Parasite Host Balance

After a slow start internal parasites have had a good year so far. There is a constant battle going on between a parasite and its host. It is not possible to eliminate parasites completely, what we need to do is to manage them so that they will not have an impact on either the health or the production of your livestock. During the winter parasites are restricted by low temperatures, larval stages will not be active at low temperatures. It is in the spring and early summer that most infestations occur. Larval levels are high on the grass as temperatures rise and the fields are moist. The strategy for many strongly worms is to sit out the winter as an egg and only hatch when temperatures are suitable. Nematodirus is so happy with this strategy that all of the eggs passed by lambs onto pastures throughout the year wait until one single hatch on March and April. Most of the other strongyl worms also take advantage of the prevailing weather conditions.

Dry Conditions

In dry spells sheep and cattle get a break from the parasite challenge because the larvae are trapped in the ground. This summer this has not happened so most pastures will be swamped with worm eggs and the build up will continue for the next two months. There is a complexed relationship between the parasite and its host. Most of the worm eggs and larvae that are ingested will not get established inside the host animal. If the host has been challenged before the larvae will trigger an immune response to reject the parasite. Young animals, individuals that are in poor condition or under metabolic stress and those whose immune system in compromised by other diseases are the ones that are most likely to show signs of disease when there are a lot of eggs on the pasture.

Strategic Worming

Sometimes it is possible to spot the ones that are struggling with parasites. Animals that are not doing as well as they might and ones that are scouring. If most of the group seem to be doing alright you might be able to go through them now and dose just the smaller ones in the group and those that are in poor condition. Worm treatments are expensive and at this time of the year it is possible to make savings by strategic dosing as it is more important to dose the whole group in November when the parasites on your pastures will become dormant for the winter.

Thank you for your patience.

The company that make the Ubro Yellow Milking Cow tubes are still working on the product and are confident that it will return next year. Farms that use this tube, it used to be called Leo Yellow, are finding it difficult to find a replacement that is as reliable as Ubro Yellow. It has a different spectrum of activity to most of the available tubes so the hope is that when it does eventually return it will prove to be useful once more as it has been out of production for far too long.

New Tuberculosis Legislation

The Welsh Assembly Government is again leading the way with its animal health legislation. At the moment they are drafting legislation to control Bovine Tuberculosis in alpacas. Llamas goats and deer. They are concerns because the incidence of TB in camelids and goats is rising and there are fears that unless there are some monitoring and movement controls they will transmit the disease back to cattle. They proposal is to develop a system of permanently marking alpacas, llamas and farmed deer, goats are already ear tagged in the same way as sheep. The legislation will make it a requirement for owners and veterinary surgeons to notify the Welsh Assembly Government if Tuberculosis is suspected in these animals so that testing can be carried out. At the moment there is no requirement for isolation and movement controls of diseased animals. This needs to be changed as these animals are often moved over long distances and no account is taken of their health status.

Deer with Tuberculosis

It has long been known that deer are susceptible to tuberculosis and there was a formal testing scheme at one stage but that has not been carried out for a long time now. It is not thought that deer play such a big role in the transmission to tuberculosis to cattle as recent research seems to indicate that the overall risk to cattle from deer with bovine TB is less than the risk posed by badgers. In many areas of the country, and in some parts of Shropshire, deer roam freely and visit grassland at night so it would not be practical to either test them or restrict their movements.

Wider Aspects

Although this is proposed legislation relating only to Wales it is important because it will have implications for animals moving into Wales and it will help to stop the spread of tuberculosis from that country. In many ways it is ridiculous to have different parts of the United Kingdom treating animals in different ways as there are no border controls. It is difficult to see how it will be monitored if it is not eventually introduced to the whole of the UK.

Up in Scotland the proposals are to relax some of there Tuberculosis controls for Cattle. Scotland is more or less free of tuberculosis except for introduced animals which must be both pre movement tested then tested again once they have been in the country for sixty days. They try to restrict the movement of imported cattle in Scotland. When there is an outbreak it is no longer necessary to test cattle on adjoining farms provided there is no possibility of nose to nose contact with neighbouring animals.

Cattle Tracing Tests

Less than a year ago DEFRA re organised their system for doing tracing tests from Worcester to Stafford. This caused all sorts of problems at first as often test requirement were duplicated. Now they have changed the system again as the tests are administered from Cardiff. Tracing tests are undertaken if there has been a herd breakdown. All of the animals that have been on the holding that are still alive are tracked down and tested. This can be frustrating as it does not seem to take into account any previous testing history or the testing schedule of the farm where the animals are now held. Sometimes they ask for animals to be tested after a specific time. One testing request for animals on a farm that I did a clear tracing test on a cow last week arrived today. It is asking for two animals to be tested in ten weeks time. Keep a close eye on the letters that come from Cardiff, some of them might need to be filed behind the clock for a while before you need to do anything about them.

Free Ink

We have a new printer at the surgery so I have a small quantity of ink from the old canon printer which will work in Pixma ip4200, ip4300 and ip4500 machines. Please let us know if you can use this ink as it would be a shame to waste or recycle it.

Return to Newsletters