A team of researchers at ̽̽ is seeking solutions to help combat mastitis, a costly health problem among dairy cows that can be challenging for herd health on organic farms. With the use of traditional microbiology plus next-generation, high-throughput sequencing technologies, the team is exploring how different cow bedding systems impact a cow’s udder microbiome, milk production and risks for developing mastitis.
Mastitis is an inflammation of a cow's udder and can be caused by several types of bacterial pathogens, including some found in cow bedding. Infected cows will produce lower quality and less quantity of milk. If not identified and treated early, mastitis could become a chronic condition through a cow’s lifetime. Managing mastitis on organic farms can be more challenging because organic standards in the U.S. restrict the use of antibiotics to treat infections. If a cow has to be treated with antibiotics, it must be removed from organic production, thus the incentive to avoid antibiotic use.
Animal and Veterinary Sciences Associate Professor John Barlow and Plant and Soil Sciences Professor Deb Neher are leading a project comparing bedding management practices on organic farms, to find sustainable and cost-effective strategies that help reduce mastitis infection risk. The team is specifically testing "bedded pack" winter housing systems, a bedding strategy that gives livestock a large, bedded pen for resting and walking rather than individual stalls.
“Because there are no approved products for mastitis treatment in U.S. organic cattle, organic dairy farmers must rely on disease prevention strategies. This includes emphasizing housing systems that limit exposure to mastitis pathogens,” said Barlow. “There is some evidence to suggest that cows in bedded packs have improved milk quality and reduced risk for mastitis, but we don’t fully understand the science behind why this may be. Our project is one step in understanding the potential interactions between cows and the microorganisms in their housing environments.”
A Multi-Dimensional Approach
With a project team of veterinary scientists, biologists, and Extension specialists, Barlow and Neher are studying how beneficial microbes in the bedding environment and a cow’s udder may impact susceptibility to mastitis infection. Undergraduate and graduate students are also part of the team, including microbiology major Graecia Pacheco, who spent last summer in the Barlow Lab as a student researcher in the CALS Life Sciences Leadership Program.
Funded by the USDA’s , the project has outreach and education components as well. Organic dairy farmers across Vermont were surveyed to assess current practices, and the economic and environmental trade-offs of different systems. A management guide of best practices to reduce mastitis risks on organic dairy farms is in development.
“We need to better understand the role of microbes in these environments, but we also need to consider the farmer’s perspective, costs associated with different housing systems and opportunities for farm viability,” said Juan Alvez, research associate with ̽̽ Extension’s Center for Sustainable Agriculture.
Organic dairy standards in the U.S. require that cows graze pasture but can be brought indoors during the non-grazing season or during inclement weather. The team’s found that most farms were using a more traditional indoor housing system like tiestalls (46%) or freestalls (29%). Only 15 percent use a bedded pack system for at least some of their cattle, and most of these farms used bedded packs in combination with some other housing system. Only 6 percent of farms solely used bedded pack systems for their adult cattle.
Bedded pack systems enable cattle to move freely in their housing and can be more cost effective to build compared to a conventional barn, but the survey demonstrates they have not yet been widely adopted in Vermont. The team is continuing to explore farmers' perceptions of their housing systems, including the potential trade-offs of bedding and manure management in different systems.
A Veterinarian Joins the Team to Research Dairy Animal Health
Caitlin Jeffrey is a doctoral student who brings her expertise as a large animal veterinarian to the bedded pack project. She grew up in Vermont and received a doctorate in veterinary medicine from Cornell University. After six years as a large animal vet working primarily with dairy cows, she switched her focus to dairy animal health research. Jeffrey said, “after some time in clinical practice, I wanted to work in a different capacity within dairy and production medicine. Instead of improving the condition of one animal at a time, I shifted my focus to animal health research to affect positive change on a broader scale.”
Jeffrey appreciates the challenges of achieving excellent milk quality and herd health on organic dairy farms. With limited options for treating mastitis on these farms, she hopes to better understand infection dynamics using a bedded pack system. She said, “prevention is key in mastitis control on organic dairies and managing a cow’s bedding is a huge piece of that puzzle.”
For her doctoral thesis, Jeffrey is evaluating how mastitis risk due to different groups of bacterial organisms may differ in bedded pack systems compared to tiestalls. She hopes her work will contribute to a better understanding of the relationship between bedding and intramammary infections in bedded pack systems, helping to inform producers as they consider changing or building new animal housing facilities.
Barlow feels fortunate to have Jeffrey conducting her doctoral studies in his lab. While their current research is directly applicable to Vermont’s organic dairy farms, the findings will have relevance to all sectors of the dairy industry, independent of farm size, management style or the food products they sell.
