Project Background

The loss of the Single Farm Payment and uncertainty regarding future trade deals is a concern for the British sheep industry. Risk management and future planning is therefore a key priority for many forward thinking sheep farmers. Improving enterprise margins will reduce associated risks and one possibility is the use of cheaper feeds.

Case Study: Maximising forage and grassland utilisation by out wintering in-lamb ewes on swedes


Utilising forage swedes to out winter in-lamb ewes has been practiced in New Zealand for several years. This practice reduces fixed costs whilst maintaining high stocking rates to fully utilise both forage swedes and grass, these being two of the cheapest available feeds. Many UK farmers are now opting to use brassica crops and swedes to maximise returns and reduce associated production costs. However, little research has been conducted in recent years to assess how climatic differences may impact on the system in the UK or the nutritional requirements of ewes in the transition from swedes to grass in the  spring.


With this in mind, ADAS was commissioned by AHDB to report on the practicalities and financial aspects of adopting an outdoor ewe feeding system based on swedes and grass. Findings were compared to a conventional indoor lambing system, with lambs fed creep, on the same farm.
A range of flock management and performance records were collected including:

  • Ewe and lamb losses and animal health records (including metabolic profiles of ewes pre-lambing and FEC monitoring in lambs)
  • Ewe weights and body condition scores
  • Lamb weights, growth rates and days to slaughter
  • Calculation of lambs reared and stocking rates
  • Inputs including concentrate feed, forage and fertiliser
Housed Out wintered
Pregnancy scanning (%) 178 160
Lambs reared (%) 155 135
Lamb losses – scanning to rearing (%) 13 15
Lamb birth rate (kg) 5.0 4.8
Weaning weight (kg) 31.6 26.3
Daily gain to weaning (g) 233 204
Lamb carcass weight (kg) 18.8 19.5
Average Lamb Price (£) 73.05 74.10

Summary of physical performance across the two systems

ADAS produced full enterprise costings to compare the financial performance of the two sheep systems. The comparison found that crops such as swedes provide a cost effective alternative to housing sheep, with total costs/ewe reduced by a third and costs/ha down by half in this study. Despite fewer lambs being  reared on the out wintered system, profit before rent and finance was improved by £302/ha over the conventional system. This may be particularly beneficial to new entrants focusing on reducing fixed costs. The forage system showed no adverse effects on animal health, although metabolic profiles  confirmed the need to move ewes onto higher protein spring grass in the final three to four weeks pre-lambing. Focus areas identified in this study to support optimum lamb growth rates included maintaining  the quality of grass throughout the season and careful management of internal parasites.


Overall the project concluded that climatic conditions within the UK would be suitable for out wintering ewes on swedes, providing the crop is grown on suitable ground, as the nutritional value of the crop was maintained throughout the season, supporting ewe requirements in early to mid-pregnancy.

ADAS can give advice on the following:

  • Business gross margins and profitability projections
  • Long term business sustainability
  • Projected targets for outputs and margins
  • Sustainable, cost effective sheep systems
  • Practical aspects of out wintering ewes and planning grazing systems

Project Team

For more information please contact Karen Wheeler or call +44 (0)1432 821021.