Outwintering suckler cows on kale is saving a Strathmore farming family more than £7000 (£55 a cow) in bedding and mucking out costs, along with substantial savings in machinery, labour and feed.
Shed space has also been freed up for weaned calves and fertiliser costs have been halved on fields where the cows have been outwintered.
Ken and Margaret Durston, who farm 344 ha (850 acres) at North Nevay, Balkerie, Forfar, in partnership with their son, Andrew, have steadily increased herd numbers since 1988.
As numbers increased so did pressure on housing space. Their options, other than outwintering, were to build new sheds, away-winter cattle, reduce cow numbers or sell stores earlier.
Instead, the Durstons’ 150 suckler cows and 30 heifers are being successfully outwintered on kale and stubble turnips up to 900ft above sea level at a cost of 64p a cow a day.
The brassica crops are only given one application of poultry manure and last year kale yielded 34-30t/ha (85-100t/acre), explains Andrew, with the residual fertiliser value resulting in considerable fertiliser cost savings for the spring barley crop to follow.
He estimates this is worth 60 units/acre of nitrogen for the following crop and about 90 units P and 130 units K (for 50 cows running on 25 acres). “Last year we got a yield of 3t/acre with a fertiliser cost of just under £20/acre, so we have halved our fertiliser bill,” he says.
There is also considerable labour saving – last year it took 1.5 hours a day to feed and check their 180 cows and heifers.
Fertility in the outwintered cows is proving good and last year saw a 92% pregnancy rate, including 17 sets of twins from 115 cows. The outwintered cows are less competitive and there is less bullying.
“Outside cows are fitter and better acclimatised. There’s no adjustment period at turnout and they tend to calve easier. We’ve noticed the disease level – in particular scour – is also lower among the calves,” says Andrew.
Most cows are Simmental or Charolais crosses with some Bazadais and the Durstons breed their own replacements. Most are put to a Charolais bull, but a Shorthorn bull was introduced last year as the Bazadais’ were proving a little thin-skinned.
“Cows are separated into three groups of 60-70 – heifers, first calvers and second calvers – to graze 14ha (35 acres) of kale for 135 days, giving a stocking rate of around two cows an acre from mid-November to early April,” he says. Heifers are housed in January and last year cows calved on the kale in April.
Minerals are sprinkled on to straw bales and magnesium flakes are added to water at a cost of 1.5p a day to minimise the risk of staggers.
The general rule is that kale should make up no more than 50% of the diet, according to SAC, and it is important to feed straw at the same time and to introduce cows to kale gradually to prevent acidosis or laminitis problems, explains Andrew.
Choice of field is also crucial, as cows require a dry area to lie and shelter, but a hollow in a field can prove as adequate as a shelter belt.
Steps have been taken by the Durstons, on advice from SAC and QMS, to avoid the tracking problems caused by taking straw bales out daily to cows.
“We have changed our system to set-stocking bales through the fields in advance on dry, frosty days. We also move the electric fence every day, which makes for a much better system and means muck is evenly spread across the field,” says Ken.
According to SAC beef specialist, Gavin Hill, the high fixed costs of suckler cow units mean there is plenty of scope to reduce the cost of keeping cows, improve efficiency and get more margin back to farmers and outwintering is an option working well for the Durstons.
However, he emphasises that while most Scottish farmers can grow brassicas well, outwintering will not be an option for every farm.