Winter feeding ewes

Posted by on Oct 14, 2010 in Featured Slider | Comments Off on Winter feeding ewes

Winter feeding ewes

Can we make a difference to the incidence of vaginal prolapse in ewes (‘bearings’) by altering the early pregnancy management of the ewe to maintain their body condition ie early pregnancy nutrition?

Since 2005 groups of farmers in the lower South Island have been looking in to the relationship between pregnancy management of ewes and the occurrence of bearings.


Over time this project has increasingly focussed on early pregnancy management of ewes and changing to a longer grazing rotation over winter.

Can we reduce the incidence of bearings on high performance sheep farms?

The project started in South Otago in 2005. There appeared to be two factors that reduced bearings:

  • maintaining ewes on an even plane of nutrition (by allocating the correct amounts of feed) from pre-tup to scanning
  • changing how the feed was allocated over this period i.e. shifting every 4 days rather than every 2 days

South Otago Monitor farm report on reducing the impact of ‘bearings’ in ewes

Winter Ewe Mangement workshops

As a result of the previous research it was apparent that there were wider benefits to farmers from this information than just reducing bearing incidence. Improved understanding of the relationship between winter ewe nutrition, feed management, productivity and profitability is critical to the sheep industry. Many farmers focus on ewe management before pregnancy and again around lambing but lose sight of the importance of the weeks in between.

Early Pregnancy Feeding Summary
  • Start planning early to balance the need for feed, before mating, and in the winter
  • Consider the need for maintaining BCS
  • Know the value of the feed compared to the need to use BCS as a buffer
  • Early pregnancy feeding sets the scene for both this seasons performance and lifetime performance of the lamb
  • Changing the pattern of feeding may help prevent metabolic problems

Putting a value on Body Condition Score

Body condition score is an energy reserve that we sometimes call on when feeding conditions are tight. We tend to add condition when there is plenty of feed and reduce it when feed is short. To add condition it takes about 6 kg of pasture DM per kg live weight gain. When we take it off, 1 kg of liveweight gives us the equivalent of about 2 kg pasture DM.

Body condition score is also related to productive outcomes. Ewes at condition score 3 will produce about twice as much colostrum than ewes at condition score 2. Therefore, in bad weather, lambs born to ewes in condition score 3 will have a higher survival rate than those born to ewes at condition score 2. Ewes with greater condition score at lambing will also produce more milk and therefore their lambs will grow faster to weaning. Measurements made on New Zealand sheep suggest that twin-bearing ewes with a BCS of 3 will wean approximately 5% more lambs that are 1-3 kg heavier at weaning than ewes in condition score 2. Our results suggest that 0.5 BCS difference at lambing led to lambs 1.8 kg lighter.

Watch Mark Zino, a North Canterbury farmer discuss the value of condition score

With these relative values we can calculate how much feed we need and how much it is worth to us, from monitoring body condition score

Influences on pregnancy nutrition. Dr David Stevens, AgResearch

Read the full report and presentations

Winter management of ewes; FiTT July2009

Early pregnancy feeding for sheep by Dr D Stevens

Pre-tup nutrition: rethinking strategic feeding of sheep by Dr D Stevens

Farmers have demonstrated the effectiveness of longer winter breaks

KEY MANAGEMENT protocols when planning 4 day shifting

There are some important criteria when planning a shift to 4 day breaks for ewes post tupping:

  • Know ewe liveweight to determine maintenance ration (average lwt and range of lwt)
  • Know the BCS (average and range)
  • Formal NOT informal feed planning is required
  • Pre tupping: Determine if there is enough feed for winter
  • Allocate to achieve the required intake on each 4 day block (allow for the residual grazing level as well)
  • If paddock size or the weather is an issue during winter then shift the sheep. Four days is not the critical break length, as 3 to 7 days may be better on hill country
  • We can still use some 1 day breaks if we need to clean some pastures up.


  • Target BCS 2.5 to 3
  • Objective is to maintain BCS from tupping to lambing
  • Target an even BCS profile (feed planning and allocation)
  • Monitor BCS and trends and make decisions on BCS and Liveweight early
  • Preferentially feed light ewes (i.e. the heaviest ewe is usually double the weight of the lightest ewe in a mob)
  • BCS more important than liveweight (apart from absolute weight for feed planning)
  • A ewe BCS 0.5 higher at lambing equates to 30g/day improved lwt gain in lambs to weaning

Start at the correct BCS pre tupping and maintain it

Review: Body Condition Score and Bearings July 2012

No More Bearings Year 2 results comparing 1 day and 4 day shifts

What the farmers have found from changing their winter system

Read the key outcomes from the farmers who have changed to a 4 day shift over winter on pasture

A feed budget is the same as the financial budget for the farm!

  1. Measure the size of the paddock
  2. Measure the grass
  3. Know the liveweight of the ewes (and the range)
  4. Know the size of the mob

Ewe feed requirement calculator

Scandrett Rural Ltd Feed Budget Spreadsheet

Feed-Budget-Spreadsheet (pdf)

Country-Wide article on the merits of shifting ewes less often in winter

Shifting ewes every 4 days in winter in Western Southland

Benefits of weighing ewes

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