Descriptive survey and Salmonella surveillance of pastured poultry layer farms in California



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While pasture-raised poultry comprises a small portion of the commercial poultry industry in North America, these alternative rearing systems have become increasingly popular. As such, it is critical to improve our understanding of husbandry practices and prevalence of zoonotic and epizoonotic diseases in these systems. This research reviews the results of a survey sent to 82 commercial pastured poultry farms in California. While the survey response was low(13.4%), it was enhanced by detailed in-person inter-views and farm visits. In addition, we conducted dragswabs forSalmonellaEnteritidis. On average, farms uti-lized 12.3% of their total farmland for pastured poultry operations, which often coexisted with other live-stock (45%), touch crops (27%), and non-touch crops(45%). While the mean (44.6 sq. ft./hen) and median(22.2 sq. ft./hen) pasture stocking densities were within auditing guidelines, the mean (1.2 sq. ft./hen) and median (0.5 sq. ft./hen) coop stocking densities were below the pending USDA (2016) guidelines recommended in 7CFR Part 205. Drag swab results showed the presence of Salmonella Enteritidis (SE) in the environment of one of the 11 farms (9.1%). In addition,SalmonellaPullo-rum (SP) whole blood agglutination tests were used to understand the prevalence of Salmonella spp.inlayinghens within the studied farms. Results showed the presence of antibodies in flocks at six of the seven non-SEvaccinated farms, with a mean on-farm prevalence of25.6% in laying hens. Logistic regression was used to determine risk factors for Group DSalmonellaexposurein non-vaccinated flocks, using the SP blood agglutination data as the dependent variable and the survey questions as the independent variables. Statistically sig-nificant (P<0.05) risk factors included exposed wirefloors and flock size. These results improve our understanding of Salmonella prevalence and husbandry practices on commercial pastured poultry farms in California.