Outwintering heifers

Published 24 January 14

‘If you don’t measure it, you can’t manage it’

‘If you don’t measure it, you can’t manage it’ that was the key message at the DairyCo outwintering event in Devon earlier this week. DairyCo’s Grassland, Forage and Soils Research Partnership with Harper Adams University has for the last three years been examining the performance and economics of outwintering systems for dairy heifers. On Tuesday (January 21) over 75 farmers attended the meeting to discuss outwintering options for replacement dairy heifers with Liam Sinclair and Norton Atkins, researchers from Harper Adams University and local dairy farmer Rob Uglow. DairyCo’s Kate Williams reports from the event.

Site selection

Outwintering reduces capital costs in housing over the winter months however in order for animal performance to be maintained in adverse weather conditions, appropriate site selection is crucial.  “Soils must be light and free draining” says Liam. “In extreme weather conditions, cows will lie down to conserve heat hence providing a dry lying or run back area and shelter, will reduce the animal’s energy needs and avoid cold stress’ he continued.

Site selection and forage allocation strategies are also crucial to minimising surface runoff and soil damage. High yielding crops such as fodder beet (which can produce up to 15 – 25 t DM/ha) require a high stocking rate for optimum utilisation, therefore free draining soils are needed to minimise poaching.

Devon farmer Rob Uglow has been outwintering his dry cows and heifers for 10 years and during this time he has experimented with various winter crops including kale and forage rape.  Currently outwintering 300 dry cows and heifers on fodder beet, he uses a block grazing system.  “With the high rainfall we have had recently, we have found that grazing in blocks on our fodder beet reduces the soil damage as animals do not pace the line of the fence that is found with strip grazing’ Rob explained.

Forage options

A recent survey undertaken by DairyCo and HAU has shown that deferred grazing is the most popular outwintering forage for replacement heifers in GB (see Figure 1) with many farms choosing to use a combination of grass and forage crops such as kale and fodder beet. (see Figure 1)

Figure 1: A recent DairyCo survey shows that grass is the most commonly used forage for outwintering replacement dairy heifers.

Forages for outwintering 

Norton Atkins from HAU, also highlighted to farmers the importance of knowing the quality and quantity of the forage. “Measuring the crop available is vital to ensure cows are allocated the correct amount of feed to utilise the crop, avoiding wastage” states Norton.  “Grazing in the winter often utilises a different feed type to grass in the growing season. With lower dry matter contents available, platemeter results can overestimate covers, therefore, carrying out your own dry matter analysis will help to accurately allocate grass and target supplementation accordingly.”

“Likewise, measuring forage crops is essential for crop allocation” stressed Norton. “Simply by harvesting the forage from a defined area (typically 1m2) and weighing this with a bucket and a spring balance can give an estimate of forage yields” (see Figure 2). Dry matters can vary significantly with fodder beet (14 – 20%) and consequently lab analysis of the crop can be useful. 

Figure 2: Measuring the amount of fodder beet in a small area (usually 1m2) with a spring balance can give a good estimate of crop yield and help with allocating forages.

Outwintering 1

Fodder beet is very high in sugars so to avoid acidosis problems, at least one third of DM in the diet should be supplementary fibre with straw or big bale silage. Rob explained that placing bales in the field as they are made in the summer reduces travelling over the ground when conditions are wet. (See Figure 3)

Figure 3: Setting out bales during the summer months will minimise soil damage

Outwintering 2

Although there can be large variation in the yield and quality of crops, Liam highlighted that each of these crops can support sufficient growth and that regular weighing of animals was more important than the choice of crop itself. Monitoring liveweight gains (LWG) on 9 commercial farms last year, Liam has seen a range of LWG (-0.2 to +0.57 kg/hd/day) over the wintering season (Figure 4) in part due to the extreme weather. “However, it was very apparent” says Liam “that those farms in the study who were weighing animals on a regular basis were achieving the highest LWG’s.” (See Figure 4)

Figure 4: On-farm monitoring suggests that target liveweight gains can be achieved on any forage type, however frequent weighing of animals is key to achieving this.

Outwintering graph 2


Contingency Plans

Monitoring the group through regular weighing can identify underperformers. Prompt changes through supplementary feeding or housing can ensure growth and condition are not compromised. It is vital to have contingency plans in place for adverse weather conditions and underperforming animals. From a recent DairyCo survey, Liam highlighted that once underperforming animals are identified many farmers opted to either house or outwinter these in a separate group to help achieve target LWG.

The recent wet weather has highlighted the importance forward planning. During these times Rob checks animals twice daily and where necessary offers extra energy through additional big bale silage or allocating an additional area of fodder beet in the evening.


Outwintering is not necessarily a low labour alternative to housing with fences needing to be moved sometimes twice daily and frequent forage supplementation. Rob highlighted that although savings are made in capital costs of shed space, variable costs in the crop husbandry should not be avoided. “Spending more on protection and establishment of winter crops is advisable and will give you returns in yield” states Rob.

For more information on DairyCo research on outwintering click here: /research-development/production-systems/current-projects/out-wintering-systems-for-replacement-heifers/


Outwintering top tips:

  • Site selection is key to successful outwintering.
  • Measuring forage quantity and quality is important to maximise utilisation and reduce wastage of the crop.
  • Target LWG’s can be achieved on all forage types however frequent monitoring is key to realising these targets.
  • Forward planning is necessary to help mitigate the effects of adverse weather conditions.