To minimize food safety risks associated with wild and domestic animals, every farm should:
- Identify and assess risks posed by wild and domestic animals.
- Consider methods to prevent and minimize animal entry through the use of fences, noise cannons, or other deterrents.
- Reduce or eliminate animal attractants such as standing water, cull piles, and nesting areas.
- Monitor and document animal activity in the field.
- Conduct field assessments prior to harvest.
- Train all workers to follow company policies regarding monitoring animal activity and proper harvest procedures.
Wild and domestic animals are a food safety concern because they can carry human pathogens in their feces and can spread contamination around fields as they move.
Animals are a natural part of the farm environment, so complete exclusion is not possible. It is still important to limit their access to fields to reduce the risks of contamination from pathogens such as Salmonella, E.coli O157:H7, and Campylobacter jejuni since these pathogens have all been found in animals.
In addition to direct contamination of the crop in the field, it is important to recognize that animal feces could also contaminate water sources used during production, leading to cross-contamination of crops. Large numbers of animals (i.e., flocks of geese, herds of deer, or a large scale cattle operation) represent the biggest risks because they produce large amounts of fecal matter that could enter fields through water runoff, airborne particles, cross-contamination from insects, or by contaminating water sources used during production.
Although dogs and cats may be considered family members and may be used as deterrents to wildlife, they also have the potential to harbor pathogenic microorganisms. Family pets should be kept out of the packinghouse, production fields, and vehicles carrying fresh produce, especially close to harvest. While it is unreasonable to expect complete animal exclusion in the field and packinghouse, steps to identify and minimize their presence should be taken.
Conduct a risk assessment to identify risks posed by wild and domestic animals
Before each season, every farm should identify and assess the risk of wildlife and domestic animal presence in or near fruit and vegetable fields. Proximity to wooded areas or water sources that attract wildlife should be a consideration. Any domestic animals, such as grazing cattle, chickens, or other farm animals, may pose a risk of contamination if runoff occurs from their feces or bedding areas into production fields.
Prevent animal entry through the use of fences, noise cannons, and other deterrents
Animal controls and deterrents may be used when problems are identified or needed based on observations done on the farm. Decoys, such as plastic coyotes, owls, and swans, are effective if they are actively moved around the farm to deter wildlife. Noise makers can also be effective, but animals may become desensitized to the noise over time. Fencing can be an effective deterrent, but it may not be practical for larger farms; however, small portions of fencing may direct animals around high value or sensitive crops to other areas. Nuisance permits may be another option, but check with your local Department of Environmental Conservation (DEC) or the National Resources Conservation Service (NRCS) before choosing this method.
Monitor and document animal activity in the field
Throughout the production season, take an active role in monitoring fields and packing areas for the presence of animals. Be sure to eliminate or properly manage any possible animal attractants such as cull piles, access to water, garbage cans, and dumpsters. Incorporate monitoring into your day-to-day activities on the farm. Document your observations and look to see if there are patterns of animal presence throughout the season. Understanding patterns and seasonal changes in wildlife can help you prevent problems and deter animals from entering production areas.
Conduct field assessments prior to harvest
Before each harvest, an assessment of the field should be done to ensure that there are no obvious signs of animal intrusion or fecal contamination. If feces are found in the field or have come in direct contact with produce, this area should not be harvested. If a large amount of animal activity (i.e. tracks, damaged product) is found, the farm manager should be notified and an assessment of risk should be done to determine what action should be taken next and determine whether the produce is safe to harvest.5
- Option 1: Flag feces or affected crop and do not harvest. Create a buffer zone so that workers will know what areas not to harvest. At minimum, the no-harvest buffer zone should have a 5 foot radius.3
- Option 2: If feces or contaminated crop can easily be removed and the contamination is somewhat isolated, be sure to properly clean and sanitize all equipment used to remove contaminated produce or feces, as well as follow proper personal hygiene (i.e., hand washing) to reduce cross-contamination risks.
- Option 3: If fecal contamination or animal intrusion is extensive, do not harvest the field and/or disk the crop into the soil.
Train all workers to follow company policies regarding monitoring animal activity and proper harvest procedures
Field workers should be trained to recognize the risks associated with animal presence in or around the field as well as the presence of fecal contamination on fresh produce. If fecal material is found in the field, or has directly contaminated produce, workers need to understand how to create buffers and follow the farm policy for leaving or removing the contamination. Workers must also be instructed to wash their hands after handling contaminated produce or fecal material.
- Beuchat, L.R. (2006). Vectors and conditions for preharvest contamination of fruits and vegetables with pathogens capable of causing enteric diseases. British Food Journal, 108(1), 38–53.
- Hanning, I.B., Nutt, J.D., Ricke, S.C. (2009). Salmonellosis Outbreaks in the United States Due to Fresh Produce: Sources and Potential Intervention measures. Foodborne Pathogens and Disease, 6(6), 635–648.
- California Leafy Green Products Handler Marketing Agreement (LGMA). (2011). Commodity Specific Food Safety Guidelines for the Production and Harvest of Lettuce and Leafy Greens.
- Berry, E.D., Wells, J., Durso, L.M., Bono, J.L., Friesen, K.M., Woodbury, B.L., Kalchayanand, N., Norman, K.N., Suslow, T.V., Lopez-Velasco, G., Millner, P.D. 2014. Effect of proximity to a cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens and evaluation of the potential for bioaerosol and pest fly transmission. [Abstract]. Western Food Safety Summit, May 8-9, 2014, Salinas, CA.
- California Leafy Green Products Handler Marketing Agreement (LGMA). (2013) Assessing Animal Activity in the Field.