Working together to get on top of Johne’s

Farmers are not doing enough to check on the health status of purchased cattle – but their vets and auctioneers could hold the key to obtaining such information.

At least half of all beef and dairy herds are infected with Johne’s, leading to infertility, mastitis, lameness and death. But farmers are still not checking the health status of animals before buying them, increasing the likelihood of importing disease into their herd.

Three-quarters of dairy herds buy-in cattle, says Dick Sibley, a vet at West Ridge Veterinary Practice, Devon. “If they don’t check their health status, they stand a pretty high chance of bringing infected animals on to the farm.”

However, because Johne’s lies dormant for the first three to seven years of life, farmers may not know an animal is infected – by which time the disease could have spread throughout the herd.

The bacteria – Mycobacterium Paratuberculosis – are shed by infected cows, and are usually contracted by calves in the calving pen. One infected cow could therefore bring down a whole batch of calves.

An untreatable disease, Johne’s suppresses the immune system, leading to a multitude of other problems and resulting in much higher culling rates, equivalent to a cost of 2-3p/litre. In clinical cases it leads to infertility, scouring, loss of condition, lameness and eventually death.

“Farmers often feel embarrassed to ask about a herd’s disease status, particularly if they are buying from neighbours or people that they know,” says Mr Sibley. “A lot of vendors also don’t know the health status of their cattle, because they’ve never had them tested.”

However, knowing the diseases present on a farm is the first step to eradicating them, so farmers should be testing a sample of 30 high-risk cows – those which are aged four- to eight-years-old and are showing signs of infertility, poor condition or chronic lameness. If they are lucky enough to be disease-free, purchasers will pay £100 more on average for their animals.

“As a purchaser, the first priority is to ask whether the vendor has tested their animals – and if you’re embarrassed to do that, get your vet to ask for you,” says Mr Sibley. “If the vendor hasn’t tested them, you can ask other questions to ascertain the likelihood of infection: have they bought cattle over the past 10 years, and do they buy from a number of different sources? You can also look in the sale catalogue to see how many ear tag prefixes there are – if they are truly a closed herd there will only be one herd prefix.”

However, auctioneers could play an important role by flagging up the health status of each animal in their catalogues and on-screen during the sale. Mr Sibley adds: “If they were brave enough to promote more openness about herd health, it would really give the industry enough critical mass to make it work.”

Rob Venner from Greenslade Taylor Hunt, agrees that auctioneers do have a part to play. “Breeding stock catalogues already contain a lot of information about the animals’ health status, he says. “It’s quite easy – and common – to include the information in a catalogue sale. There isn’t so much demand at store sales, but it is something we’re looking to develop.”

The electronic screen at Sedgemoor market, Somerset, is already packed with as much information as it can carry, including lot numbers, breed, sex, farm assurance and TB test dates. So Mr Venner plans to replace it with an upward projector, which will be able to carry more health information.

“Of course, being accredited for herd health isn’t a guarantee that the animals won’t later go down with disease, but it is a good guide. And we are seeing a significant premium paid for animals with good health provenance. The more information there is, the more confidence buyers have, which can add several hundreds of pounds to the end price.”

Johne’s control in the Netherlands

The Dutch dairy industry has been pivotal in driving a national Johne’s monitoring programme which makes regular testing obligatory across the sector.The initiative was set up four years ago.

Now, 70% of producers are classified Johne’s-free, with anyone failing to get on top of the problem potentially having their milk rejected by their processor.

When all cows are negative, a herd will move to a two-year testing programme and when any animals are identified as positive, the herd must be tested annually. Any positive individuals must be culled out of the herd.

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