|Source: FWi||12 April 2005|
|The NADIS disease forecast is based on detailed Met Office data, and regional veterinary reports from 37 farm animal practices and the large animal units at six UK veterinary colleges.|
NADIS data can highlight potential livestock disease and parasite incidences before they peak, providing a valuable early warning for the month ahead.
NADIS disease forecasts are written specifically for farmers, to increase awareness of prevalent conditions and promote disease prevention and control, in order to benefit animal health and welfare. The forecasts are based on national trends and farmers are advised to discuss their individual farm circumstances with their veterinary surgeon.
The spring calving period is well underway and NADIS vets are seeing 50% more calving problems than average. The number of caesareans is also very high with oversized calves being the most commonly reported reason.
Last year the number of caesareans undertaken by NADIS vets was 40% higher than in 2003, which suggests that the high levels reported in April are likely to continue. Get together with your vet to work out a plan to minimise the problems with difficult calvings.
Even with low milk prices, it makes economic sense to get vet assistance early in bad calvings rather than waiting until all including the cow are exhausted. This usually leads to, in addition to a dead calf, a cow that never produces properly.
Abortions have been higher than average so far this year, with several NADIS vets reporting abortion problems due to leptospirosis (lepto). As well as being a significant cause of abortion the bacteria which cause lepto can also infect humans, often producing a severe flu-like disease which doesn’t get better.
Vaccination of cattle, as well as preventing abortion, can significantly reduce the risk of lepto spreading to humans, as vaccinated cattle are significantly less likely to have bacteria in their urine (which is the main source of spread to humans), particularly if vaccination starts in calves. If you have cattle you should know their lepto status and have a plan for its control. Ask your vet for advice on lepto prevention in cattle and humans.
Many of the risk factors for lepto, such as natural water sources and contact with sheep (or areas where sheep are grazed), are encountered only after turnout. It is thus important to ensure that your lepto vaccination is up to date as soon as possible after turnout.
Alongside the rise in calving problems and caesareans, there has also been a significant rise in downer cows and post calving paralysis. These problems accounted for 10% of all lameness cases seen by NADIS vets. Better bull selection, particularly in heifers, is likely to be the best preventative method for such problems.
The relatively mild weather in most areas of the country has meant that most cattle have seen some pasture and that the levels of lameness problems such as white-line disease and sole ulcer have been around average and foul-in-the-foot and digital dermatitis have below average. However if wet weather takes over significant problems could occur, particularly in cows that are being buffer-fed indoors.
With more cattle being grazed for longer now is the time to look at cattle tracks. We may not walk our cows as far as they do in New Zealand but research there has shown that it’s the quality of the track not its length. A badly maintained track is likely to lead to problems even if it’s short. Make sure your tracks are wide enough for your cows and that the surfaces drain well and are properly compacted down. Time spent now maintaining cow tracks will save significant time and money treating lame cows later in the year
The number of mastitis reported by NADIS vets increased last month. The main cause of the rise was a rise in toxic mastitis cases, suggesting, as was the case earlier in the year, that on many farms clean dry accommodation for dry cows was at a premium. The NADIS figures show that toxic mastitis is less of a problem in late spring / summer, however it is still a significant problem on many farms, and, because each individual case costs well over £200, it is well worth ensuring that your dry cows are maintained is as clean and dry an environment as possible.
The rise in cases of metabolic disease reported by NADIS vets wasn’t as high this April as last year. This was because neither milk fever nor grass staggers cases were above average unlike last year. Displaced abomasums (DA’s) didn’t increase as much either, however the number of reports was still almost three times the long term average. We are still nowhere near identifying what has caused this rise.
The number of cases of hypomagnesaemia (grass staggers) began their seasonal increase last month. Prevention is the aim for hypomagnesaemia; cows cannot store magnesium so need a daily dose. There are a range of magnesium supplements available; ask your vet for advice as to what is best in your situation. It’s also important to remember that fertiliser usage on grass, in particular the use of potash, depresses magnesium uptake and utilisation by both plant and animal. Don’t use these pastures in the early grazing season.
Problems with fluke have persisted this year in wetter areas. Action needs to be taken soon to try and reduce the number of infected snails on the pasture. In infected areas all susceptible livestock should be given a dose of an adult flukicide to stop eggs being laid onto the pasture. Now is also a good time to plan your control strategy for the coming winter.
Fertility problems were relatively common in heifers last month. The average pregnancy rate in beef heifers was less than 50%. On several farms pregnancy diagnosis is left too late, so that there is no chance of sorting out any problems (if their causes can be identified).
Lameness was still high in this age group in April, with problems caused by many different factors. Lameness in youngstock is as important as that in adults, preventing lameness, and treating it quickly and effectively, in growing cattle can significantly reduce the development of lameness in adult cattle.
Metabolic problems have also been common in this age group with ketosis and displaced abomasums being more common than usual. As in the dry cow, for the late pregnant heifer the emphasis has to be on getting ready for the massive changes that occur around calving.
Wormer resistance in sheep gutworms has been much in the news. However, cattle worms have been neglected, probably because, except for fluke, wormer resistance isn’t a significant problem. But it inevitably will be, so plan your grazing / worming strategy to minimise the development of resistance
The number of calf problems seen by NADIS vets increased in April. Scours was the most commonly reported problem with coccidiosis being more common than usual. These scour problems are likely to be the result of the build-up of infection over the winter, with calves affected at or soon after birth.
Control needs to be aimed at the calving areas as wells as the areas the calves are housed. If possible calve the cows in a different area. If this not possible, cleaning, disinfection and re-bedding are essential. For coccidiosis it is important to check that the disinfectant is effective against the coccidial oocyst as this stage of the parasite is very resistant to disinfectants
Copyright NADIS 2005 www.nadis.org.uk
While every effort is made to ensure that the content of this forecast is accurate at the time of publication, NADIS cannot accept responsibility for errors or omissions. All information is general and will need to be adapted in the light of individual farm circumstances in consultation with your veterinary surgeon
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