29 August 1997

SECURITY NIGHTMARE…

The healthcare problems faced by one man make those of the average flock manager seem almost trivial. Robert Davies reports

THE complex structure of the 3000-ewe flock at the Welsh Institute of Rural Studies, Aberystwyth, which includes high value sheep owned by other farmers, means that effective disease control is crucial.

Sheep research project director Dewi Jones is responsible for maintaining a veterinary strategy that is as close as possible to being foolproof.

The Institutes 2000 commercial ewes are managed in association with the high index Texel national breed development flock, and Bluefaced Leicester and Beulah Speckleface group improvement nucleus flocks. Three hill ram improvement groups also send tups each year for performance testing.

Farmer members of the schemes and other breeders have to be given access to the sheep. So too must staff and students, many of whom also have contact with flocks on other farms. A tight veterinary protocol is needed to counter near-ideal conditions for the introduction of disease, and cross infection between breeds.

"I admit I sometimes find it difficult to sleep, especially at critical times like lambing," says Mr Jones. "Nothing must be overlooked, especially when, for example, maedi visna accredited and non-accredited sheep are being inseminated alongside each other, or new animals come onto the farm, or students return from a weekend at home.

"Not only must groups of sheep be separated physically, but where they graze has to be double fenced to stop contact with neighbouring animals. My real fear is of an infectious disease spreading between breeds. To minimise the risk, people who manage one group avoid working directly with another."

Scab is a major headache. Performance test rams arrive from farms that use common grazings where scab is often endemic. The rule is that all participating animals are dipped in a non-OP chemical regardless of previous treatment.

Enzootic abortion is another serious concern. Visits by students and outsiders are discouraged during lambing, and commercial sheep are bought from accredited or closed flocks. Ewes in nucleus flocks are blood tested, and wide scale vaccination would be used to control an abortion storm, says Mr Jones.

Any lame sheep arriving from outside to participate in any scheme is rejected, and routine foot care is meticulous. Animals that frequently have foot rot are culled.

"Within all the flocks the aim is to identify early disease symptoms. The expression that there is no substitute for experience is particularly relevant in our particular situation. We use past experience to construct a health programme that highlights each individual flocks susceptibility at various times of the year."

With the ANTUR Texels, dystocia, or difficult births, can be a concern. Single bearing ewes are fed concentrates with a high percentage of by-pass protein. This is utilised for udder development rather than for increasing lamb birth weight.

Texel lamb creep feeds have less copper to counter the breeds susceptibility to copper toxicity. A higher than average incidence of hard udder, probably caused by chronic post-weaning mastitis, has also been recorded. Lactating ewes are closely monitored for mastitis.

Orf, a major difficulty in commercial Bluefaced Leicester flocks, is controlled at Aberystwyth by scratch vaccination in the first two days after lambing, and quickly moving ewes and lambs out of the clean lambing shed. Ewes are wormed using a long-acting Ivomectin solution at turnout, and the creep feed used has enhanced levels of chelated zinc.

Coccidiosis-induced ill thrift is not uncommon in young Bluefaced Leicester lambs. The coccidial challenge is minimised by incorporating a coccidiostat in ewe concentrate fed during the last six weeks of pregnancy, and in the creep ration.

"Many difficulties are common to all sheep breeds and crosses, and the industry has access to well proven preventative measures and controls for clinical cases. It would be a disaster for the reputation of WIRS if we hit problems as a result of poor management, or ineffective veterinary protocols," says Mr Jones.

"My experience suggests that success depends on planning health programmes in advance, and preventing previously en-countered difficulties from reoccurring. Monitoring, good routines, and responding immediately to early warnings play a pivotal role in our system."

Mr Jones would like to see links established between farmers, abattoirs and veterinary laboratories allowing routine reporting on the post-mortem condition of key organs.n

Health care is a prime concern for Aberystwyths sheep research flock manager Dewi Jones who is responsible for maintaining a veterinary strategy which is as close as possible to being foolproof. A tight protocol is needed to counter near-ideal conditions for disease introduction and cross-infection.

HIGH HEALTHCARE

&#8226 Plan care in advance.

&#8226 Monitor flocks.

&#8226 Stick to routine.

&#8226 Respond to early warnings.