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Country: Ireland

Dairy or/and meat sheep: Meat

Level of solution:






Just Being Tested

Aim:  To present the effects of optimum birth weight on productivity


  • Many factors affect lamb birth weight including litter size, gender, genotype and the nutritional management of the ewe during pregnancy.
  • Each 0.5 kg increase in lamb birth weight increases weaning weight (14 weeks of age) by 1.7 kg
  • The optimum birth weight:
  1. is the weight at which lamb mortality is minimised.
  2. for twins and triplets is 93% and 78% that of singles.
  • The effect of lamb birth weight on lamb mortality is shown in Figure 1.
  • Regardless of litter size, as lamb birth weight increases mortality decreases initially, plateaus and then increases again, reflecting the difficulties at lambing associated with large lambs.

Figure 1. Relationship between lamb birth weight and total mortality for lambs born as singles, twins and triplets

Expected benefits:

  • Achieving the optimum birth weight:
  1. reduces labour associated with increased lambing difficulty and very small lambs
  2. reduces lamb mortality
  3. improves flock productivity

Prerequisites and/or limits:

  • Requires good management protocols and nutrition planning during pregnancy.


Scientific basis:

Hanrahan and Keady (2013). Proc BSAS, p 275


Keady T.W.J. 2017. Nutrition of ewes during late pregnancy. Animal and Grassland Research and Innovation Centre, Teagasc, Athenry, Co Galway.


Tips and Tricks:

Ewe nutrition for optimum lamb birth weight
Producing high feed value silage
Lambing data


Level 1 assessment


Benefit expected mortality
less workload
better labor organisation
better feed management
less stress for the farmer 
Is the solution suitable for various production systems Y
If no – for which system  
What are the asset costs <100
What are the maintenance costs <50
Any limits to its applicability requires good management and nutrition plan during pregnancy
Work Load
  Farmers Service provider/tech.-vet-others
How much time is required to prepare and implement the solution <1 day  
How many people is needed to implement the solution? One  
How long it takes to get results? Immediate
How long it takes to see  an effect on sheep productivity? Current production period
  Farmers Service provider/technicians-vet-others
What kind of equipment/tool are necessary? NA  
Skill/Knowledge-Training (farmer)
Does the solution need any specific skill/knowledge or training? Knowledge of factory effecting birth weight
How much time will be required for training <1 day
Wider Environment
Is there any particular regulation link to the solution? no
Does the solution need any particular structure or organisation? no


Level 2 assessment

None available


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