Grant will help sustain Cornell Johne's research

Grant will help sustain Cornell Johne's research

- New grant builds on results of current project.

- Risk assessment models under development.

- Tools to help build optimal MAP-free milk programs.

RESEARCHERS with Cornell University's College of Veterinary Medicine have received a new $500,000 grant over five years from the U.S. Department of Agriculture's National Institute of Food & Agriculture that will allow them to continue their research to identify Mycobacterium avium subspecies paratuberculosis (MAP) in milk, determine risk factors for milk contamination and document recommended intervention strategies to make milk safer.

MAP is a bacterium that is linked to Johne's disease in cattle and possibly Crohn's disease in people. According to Cornell, it incites an infection in ruminant animals that takes about four years before showing clinical signs. Dairy cows will typically have had two calves during that period, and those calves can contract the infection from their mothers and produce thousands of gallons of milk before clinical signs appear.

Recent studies have shown that MAP in milk can survive pasteurization, which has raised human health concerns, the announcement said.

Once MAP has infiltrated a herd, the cows are widely susceptible to Johne's disease, which is contagious, chronic and often fatal. The disease is blamed for up to $250 million in annual losses in the U.S. dairy industry.

The new grant will allow Cornell to build on the results of the current $2.5 million project, which has been under way since 2009.

The researchers are in the midst of a nine-year longitudinal study to gather DNA from four generations of cows and bacteria, said Ynte Schukken, principal investigator and professor of epidemiology and herd health at the college.

"Our study covers the entire spectrum, with data and samples collected from the field cultured in the lab and bacteria and host DNA sequenced using the most modern genomic methods," Schukken said. "Because of this unparalleled nine-year data set, we have the potential to unravel the mysteries of Johne's disease, a very slow-going and devastating infection on dairy farms."

The researchers, including Cornell professor of population medicine and diagnostic science Yrjo Grohn and scientists from The Pennsylvania State University, the University of Pennsylvania and the University of Maryland, will:

* Validate the effectiveness of a current test used to identify MAP;

* Analyze data from two herds with a known MAP infection prevalence and cross-sectional data from 300 dairy herds with the complete range of MAP infection prevalence, focusing on the relationship between management practices and MAP contamination of milk;

* Develop risk assessment models that explain and predict MAP contamination of raw milk, and

* Use models they developed to design optimal, sustainable MAP-free milk programs.

Schukken's investigation will extend prior results that have already explained transmission patterns of MAP at the molecular level, developed mathematical models for predicting transmission, devised control programs and monitored the success rates of those programs, the announcement said.

"Our immediate goal is to provide dairy farmers with the tools they need to produce milk that is free of MAP," Schukken said. "Evidence from previous work we've done proves that a high percentage of dairy farms in the U.S. have MAP-infected cattle, so reducing viable MAP in raw and pasteurized milk is of importance -- first for the health and well-being of the cows (and) also, because of the possible connections to Crohn's disease, for the health and well-being of people."

Volume:85 Issue:02

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