Consumers today are increasingly concerned about the safety of their food. In addition, consumers are further removed from the farm and have a lack of understanding about modern food production practices.
As consumer concerns and preferences evolve, dairy producers - as part of the food production chain - must respond. By making small management changes, dairy producers can enhance dairy product food safety and help meet evolving consumer expectations. Here are seven things you can do to improve food safety pre-harvest:
1. Reduce sources of microbial contamination.
Practice excellent hygiene as it reduces opportunities for growth and transmission of pathogenic bacteria. Routine assessment of farm hygiene through the use of scoring systems can be used to help make changes and monitor progress.
2. Adopt uniform milking practices.
The effective use of pre-dipping and forestripping can enhance milk safety. For example, the use of an iodine pre-dip reduces standard plate counts and coliform counts by five- and six-fold. Pre-dipping reduces the risk of isolation of Listeria monocytogenes from milk filters by nearly four-fold, and forestripping reduces the risk of contamination of milk with L. monocytogenes by two and a half times.
3. Identify high-risk practices and herds.
Dairy cattle are reservoirs for several human pathogens. The diagnosis of Salmonella spp., or L. monocytogenes in an animal should trigger an alarm that other animals may be infected. Animals with salmonellosis have an increased risk of fecal shedding of Salmonella spp., and asymptomatic animals regularly shed Campylobacter jejuni, too. Employees should be educated about the potential human health risks and how to avoid them.
4. Screen milk for coliforms.
Routinely test bulk tank milk for the presence of coliform bacteria, which indicates fecal contamination. Coliform bacteria can contaminate milk through poor udder preparation or unhygienic handling of the milking machines. Coliform counts should be less than 100 cfu for milk that will be pasteurized before consumption, and less than 10 cfu if raw milk will be consumed.
5. Reduce your somatic cell counts.
Increased prevalence of subclinical mastitis in a dairy herd (as demonstrated by high bulk tank somatic cell counts) indicates management practices associated with reduced food safety. SCC values were higher in herds where verotoxigenic E. coli and L. monocytogenes were cultured from bulk tanks, as compared to herds that tested negative for those pathogens. Facilities of herds with higher SCC values have been demonstrated to be dirtier than facilities of herds with lower SCC values. The risk of having an antibiotic residue in the bulk tank is two to seven times higher for herds with bulk tank SCC values above 400,000 cells/mL., as compared to herds with values less than 250,000 cells/mL. Reductions in SCC regulatory limits would further improve the image of safety and quality of U. S. dairy products.
6. Market only clean and healthy cull cattle.
Market cattle may represent the greatest risk to the safety and quality image of the dairy industry. In one survey of California dairy producers, 23 percent and 71 percent reported that cow carcasses had been condemned during the five previous years due to antibiotic residues or infection and illness. Low body condition score has been successfully used as a predictor of illness in market cattle, and it is likely that buyers of the future may reject thin cows. Work with your veterinarians to establish culling plans that include realistic treatment plans and standards for BCS.
7. Practice responsible antimicrobial use.
Antibiotic usage on farms is increasingly blamed for the emergence of antibiotic resistance in human pathogens. All dairies should have written treatment plans that are developed and routinely reviewed and updated by their veterinarian. The treatment plan should ensure the health and well-being of the animals, while limiting antibiotic use to justifiable uses. When isolation of bacterial pathogens is possible, susceptibility tests that generate quantitative outcomes (i.e. minimum inhibitory concentrations) should be performed to guide selection of appropriate antibiotics.
Pamela Ruegg is an extension milk quality veterinarian and associate professor at the University of Wisconsin.