A recent article in the Veterinary press (Crilly et al. 2021) reviewed our current thinking of twin lamb disease in ewes – a major clinical syndrome at lambing time.
Twin lamb disease is caused by a ewe being in negative energy balance (i.e. she requires more energy from her diet than she is obtaining) and applies to all flock types. This triggers a cascade leading to those familiar clinical signs – a down, depressed ewe, in some instances abortion, dead lambs or indeed dead ewes.
Those ewes most at risk of twin lamb disease include:
- Those ewes carrying multiple lambs who are in the last 6 weeks of pregnancy
- Those who are under OR over condition
- A diet not meeting the needs of the ewes
- Those with other disease process alongside such as Johnes disease, liver fluke, sheep scab, lameness
Ewes less than body condition score 2.5 at lambing have a 19.7% more likely chance of getting twin lamb disease.
The impacts of insufficient energy and twin lamb disease can include:
- Mortality in those ewes affected (up to 80% of clinical cases)
- Increased lamb mortality with just 12% of those lambs born from twin lamb disease lambs being born alive
- They have a higher rate of difficult lambings (50% needing assistance)
- An increased risk of mastitis
- Implications for ongoing milk yield
The costs for both our ewes and the bottom line are mounting. So how do we avoid this?
- Check what we are feeding our ewes – this starts with forage analysis where applicable or ensuring sufficient grass provision – twins and triplets may need additional input
- Reviewing how we are feeding our ewes – is there enough space, enough fresh forage, gradual changes in diet as we move to housing or increasing concentrates
- Identifying high risk ewes especially thin ewes and supporting them as soon as possible.
- Minimising ongoing other diseases – such as lameness, scab and fluke
How we can help minimise the risk of twin lamb disease:
- Submit forage samples as soon as possible to our laboratory for analysis and dietary review by a member of #TeamSheep
- Consider a pre-lambing visit when your ewes are settled on this diet – ideally 3 weeks pre-lambing – using our pre-lambing check and running pre-lambing bloods, we can assess and amend as needed
- Assess the risk of other diseases such as fluke
Flock Health Advisory Package members should remember they can use one of their visits for “Pre-lambing visits” as can our “Large Flock Package” members.
Emily Gascoigne – Synergy Farm Health, Veterinary Surgeon MA VetMB DipECSRHM MRCVS
RCVS Recognised Specialist in Sheep Health and Production
