Reducing BVD and Johne’s Disease risks at calving

Where disease is already present in a herd, it is important to reduce the risk of it circulating.

Calving time is a critical period when Johne’s Disease (JD) infects calves, so it is important to minimise contact between newborn calves and manure from adult cattle that might have JD bacteria present and to avoid calves taking in infected colostrum or milk.

Farmers who have had BVD infection in their herds in the past year are advised to be prepared to act quickly if further BVD Positive results are returned, so that the risk of infected material being transferred within their farms or to other farms is minimised.

Some measures that should be considered around calving are as follows:

1. Calve Johne’s Disease positive cows away from where the other cows calve and don’t use colostrum or milk from any positive cow to feed other cows’ calves.

2. Aim to have cows and heifers as clean as possible as they enter the calving area, for example, by clipping tails to reduce the amount of faeces present on the tail, flanks and teats. Ideally try to have the cows on straw bedding coming up to calving, to improve hygiene levels.

3. Keep the number of animals calving at the same time in the same pen to a minimum, to reduce the risk of newborn calves being exposed to several cows, their dung and their milk.

4. Make sure that calving pens are regularly cleaned and disinfected; ensure that sufficient bedding is present so that cows are calving on to a clean and dry surface. Calving pens should not be used as hospital pens for sick cattle.

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BVD vaccines act to protect the developing foetus from infection with the BVD virus across the placenta.

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5. In dairy herds that are known to have JD present, remove all calves as soon as possible from their dams to reduce calf contact with adult dung and place in a well-bedded calf box or pen.

6. Treat calves’ navels as soon as possible (making sure that you can safely handle the calf, away from the cow), and ensure that adequate colostrum is consumed within two hours of calving (using three litres from the first milking.)

7. While the calving season is a particularly busy time on many farms, herd owners are encouraged to tag calves promptly after birth (as soon as the calf is dry). Calves that are tested when they are older may have contacted a BVD virus Positive animal and therefore may have a transient infection which will show up as a Positive result and mean that a retest is required.

8. Send samples to the laboratory quickly. If ear tissue samples are being stored in a fridge before being dispatched to a laboratory, they should be stored for no longer than seven days.

9. Keep calves of unknown BVD status away from pregnant animals and act quickly to strictly isolate calves if positive results are received. Persistently Infected calves should be culled at the earliest opportunity.

Stillbirths or weak calves can be a result of infectious disease, so if necessary discuss appropriate strategies for investigating these, such as blood testing and vaccination, with your vet.

While many vaccines are given well in advance of calving, so that adequate antibodies are present in colostrum, BVD vaccines act to protect the developing foetus from infection with the BVD virus across the placenta.

Check individual vaccine data sheets and discuss your herd’s vaccination protocol with your vet: in general, the vaccination course (either two shots four weeks apart or a single shot) should be completed three to four weeks before the breeding season. Booster vaccinations should be given according to the specific instructions.

Do plan ahead and keep SAFE.