Newsletter January 2002

KEEPING BUSY
Welcome to our fourth Newsletter. Most OLA members have had their herd screen tested for BVD. Following the results of this, many whole herd tests have been carried out during the past few months.

For those of you who have not yet joined OLA, or for members who have not had a screen test carried out, let us remind you that now is the time to get underway. The funding package we were given by Orkney Islands Council will only be available to you for the next two years - this money saves you 75% of the usual cost of having your whole herd tested, should you have a positive screen test.

It has been very encouraging to see groups of neighbours joining together in an effort to keep their area and cattle BVD free.

BULL SALES
We hope you will support the Orkney Bull Breeders Association sale at the mart on Friday 1 February 2002.

To clarify some questions we have been asked regarding the purchase of a breeding bull when you are taking part in our BVD eradication programme, here are some useful points to consider: -

1. When you buy a bull from a sale, take it home and keep it separate from the rest of your herd for three weeks. It is a major health hazard to mix newly bought-in stock with your existing cattle - not just for the sake of BVD, but for any other viruses they may be carrying.
2. If you do not know the BVD status of the bull, get it tested. If you have purchased a white or green animal, you should have no worries (as long as you follow point 1 above). If the bull is a white animal, you should vaccinate it.
3. It is unlikely that you will purchase a breeding bull which is "red" (referring to status - not colour)! If you discover that this is the case, you are entitled to return it to the seller of the animal for a full refund plus any expenses, if the animal was purchased from a specialised breeding bull sale.

WHITE GREEN & RED
There still seems to be some confusion as to what animals are "safe" to buy-in.

1. White animals are no cause for concern, but as they have no natural immunity against BVD, any that are being kept for breeding purposes would be protected if they were vaccinated.
2. Green animals have natural immunity to BVD as they have been in contact with the disease at some time and do not require vaccination. Green animals are no cause for concern, unless they are in calf. Pregnant green animals may be carrying a red calf. (See our December Newsletter - Issue 3).
3. Red animals are born red. When a white cow comes into contact with a red animal in the first half of pregnancy, she becomes green and the foetus inside her becomes red. If this foetus survives to the point where it is a live calf, this calf can spread BVD amongst other calves, lowering their immune system. Any health problem that enters the herd at this point could cause an epidemic, resulting in rounds of antibiotics and losses. If this red calf survives long enough to go out to grass with its mother and the rest of the herd, it will spread BVD to all or most of the other cattle in the field, or any neighbouring animals over the fence. These animals will turn green, but as we explained, the unborn calves could turn red, and so the problem continues and intensifies.

GRAZINGS
Thinking ahead now! Please consider your herd's health status if you graze your animals away from home on rented pasture. There may be many animals from different holdings across the fence from yours, and they may be from holdings that have not taken part in the BVD eradication scheme.

In the future, it may be that land is not offered for let unless the prospective "tenants" are involved in the eradication programme.

Until then, the best advice we can give is that it is especially important that you keep your breeding animals away from any other herd of an unknown status.

VACCINATION
If you have had a negative screen test, you must vaccinate your breeding animals and/or use double fencing to prevent BVD entering your herd. You should also remember to vaccinate any heifers you plan to keep for breeding purposes.

The vaccination process involves giving two sub-cutaneous (under the skin) injections three weeks apart for the first year, then an annual booster every following year.

You should start your vaccination programme before the cows go to the bull.

The vaccine comes in five-dose packs, costing around £10 per pack (£2 per dose).

If your whole herd has been tested, you only have to vaccinate any animals that are white.

As we reported in the previous Newsletter, Novartis, the vaccine manufacturer, is sponsoring the laboratory costs of the BVD screen test. This reduced the price to around £45 (including the visit fee). Unfortunately, this offer is only available until the end of March this year - so book your screen test now if you want to take advantage of the cheaper rate.

You should ask your vets advice regarding vaccination when you receive the results of your screen test or whole herd test.

INVESTIGATION OF BOVINE ABORTIONS by DR A M CLARK
The Orkney Livestock Association project funded by Orkney Islands Council to determine which cattle herds in Orkney have Bovine Viral Diarrhoea (BVD) through blood sampling of animals, can be backed up by the full investigation of any cattle abortions. Every herd will have one or two cows produce or lose a calf before the expected calving date. There is commonly a reason for this happening, and it is advisable to have the cause investigated by your vet. Once that is found, action can usually be taken to reduce losses and prevent further problems in the future.

Examination of the calf or foetus can not only reveal the cause, but can also help in identifying the presence of disease which could lead to production loss in the herd. BVD can cause abortion at any stage from one month after service to calves dying at calving. It is common to find abortion as the first indication of the disease in a herd. For this reason, it is advised that all abortions and stillbirths are investigated, since early recognition of BVD presence can make control and eradication easier and avoid a lot of grief! Abortion rates as high as 40% of the cows in a herd have been recorded in Orkney with BVD infection.

If you have any abortions or unexpected stillbirths, contact your vet in the first instance and also report the incident to the Animal Health Office in Kirkwall. SAC at Thurso can examine the calf that should be transported by P&O Scottish Ferries from Stromness, using special grey boxes.

For further information, contact your vet or SACVSD, Thurso.