A low cost and low input approach to flock management does not equate to lack of attention to detail when it comes to flock health planning for farmer and vet Joe Henry, of Raburn Farm, Thropton, Northumberland.
Raburn Farm runs to 93 hectares (230 acres), mostly in 24ha (60-acre) blocks, on grazing licence over a five-mile area, so careful planning and management are crucial.
Joe Henry, who also practises at Black Sheep Farm Health based in Rothbury, says: “All land is classified as Severely Disadvantaged and, as we graze a fair number of sheep on it with no housing, planning the grazing to minimise worm burden and count is essential.”
Mr Henry’s 280 ewes lamb outdoors at about 152 metres (500ft) above sea level from mid-April and about 1.66 lambs are reared per ewe. The Raburn flock started with Hampshire Downs, as Mr Henry felt the breed did well off forage and has small, hardy lambs which grow quickly, producing good quality meat, with finished lambs usually achieving U and R3L classifications at 19-20kg.
A small pedigree Hampshire Down flock is maintained and New Zealand Romney genetics were added to the 200-strong commercial flock to capture their natural good mothering traits, growth rates and vigour.
Mr Henry says: “We need hardy lambs which are capable of surviving in some pretty challenging conditions and are able to convert relatively poor quality grass into growth effectively. The breeding strategy that has been followed so far seems to deliver on that. With no payments on most of the land, it has to stack up financially.”
Part of the management policy on-farm is that lambs are weighed regularly to check everything is in order, and lambs are sold deadweight from the end of July/early August.
Mr Henry says: “Good health management is vital to allow lambs to be fit and well, eating and growing well. As a lot of our pasture is used all year-round with all grass wintering and no silage aftermaths, the worm burden could quickly climb affecting flock performance. We are fortunate to now have a small herd of 40 cows which follow the sheep, but being aware of worm challenge at all times is essential for a system such as ours.”
Routine faecal egg count testing is undertaken around lambing and periodically through the season to monitor the situation.
Mr Henry says: “Depending on results, we usually dose a few of the leaner, less thrifty looking ewes pre-lambing.
“We also use ZOLVIX™ [monepantel] on any ewes or rams brought on to the farm as a farm protection dose and one element of the quarantine strategy. We also dose pedigree, forage only, high EBV-recorded Hampshire Down shearlings we sell at our on-farm tup sale, as well as giving them an injection of moxidectin.”
In late September, any lambs left, including ewe lambs, are dosed, as by that time in the season they have often had two to three doses of wormer.
Mr Henry says: “Any worms they are carrying will be resistant ones, which we do not want shedding their resistant eggs over the pasture through the rest of autumn and winter.”
For all sheep farmers, whether on rich lowland pasture, or rough upland type like Mr Henry, managing the worm burden, both in the host sheep themselves and in refugia (on the pasture), is key to ensuring optimum weight gain and a healthy, thriving lamb crop.
Elanco vet Fiona Hutchings says: “As lambs grow and we look ahead to mid-summer, it is fair to say that, on most farms, lambs will have received at least one treatment with one of the wormers from either the white [Group 1-BZ], yellow [Group 2-LV] or clear [Group 3-ML] groups. While this is fine, it will mean on many farms a population of resistant worms will remain within the lamb.”
Advice is that mid-late season is a good time to use monepantel as a break dose to remove any resistant worms which have survived previous treatments and ensure lambs can perform to their potential.
Monepantel kills economically significant roundworms and will remove resistant worms other wormer treatments have left behind. As with all wormers, we should follow SCOPS advice and not dose= and move lambs to clean pasture.
Ideally, lambs should go back on to the pasture they were previously on for a few days, or 10 per cent of lambs should be left treated.
“The ZOLVIX™ countdown clock has been designed to illustrate how to incorporate this particular wormer into your flock management as needed, at certain times of the season,” says Mrs Hutchings.