Wiltshire organic dairy farmer Dai Wilson ensures all first season grazing calves go out into fields that have not had cattle the previous 12 months. The clean grazing policy at Starveall Farm, Bishopstone keeps any potential worm populations to a minimum, saving time and money in products and administration.
“We haven’t had liver fluke or roundworms for years, and we have had to treat for lungworm twice,” says Mr Wilson. “I believe keeping to a clean grazing plan has played a significant part in this.”
Not from a farming family, Mr Wilson started his own spring calving dairy herd three years ago on a contract farming agreement with his landlord, running 260 British Friesian cows on 204 hectares of permanent pasture. The cows are producing 5,000 litres of milk/cow which is sold to Omsco.
The cows are mob-grazed, going into a paddock when there is 4,000kg dry matter (DM)/ha and moving out a day later. They do not return to that part of the field for up to 50 days.
“We used to have 600 ewes and their lambs on the farm which helped provide cattle-free grazing. But they have now gone, sold to buy some of the cows. Things will be tighter in future, although we are not heavily stocked.
“Heifers and steers in their second grazing season are put in any field – they are old enough and strong enough to overcome any worms they encounter. I tend to move these on to fresh pasture every three days.
“Now we have no sheep it might be trickier to get all the clean grazing we need, but we can make more use of silage leys and other crop rotations. If we ever had to put young calves in a field that has cattle in the past 12 months, we would watch them closely, test them if we felt concerned and treat them, but only if needed.”
The clean grazing philosophy was put in place with the help of vet Ed Bailey from The George Veterinary Group based at Malmesbury. In the past two years, Sophie, Dai’s wife, has qualified as a vet and now works with the dairy cattle.
Mr Bailey says he ensures all his clients carry out a risk-based health plan. If farmers have had problems in the past, a more aggressive stance is taken, usually conducting dung tests four to six weeks after turnout to check primarily for roundworms.
“We encourage the use of a lungworm vaccine at turnout for dairy farmers who are autumn or all-year calving,” says Mr Bailey. “Unfortunately, Dai’s calves are too young to treat then as they are spring-born.
“In this case it is really important that the farmer listens out for any coughing when the calves are out grazing. Dung samples can be tested from batches where coughing is heard, although this is not very sensitive to lung worm. If needed, giving a drench of a Group 1 or Group 2 product is the treatment of choice for organic farmers. Conventional farmers could also choose a Group 3 pour-on product.
“The way Dai manages his grassland most definitely prevents problems. Grazing calves on fields that have been cattle-free for 12 months, close monitoring and introducing plants such as chicory and Birdsfoot Trefoil, which have natural anthelmintic properties, all help.” For more information on strategies to combat roundworms, lungworm, liver fluke or ectoparasites in cattle, visit the Control of Worms Sustainably (COWS) website.
