Do you occasionally find a young animal or worse perhaps a cow dead on a field? Are you surprised sometimes perhaps to find out how fast the carcass gets bloated and goes rigid? There are several things that can be responsible for sudden deaths in cattle, by far the main reason is blackleg. This is a bacterial infection that multiplies in the soil and starts up an infection in the gastro intestinal tract of your cattle. Blackleg can only cause disease if there is a build up of the infection in the gut or if the animal sustains minor muscle damage from being bullied or damaged by an animal with horns. There are few farms that are not affected by blackleg at one time or another. There is an effective vaccine that works with just a single dose. This should be repeated each year stock is put at risk. We have seen an increase in the number of confirmed cases of blackleg this summer and I suspect there are others that have not come to our attention. I think the problem will continue into the winter this year.

Pfizer report that they are having difficulties with their 100ml bottles of Synulox RTU injection. Because of this we have moved over to Nisamox Injection for a while. This has exactly the same concentration, so it is still a 30 ml daily dose for a cow and the milk withdrawal time remains at 60 hours. I am not sure why drug companies have supply problems with their established products from time to time. It is not a good thing when you get used to knowing what a drug can do and then have to cope with a different product that has different properties and might have different withdrawal times.

Intervet have now declared that they are unable to supply Toxovac for the rest of the year. This year Deccox will be the only treatment option if you have problems with this disease causing abortions at lambing time. Trying to treat the disease after you have got it will do little to reduce the infertility problem which is the more usual manifestation of the infection. Toxoplasma is a parasite carried by cats which can readily contaminate feed and fodder for the pregnant ewes. They can also come into contact with the infection from fields that cats defecate on. In theory it should be possible to avoid Toxoplasma by keeping cats away from feed stores and getting the pregnant ewes to graze away from the buildings where the ground should be cleaner. This does not always work in practice so it is particularly disappointing that there will be no vaccine available until next year.

Most dairy farmers will have had a leaflet from DEFRA concerning Johne’s disease. This is a chronic wasting disease of cattle that is caused by Mycobacterium avian para tuberculosis, this is usually shortened to ‘Map’. There has been a steady increase in the numbers of animals diagnosed with Johne’s disease. It seems to be occurring in younger animals now and is a cause of concern because of the association with Crohn's Disease in man. As far as I am aware Johne’s disease is not a big problem for dairy cows in our part of Shropshire. It has a tendency to affect cattle that have suckled a cow. The disease develops only slowly and is not normally seen in animals less than three years of age. It is now thought that most animals that carry Johne’s disease catch the infection as a calf. If you have the infection on your farm it is in the faeces of adult animals. New born calves pick it up from contaminated teats or contaminated calving boxes. The advice is to rear calves in an environment well away from anywhere that adult animals have access to or where manure or slurry has been spread. They suggest that there should be a gap of twelve months before calves going onto these potentially contaminated pastures. Sheep can also act as passive carriers of Map so they too must be kept away from young calves.

Clearly it is very difficult to control this disease. You might get involved because eventually you may have to demonstrate in your Herd Health Plan that you have a strategy to prove that you do not have Johne’s disease in your herd and that you are able to stop it spreading. There are blood tests that can be done on the older cows, but to get relevant results samples should be taken at least annually. I can well understand the reasons for reducing the incidence of Map in dairy cows to safeguard public health. It is a shame that DEFRA has not found a way to fund the control measures or at least subsidize the cost of the laboratory fees which are substantial at the moment.

As time goes on the farm Herd Health Plan will become more important. It is government policy that all farms must have a Health Plan by 2014. Certainly the National Dairy Farm Assurance Scheme has been stepped up a gear to broaden the things that are monitored and to bring it more into line with the beef farm assurance scheme.

The sections of the plan that have been changed are the biosecurity measures and controls of infectious diseases. They ask for concise details on the management of downer cows and protocols for the management of Casualty Animals and for the disposal of Dead Stock.

There are new sections on how calves are disbudded, castrated and have their supernumerary teats removed and you will need a written policy now concerning how you will ensure that your calves receive adequate quantities of colostrum. Another new section concerns procedures to ensure that broken needles and other foreign material are not able to contaminate meat.

All farms are assumed to have a good standard of biosecurity and measures to clean and disinfect vehicles and clothing will now need to be included in the Farm Health Plan. There are suggestions that it may be appropriate to maintain a record of all farm visitors and provide them with protective clothing. I do not think this is necessary on most dairy farms as it is meaningless if you have public footpaths that cross your land or if your stock cross roads to get to their fields. I have been writing Herd Health Plans for three years now and can easily adapt one to suit your needs.

There is more information about Herd Health Schemes on the NDFAS site. Be careful there are 109 pages in the revised October 2004 version so do not print it unless you really want to go through the details of all of it.

You may have had to treat your young stock more frequently than normal for roundworms and lungworm this summer because of the wet conditions. It is often advisable to use a pour on wormer at this time of the year because they are also able to stop lice and mange getting established on your stock in the winter. Most pour on wormers have a persistent action and can be used for up to four weeks before the animals are finally housed.

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