Minnesota dairy producers are showing that a concerted effort to control Johne's disease pays off, says Scott Wells, a University of Minnesota dairy veterinarian who specializes in Johne's control.
More than 1,600 Minnesota dairy herds—more than a third of the cows in the state—are involved in either a test-negative or management program.
Several demonstration herds have cut their Johne's prevalence in half after five years. Many had 9% to 10% of animals positive for Johne's at the start of the program and have reduced that prevalence to 3% to 4%.
"Though these herds haven't eliminated Johne's, they are seeing fewer clinical cases,” Wells says.
Since all the herds in the programs do a Johne's risk assessment, there is some variation in management practice. "Most of it has to do with hygiene, particularly around young calves,” Wells says.
Calves should be delivered in clean, dry areas and in individual pens, if possible. In high-incident herds, calves should only receive colostrum from their dams, and then either milk replacer or pasteurized whole milk.
"Some herds try to remove the high-positive animals, and certainly the clinical cases,” Wells says.
"There's nothing special about these recommendations. They are just the basic Johne's control tools most herds should be implementing.”