Monitoring health and welfare when wintering at grass

Managing animals over winter at grass presents specific health and welfare challenges. See our tips on preventative management.  

Back to: Deferred grazing/all-grass wintering

Is management different over winter?

Monitoring stock when wintering at grass is essential as some animals may not cope as well as others and require housing or managing differently. Before wintering, assess BCS. Any thin animals should not be wintered outside. Young animals should be grazed separately to ensure allocation is correct and account for growth requirements.

Potential health issues:

  • Loss of body condition
  • Internal and external parasites
  • Enzootic abortion (as a result of high stocking densities)
  • Snow blindness (pink eye, infectious keratoconjunctivitis)

Preventative management:

  • Body condition score (BCS) regularly, every 3–4 weeks
  • Faecal egg counts (FEC) for parasite burdens
  • Biosecurity for incoming/new livestock
  • Use of sheltered fields during bad weather
  • Vaccinate for clostridial disease
  • Blood testing to determine energy and protein supply

Other potential health issues

During a wet winter, the high water content of the grass contributes to the water supply, and a small moveable water trough is adequate to meet requirements. However, during dry winter weather, this can increase significantly (four litres/ewe/day was recorded on one farm). Therefore, water supply must be increased. Keep the fields with piped water for late pregnancy to meet the high water demands during this period. When feeding concentrates and conserved forage, be aware of the lower water content and ensure the water supply reflects this.

Removing concentrates from the diet may also remove a source of trace elements. Discuss the issue with your vet, and if a deficiency is suspected, blood and forage sampling is recommended.

Blood testing as a management tool

Blood tests can test for:

  • Beta-hydroxybutyrate (BHB) – an indicator of insufficient energy intake
  • Urea – an indicator of short-term protein levels
  • Serum Albumin – an indicator of long-term protein levels.

Discuss any blood test results with the vet and make changes to the diets or groups as necessary. Blood testing can be done through the farm vets, or for BHB, new on-farm tests are available. The figures below have been supplied by the Moredun Institute:

  • BHB is a ketone produced by the liver when ewes are using their own body reserves (normally fat) to compensate for low carbohydrate intake
    • The higher the level, the more body reserves they are using. If this process is too fast, pregnancy toxaemia can happen
    • Normal level – less than 1.1 mmol/litre
  • Urea is a by-product of protein breakdown in the liver, so if the levels are low, it means that total protein in the diet is low
    • As it shows up short-term protein supply, it is very variable and will be influenced by when the last feed was
    • Normal level: 2–3 mmol/litre
  • Serum Albumin is a protein made by the liver
    • If its levels are low, it can indicate a low protein diet
    • Normal level during late pregnancy: 26–30 g/litre

Useful links

Learn more about body condition scoring

Find out more about managing ewes for Better Returns

Controlling worms in liver fluke in cattle for Better Returns

Using brassicas for Better Returns manual

If you would like to order a hard copy of any of the following publications please contact or call 0247 799 0069:

  • Managing ewes for Better Returns
  • Controlling worms and liver fluke in cattle for Better Returns
  • Using brassicas for Better Returns