7 March 1997

Abortion risks are high when bedding damp

Prolapses in ewes and a mystery piglet disease are just some of the issues to watch out for this month. Jessica Buss reports

MYCOTIC abortions are more common in cattle at this time of year as stocks of mouldy, damp hay, silage and straw are being used for feed or bedding.

Vet Andrew Norton, Marlborough, Wilts, says that mouldy feed and bedding, that could be contaminated with the mycotic fungus, should be avoided, particularly for heavily pregnant animals. Single cases of mycotic abortion are most common but larger outbreaks can occur.

"Once an animal aborts the fungal growth on the cotyledon of the placenta is advanced and it may be too late to stop more cases within the next month," says Mr Norton. However, abortions at this time of year may also be caused by bovine viral diarrhoea (BVD), infectious bovine rhinotracheitis (IBR), leptospirosis, neospora and brucellosis.

Currently abortions must be notified to the vet for brucellosis testing. But it is also important to take blood samples from aborted cows to identify which disease is present. Vaccinations for the disease found may be cost-effective.

Mr Norton claims many producers routinely vaccinate against IBR and lepto, and a new BVD vaccine is giving an extra stimulus to identify infection.

"Animals previously infected with BVD and IBR remain carriers and shed the infections when stressed," he says.

"Lepto could also come from sheep grazing on the farm or watercourses shared with other farms." The most effective prevention of these infectious diseases is a closed herd.


CATTLE: WATCH FOR


&#8226 Poor fertility in thin cows.

&#8226 Scour and reduced yield if turned out too early.

&#8226 Continuing pneumonia in calves.

&#8226 Consider vaccination for husk, and worm first-year grazers.