4 June 1999

How worm count really adds up…

By James Garner

ADOPTING new roundworm testing technology which can save money and labour was demonstrated at South Sheep 1999 held at Cross Farm, Wallingford.

Stephen Harts flock of 1000 ewes is run by one shepherd with lambing help in April, so time-saving devices are important.

For the past two years, shepherd Steve Atkinson has been using a faecal egg counter to improve drenching policy.

By observing lambs and taking faecal samples a week before lambs should be dosed, Mr Atkinson has found he can delay worming by two weeks on some occasions.

It is possible to do a group test by taking 10 or 12 samples or just follow an individual lamb and collect its dung.

Dung is weighed and then mixed with saline in the bag to free the eggs. Once thoroughly mixed the solution is filtered and poured into a slide chamber, which can be examined under a microscope at 40 times magnification.

Once the number of eggs are counted the degree of worm burden can be calculated. For example, 10 eggs would be equivalent to 500 eggs/g according to the scale and weight readings.

"But you have to assess this on a farm-by-farm basis. We wouldnt worry too much below 250 eggs/g.

"Its surprising how few eggs lambs are shedding at times. We also found nematodirus eggs last year and discovered a higher worm burden on two year leys than on permanent pasture." Higher stocking rates on the leys may explain this, he said.

However, he feels the faecal egg counting system, which is easy to use, will have extra value when more producers use them and experiences can be shared.

"You can check on wormer resistance by taking a test after dosing to see whether egg numbers are reduced or not. Weve had white drench resistance here for some time."

"Our policy now is to drench all ewes at lambing with ivermectin. Then lambs are dosed with ivermectin for their first dose, which is a small one, followed by levasimole type wormers."

The egg counting kit is imported from New Zealand where producers group together and share its costs. This would be a way for interested producers to use the system in this country.

WORM COUNT

&#8226 Can delay drenching.

&#8226 Accurate test.

&#8226 Group share.

WORMCOUNT

&#8226 Can delay drenching.

&#8226 Accurate test.

&#8226 Easy to use on farms.