WSU researchers look to quantify dairy cow health and wellbeing

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Source: Washington State University, By Josh Babcock, College of Veterinary Medicine

Washington State University researchers are using a human medical technique to measure the impact of common diseases affecting dairy cow production and animal wellbeing.

A research team led by Craig McConnel, a veterinary medicine extension associate professor, will apply the concept of a disability-adjusted life year (DALY) summary measure of health to veterinary medicine. The DALY was developed in the 1990s for use in human medical epidemiology to measure overall disease burden, expressed as the number of years lost due to ill-health, disability, or early death. It is a metric used by the World Health Organization to assess the global burden of disease.

The use of the DALY has allowed epidemiologists to gauge how various diseases and injuries affect human quality of life quality, and the concept will now provide dairy producers and their veterinarians a novel approach to understanding the effectiveness and consequences of their health management decisions.

“It is a conceptually challenging way of thinking about disease, but it allows us to understand the cumulative impact of disease on animal wellbeing and productivity over the course of a life,” McConnel said. “We currently don’t have effective measures of the lifetime burden of disease for livestock.”

The project is funded by a $1 million Inter-Disciplinary Engagement in Animal Systems, 5-year grant from the United States Department of Agriculture.

McConnel, his colleagues at WSU’s College of Veterinary Medicine, and researchers from WSU’s College of Agriculture, Human, and Natural Resource Sciences plan to use the funding to measure the lifetime burden of different diseases on dairy cows by documenting standard measures of productivity such as milk production and reproductive efficiency alongside physiological impacts described through molecular diagnostics. McConnel said that wellbeing, disease, productivity, and longevity are directly related.

“They are all intertwined,” McConnel said. “We are just trying to be more nuanced about understanding the duration, severity, and lifetime consequences of disease – all the pieces that lead to productivity and success within the herd.”

Once collected, McConnel and his team will use the data to determine the combined burden of some of the most common diseases affecting calves and cows, including diarrhea, respiratory disease, mastitis, lameness, and other illnesses.

“If you are singularly focused on individual episodes of disease, you can lose sight of the larger context and interrelatedness of dairy cow disease,” McConnel said. “We believe that an innovation such as a summary measure of health can help integrate the impacts of disease on productivity, longevity, well-being, and economic opportunity costs.”

The team will evaluate blood-based gene expression, proteins and metabolites, and fecal microbial communities to help assess the wellness of an animal beyond typical clinical signs of disease.

“Some of the molecular work we are doing is cutting edge,” McConnel said. “We think it will help describe to us on that day what a cow is experiencing health-wise, and how that impacts productivity and success within the herd later in life. The goal is to achieve the best life possible in terms of health and wellbeing for the animal.”

The research will be conducted on two private dairies in Washington state.

In addition to understanding how different diseases affect wellbeing and productivity, the grant

includes extension and education opportunities that are connected to the research process.

“Throughout the project we will provide veterinary students opportunities to hone their clinical skills while providing producers and their veterinarians additional insight into health management,” McConnel said. “In the end, we anticipate engaging veterinarians in continuing education, highlighting diagnostics of the future and the effect of health problems on lifetime wellbeing.”