28 August 1998

Quarantine cuts risk of disease

By Rebecca Austin

RUNNING a closed herd has advantages – but it also increases risk of serious concern when disease comes onto farm.

Basil Lowman, SACs senior beef specialist explains: "There are lots of advantages to running a closed herd. But the risk is that when something goes wrong in terms of disease outbreak, it will go seriously wrong.

"Producers must therefore pay close attention to disease control and security."

Most dairy and beef herds in this country are only semi-closed, says Dr Lowman, because, although they breed their own replacements, a bull is usually bought in for breeding.

"Again, there are advantages to semi-closed herds. However, there are important rules to obey – these cattle are naïve to many diseases because they have little or no resistance," he says.

"Open herds may buy-in disease, but at least the herds resistance is continually challenged. Therefore, semi-closed and closed herds need to be more security conscious, and ensure bought-in animals are quarantined before joining the herd."

Dr Lowman says he has yet to go on farm and find a quarantine facility which is isolated to the extent that it has separate drainage. However, he says the rules of quarantine are simple – the longer the better.

"Producers keep new stock separate for a minimum of four weeks, but only a small minority of people do that.

"All you need to do is keep new stock at least a field apart or in a different shed."

He suggests producers buying-in heifer replacements source them from one or two known herds, rather than the market. The same applies to foster calves, which can be the kiss of death to a healthy herd, he warns.

"Pneumonia is one of the biggest killers of calves and yearlings. However, we are trying to develop a new scheme where SQABLA-accredited suckler herds selling stores to finishers automatically vaccinate against pneumonia prior to moving to prevent breakdowns bought on by stress," adds Dr Lowman. &#42

HERDHEALTHADVICE

&#8226 Source replacements from known disease status herds only.

&#8226 Screen for disease on arrival on farm.

&#8226 Only buy bulls from proven herds with a health status accredited by a reputable health scheme.

&#8226 Encourage pedigree breeders to use health schemes.

&#8226 Check and secure farm boundary fences to prevent stock straying in or out of farm.

&#8226 Consider implications of humans carrying disease between farms.