Why feeding swedes is cheapest for wintering sheep

Grazing pregnant ewes on swedes is proving the cheapest winter feed system at a Welsh upland farm at less than half the cost of feeding silage and concentrates.

Rhidian Glyn wintered 880 improved Welsh Mountain ewes and 120 ewe lamb replacements on three different systems at Rhiwgriafol, a Farming Connect Demonstration Farm near Machynlleth:

  1. silage and concentrates
  2. tack grazing
  3. and, for the first time, swedes (see table for more details).
sheep on swedes

© Debbie James

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Environmental considerations were a reason for planting three-and-a-half hectares of swedes – the farm has joined Glastir, which restricts winter grazing on hill land and this created a feed gap.


Feed allocation

Ewe numbers


Land allocation


10 bales of silage and 27kg concentrates/per head


(Silage analysed 44% DM, 10.3ME and 14% CP).

205 yearlings

1 Jan – mid-March





425 ewes

Early October – early/mid March

*Twins return home early March followed by singles later



Swedes – dry matter yield of of 10t DM/ha


249 ewes

1 Jan to end of March *Twin bearing ewes taken off crop on 4 March


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As part of his Farming Connect project work, all three winter feed systems were analysed and costs compared by Catherine Nakielny, Mid Wales Red Meat Technical Officer at Farming Connect.

Farm facts

  • Farms 212ha at Rhiwgriafol and rents 30ha south of Aberystwyth
  • 450 of the youngest and best ewes to a Welsh Mountain ram for breeding replacements
  • Another 430 are bred to an Aberfield or Texel cross Bluefaced tup
  • 120 ewe lambs are mated to New Zealand Suffolk rams

Because each group was different sizes costs were calculated on a per head basis.

  • At £7.83/ewe, the swede crop emerged as the cheapest
  • Grazing winter tack costs £10.90/ewe
  • Whereas feeding silage and concentrate was most expensive at £16.72/ewe

Fifty-five acres were allocated to this group of 205 yearlings. Once the impact this had on spring grass growth was taken into account, the cost of this feeding system doubled.

For the swede crop, the equivalent cost of taking the land out of production is £1.50 per ewe, or 20% of the total costs.

What the costs included

Costings included concentrates fed when the ewes were taken off the swedes ahead of lambing and the time and fuel costs associated with regularly checking ewes on winter tack.

Labour requirements were also taken into account plus an allowance for the rental value of any land used. This substantially increased the cost of out-wintering the yearling ewes on grass with concentrates and some silage.

Cost comparisons for Rhidian Glyn’s winter feed systems


Feeding system


Winter tack

Home-grazing with silage and concentrates

Swede crop









Silage and concentrates




Forage crop costs












*non-cash costs

Crop establishment

The swede seed variety was drilled in June at a rate of 1kg/acre.

The land at Rhiwgriafol is a silty loam and relatively free-draining. Mr Glyn selected a field that was not too steep and had a grass runback of seven acres to avoid issues with run-off.

The field had been earmarked for reseeding because the quality of the grass ley was poor with a high weed burden. The field was treated twice with glyphosate before the seed was drilled.

Feeding strategy

Mixed aged ewes were turned on to the crop on 1 January and the fence moved every three to four days. After scanning in mid-January, both singles and twins were returned to the swedes.

Silage was also offered as a protein source because swedes are high in energy but low in protein. Only six bales were used in total.

Twins strip-grazed the crop until 4 March – three weeks before lambing – when they were housed and fed 400g of an 18% concentrate and silage.

Singles remained on the crop until just a few days before they were due to lamb and fed 200g of concentrates for the final 10 days.

Mr Glyn also contract rears dairy heifers, which creates pressure on shed space pre-lambing and sheep are housed as late as possible.

“We only house a couple of days before lambing because there were 93 heifers in the sheds until then,” says Mr Glyn.

All ewes were given a bolus containing cobalt, selenium and zinc in October. Iodine supplementation was given via mineral licks. 

Stocking densities

At 249 ewes, the swede crop was understocked but there was good reason for this. “I didn’t want to put the young or older ewes on it because of potential problems it could cause with pulling their teeth forward and any tooth damage could allow a route of entry for the listeria bacteria so I narrowed it down to 249.”

This meant at lambing there were 1.2ha remaining but, with grass often in short supply in April, Mr Glyn says this would provide useful feed for ewes and their lambs.

He aims to graze this year’s planted crop earlier, on 1 December, to avoid this situation next year.

Mr Glyn will repeat the process of measuring the crop before making a final decision on when to start grazing next year.

Advice for feeding swedes

Swedes are a good main crop for winter feeding because they provide low-cost, high-energy feed and they also enable good use of land in crop rotations.

Dr Nakielny advises a flexible approach to winter feed systems.

“It doesn’t need to be based around the same system every year, farmers must consider what is going to suit the farm in each year,” she says.

“It’s also possible to combine various options for risk management to avoid situations like crop failure in a system that relies only on winter forages.”

Although the silage and concentrates combination is the most expensive, cutting grass for silage can be a good means of managing grass quality during the growing season.

Grassland use and maintaining mid-season quality is something which is also being highlighted through a number of Farming Connect projects taking place this summer.

“There is a place for feeding silage strategically during the winter months as it can help manage excess grass growth in early summer and can also help buffer grass supplies over the winter,” says Ms Nakielny.

A potential disadvantage of growing forage crops is the length of time a field is out of grass production.

At Rhiwgriafol, the field was taken out of production at the end of May 2016 and, following the crop with a permanent pasture grass ley, means that it won’t be available for grazing until the end of June 2017 following the reseed.

“It is not cost effective to plough up a good grass field but if you are replacing a poor grass ley with a much better one then it is a good to use it as a break crop in the rotation, not least to avoid potential problems with leather jackets and other pests associated with grass to grass reseeds,” Ms Nakielny advises.

Fields need to be carefully selected to provide shelter, water and a loafing area and water quality must not be compromised by run-off. Steeper fields should be avoided.