New test cuts dairy antibiotic use in half

Dairy farmers can radically cut back on the use of antibiotics in their herds with the use of a new test developed at the Atlantic Veterinary College.

The test helps farmers determine whether mastitis, an inflammation of the udders, requires treatment by antibiotics or whether the cow is best left to fight the infection on its own.

Derwin Clow says that at least once every couple of months one of his cows will develop mastitis. Until recently Clow always dealt with it the same way, by pumping antibiotics into the cow, even though it meant stopping milk production until the drugs were clear from her system.

"You always played it safe, because when you have a sick cow, obviously you want her to get better as quickly as possible, so you treat her with antibiotics," Clow told CBC News on Monday.

Researchers have known for some time that antibiotics are only required for about half of mastitis cases, but there was no simple, inexpensive test available to determine when they were needed.

"I've actually been working on this most of my career, probably for about the last 15 years, trying to find a simple to use technology farmers that can use on the farm in order to make these treatment decisions," said AVC researcher Greg Keefe.

Working with about 50 dairy farmers across the country, Keefe believes he has now developed a test that will work.

The kit consists of a set of cards and an incubator. The farmer takes a sample of milk, dilutes it, and puts the card in an incubator for a day.

"They look at it in 24 hours, and essentially what they have to do is just count the dots on the playing card," said Keefe.

"If it's above a certain threshold, then she has a certain type of infection and they have to treat her, and if it's below then she's getting better on her own so they don't have to treat her."

Clow said by using the test in hand he's buying fewer antibiotics for his cows and as a result producing more milk.

"I would say it's cut it in half, which means a lot of money," he said.

Keefe said Clow's results are fairly typical of others trying the test. He's about to begin a major marketing campaign in the Maritimes.

The kit costs $120 plus another $8 per use.