Robert Atkinson standing by field of sheep

Protecting margins with targeted worming

On an intensive lamb finishing system, where every day counts, Robert Atkinson can’t afford for a worm challenge to knock performance.

Mr Atkinson buys in around 30,000 store lambs a year for finishing. Half are kept on short-keep at the home farm near Richmond and intensively fed indoors over three to four weeks. The rest are sent to local keep or into Lincolnshire, Norfolk and Suffolk for finishing.

Lambs are sourced from multiple locations, which means it’s impossible to know wormer treatment history or whether wormer resistance is an issue.

However, according to Sustainable Control of Parasites in Sheep (SCOPS), resistance to white (1-BZ), yellow (2-LV) and clear (3-ML) wormer groups is on the increase. Indeed, most farms will have resistance to one, or more commonly, two or three wormer groups.

With that in mind, it’s likely that some bought-in lambs will have some resistance, which could knock growth rates.

Traditionally, Mr Atkinson opted to dose the lambs for intensive finishing with an Ivermectin (3ML clear) wormer on arrival, together with a mineral drench sourced from Mole Valley Farmers. They would then be finished indoors. However, Matt Blacklidge, our Business Development Manager in Piercebridge, suggested such a strategy could be compromising performance if resistance was an issue.

Further discussions with Jake McRobert, Customer Development Manager for Elanco Animal Health, convinced Mr Atkinson opting for Zolvix - a new class of drench (4-AD orange) - was the right way to go. He said: “The reason we moved to Zolvix was a safety precaution – we knew there wasn’t as much resistance to Zolvix.”

Ensuring optimum treatment success would also help boost growth rates with lambs finished within the target four-week window.

Mr Atkinson said: “There isn’t enough spare room in the system to have lambs that aren’t doing. We don’t want lambs hanging around on the intensive system for five to six weeks. The profit margins are so tight; you can’t afford to have anything holding them back.”

Despite being more expensive than Ivermectin, Mr Atkinson’s calculations showed only a small amount of extra growth was needed to cover the cost. (See box)

Mr Atkinson concluded: “If we can shave even a couple of days off the amount of time the lambs are on feed, it’s paid for the wormer. We can’t afford to be feeding lambs 1.5kg /day for them not to do. I certainly value the advice of Matt and Jake.”

Farm facts:

  • High Greenbury Farm Ltd, Richmond, North Yorkshire
  • Rent about 500 acres of summer grass, including buildings and 150 acres at the home farm
  • 2,100 ewe commercial flock
  • Suffolk and Texel cross ewes lamb in January. Lambs are creep fed
  • Cheviot Mules lamb in April - Lambs are finished off grass
  • Texel and Suffolk terminal
  • Lambs finished at around 22kg deadweight and sold to Dunbia, Carnaby
  • Around 30,000 store lambs bought-in and finished every year - mix of breeds including Texels, Suffolks and Mules
  • 150 continental store cattle brought in annually and finished

Protecting against resistance in new wormers

  • To protect against resistance in the two newest wormer groups (orange and purple), they must be used responsibly.
  • The two newest wormer groups (4-AD and 5-SI) should be incorporated into worm control programmes on all sheep farms, not left until the others are no longer effective
  • There are only two occasions when a group 4-AD or 5-SI should be used; quarantine, and mid/late season as a ‘one off’ annual drench for lambs
  • They should only be used at other times under veterinary direction and only if the full anthelmintic resistance status of the farm is known
  • Best practice should always be followed

Why Zolvix adds up:

Cost-benefit from using Zolvix to treat intensively finished store lambs which are on farm for about four weeks.

Previous approach

  • Ivermectin drench (3-ML clear)
  • 12.5ml dose for 40-50kg lamb
  • 10p/dose = 2.5p/week a lamb is on farm

New approach

  • Zolvix (monepantel) drench (4-AD orange)
  • 4ml dose for 40kg lamb
  • 65p/dose = 16.25p/week a lamb is on farm

Zolvix = 13.75p/week more expensive than an Ivermectin drench.

Only need to achieve +55g of extra growth per week to cover the extra cost of the Zolvix or +220g over four weeks.mailto:[email protected]

(Figures based on a live weight price of £2.50/kg and lambs finished over a four-week period).