Matthew Blyth runs a flock of 1,000 Lleyn and Lleyn-cross ewes at Didling Farms, West Sussex. The farm is just under 500 hectares, with 170ha available for grazing. This includes 84ha of permanent pasture, 30ha zero input grass, 42ha low input grass with the remainder made up of five year and clover leys. Mr Blyth has been operating a rotational grazing system for around five years which, he believes, has helped with pasture productivity and the level of worm challenge. A small herd of cattle follows the sheep to help with this.
The flock lambs indoors, with the vast majority lambing in a tight, three-week block.
“We strive for optimum lamb growth from the pasture we have available,” explains Mr Blyth. “This means we need to ensure good grass as well as making sure lambs are able to efficiently convert what they eat into growth rates. A heavy worm burden would affect this, so we plan our wormer strategy at the beginning of the season and check worm levels using FECs.”
As someone who has to bring sheep onto the unit occasionally, Mr Blyth operates a quarantine system to ensure he’s not allowing resistant worms to get into the flock.
“We use Zolvix as part of a quarantine treatment for all sheep coming on to the farm. We do try to minimise the amount of bought in stock but those we do bring in this year will be treated with an orange wormer and an injectable for scab on arrival and then housed for 48 hours before being turned out on to dirty pasture. This will ensure no resistant worms are imported onto the farm,” Mr Blyth says.
Anyone bringing new sheep onto the unit, or moving animals back onto the farm should carefully quarantine them, ensuring they are put straight into a separate yard or housing area on arrival. Sheep should be weighed and drenched carefully with one of the newer wormers (e.g. Group 4 AD Zolvix) to remove any resistant worms that are in the sheep. In addition, a treatment for scab is advised. Sheep should not be turned out for 24-48 hours and, when turned out, that should be onto ‘dirty’ pasture i.e. pasture that has had sheep on that season just in case any missed worms are excreted.
“I think a lot of farmers are guilty of overestimating how effective certain actives and treatments can be when, in reality, resistance to the white, clear and yellow wormer groups has reached high levels. It is not too late to slow the development of anthelmintic resistance down on most farms. By acting now and incorporating the newer actives as strategic doses it’s possible to safeguard the future of worm control on your farm,” Mr Blyth concludes.