey and retrospective case-control stu
dy. Sample Population-30 swine farms. Procedure-Samples of feed and fe
ed ingredients and information regarding herd characteristics were col
lected from 30 swine farms, Samples were tested for Salmonella organis
ms, and data complied from herd information forms were examined for as
sociated risk factors between herd characteristics and isolation of Sa
lmonella organisms. Results-Salmonella organisms were isolated from 36
of 1,264 (2.8%) feed and feed ingredient samples and from 14 of 30 (4
6.7%) farms. Thirteen Salmonella sp serotypes and 2 untypeable isolate
s were cultured. Recovery of Salmonella organisms from at least 1 feed
or feed ingredient on a farm was significantly associated with 6 herd
characteristics (lack of bird-proofing, using farm-prepared feed for
finishing-age pigs rather than purchased feed, and housing pigs in fac
ilities other than total confinement in the growing, finishing, gestat
ing, and breeding stages of production, respectively). Isolation or Sa
lmonella so was not associated with a history of salmonellosis on a fa
rm. Clinical Implications-Salmonella organisms were readily isolated f
rom samples of feed and feed ingredients, illustrating that salmonella
e are ubiquitous in a farm environment. implementing sanitary and pest
-control measures continues to be a prudent recommendation, Salmonella
serotypes found in feed and feed ingredients have the potential to ca
use disease in pigs that consume The feed or, ultimately, in people th
at consume pork.