New study focuses on food safety practices on small and medium-size farms

Apr 8, 2015

To improve food safety, UC Agriculture and Natural Resources studies every link in the food chain, from producers' farms to consumers' kitchens.

A new UC study is looking at small to medium-size farms, both organic and conventional production, to identify on-farm food safety practices that are specific to farms that raise livestock and grow fresh produce. These are farms that sell their products directly to consumers at farm stands and farmers markets or through community supported agriculture (CSA).

“Much of the produce food-safety research in recent years has focused on large commercial farms,” said project co-leader Michele Jay-Russell, microbiologist and program manager at the Western Center for Food Safety at UC Davis. “In this study, we hope to identify best practices that may be unique for smaller operations and to share this information with the farmers.”

The 12-month study is being conducted on commercial farms in Northern California, from the Shasta Cascade region down to the Central Valley, including the coast. Fecal-borne pathogens can be spread to fresh fruits, nuts, and vegetables through animal intrusions, or indirectly through contaminated water or soil. The researchers are looking for the best practices that prevent pathogens from contaminating fresh market tomatoes and leafy greens such as lettuce and spinach.

“Raising livestock and growing fresh produce together for the local community presents certain opportunities and challenges from a food safety perspective,” said Alda Pires, UC ANR Cooperative Extension urban agriculture and food safety specialist in the School of Veterinary Medicine at UC Davis, who is leading the project with Jay-Russell, who is liaison to the Western Institute for Food Safety and Security.

“Our research aims to identify practical, scale-appropriate approaches that reduce risk from pathogens, while maintaining sustainable and economically viable family farms in Northern California,” said Jay-Russell, who has a small dairy goat herd in the Yuba Foothills.

Researchers will visit participating farms to collect samples of their produce, water, compost and livestock feces to test for bacteria. Farmers will be asked to complete a short survey about farm management practices. The testing is free and the farm identities are confidential.

“We anticipate publishing our results, without revealing farm names, next year and sharing the findings with the agricultural community through workshops and trainings,” said Pires, who grew up on a small family farm in Portugal.

A USDA National Institute for Food and Agriculture (NIFA) multi-state grant is funding this study and a similar study in the northeast – New Jersey, Maryland and Delaware – looking at microbial food safety issues potentially unique to small and medium-scale farms. The results of that study have been published in the International Journal of Food Microbiology and Applied Environmental Microbiology.

For more information about this food safety study, contact Alda Pires, UC ANR Cooperative Extension urban agriculture and food safety specialist, at (530) 754-9855 or

By Pamela Kan-Rice
Author - Assistant Director, News and Information Outreach