To date, the mild winter has resulted in many ewes coming through the winter in better condition than ever, resulting in concerns about over fat ewes and how to avoid twin-lamb disease.

With many of the hill lambings still to start, there is nevertheless still time to address body condition of ewes, and adjust nutrition accordingly.

According to a report from Harbro, twin-lamb is effectively an acute energy (glucose) shortage brought on by the massive, rapid increase in energy demanded by multiple foetuses in the weeks immediately prior to lambing.

Thin ewes suffer simply by running out of energy reserves, but fat ewes effectively poison themselves by the rapid mobilisation of back fat at a rate far greater than their liver can cope with. The result is the generation of toxic ketones which further exacerbate the problem by dropping dry matter intake. The issue can spiral out of control rapidly with ewes going off their legs and a high mortality if not treated in time.

The key with fat ewes is to understand the huge energy reserve potentially available on her back, and planning how to utilise it most effectively. Quality protein is essential. Back fat is pure carbohydrate, and when broken down in the liver creates glucose; the fat ewe needs quality protein to balance this release of carbohydrate. And this also means that by balancing with high quality protein, the ewes do not need to be overfed. Instead, a reduced supply of quality feed is more effective than high volumes of low density feed for these ewes.

Relying on the fat ewe to survive on forage alone is a recipe for disaster. She needs access to a constant supply of both quality feed and forage to protect against sudden changes in weather which often precipitate a sudden release of fat, and the onset of twin-lamb. This is where feed blocks and molassed feed licks play such an important role. By providing a constantly available source of energy, proteins and trace elements, these free-access feeds allow the at-risk ewe to consume additional energy at the time of need.

So, if you are looking at ewes which are in too good condition, there is still time to help prevent twin lamb. Despite being fat, they should now be receiving low levels of high quality feed to get the rumen bugs acclimatised to the feed ingredients.

By providing high quality by-pass protein it is possible to make use of this fat safely and reduce body condition in the weeks prior to lambing. Providing b-vitamins, cobalt and UDP will all help liver function, and free access energy licks will help protect against sudden changes in weather. As always, it is best to consult with your vet and feed specialist to plan an effective programme for your farm.


Early turn out along with the flush of spring grass will also mean an increased staggers risk. Increases in the occurrences of the disease in spring are as a result of rapidly growing grasses which are low in magnesium. It is important to ensure the best possible magnesium supplement is made available, especially to animals at increased risk, eg. lactating or older cows.