Risk of twin lamb disease in early-lambing flocks

Harbro advises issue tackled at mating or mid-pregnancy

The risk of twin lamb disease, or pregnancy toxaemia, in early-lambing flocks has been highlighted by animal feed firm Harbro.

The company warns that the 40% energy increase required by multiple lamb-bearing ewes brings with it an increase risk of twin lamb disease (TLD).

It adds that greater grass growth than normal in many areas means some ewes may be in better condition than expected which can create a scenario for increased TLD risk as fat ewes with a depressed appetite and fatty livers cannot cope with the mobilisation of body reserves.

Harbro states that late pregnancy is not the time to reduce body condition in ‘over-conditioned’ females. However thin ewes in late pregnancy can also lead to an increased risk of developing TLD.

It takes six weeks to raise body condition by one score, so the company advises that the problem should be addressed at mating and midpregnancy.

“TLD is prevented by good feeding management, adequate feeder space (not just adequate feed) and feeding ewes at the same time every day,” the advice states.

“Ewes are programmed, once receiving feed, to look for feeding within 15 minutes of the same time every day.

“They will produce excess saliva at this time which will buffer acid produced in the digestion of the feed.

“This is one of the most important management considerations in any ruminant.”

Sudden stresses such as adverse weather, irregular feeding and handling can also trigger twin lamb disease.

TLD is prevented by good feeding, adequate feeder space and feeding ewes at the same time every day.

Early signs of the disease developing include decreased activity at feeding and more time spent lying.

This can progress to listlessness, aimless walking, muscle twitching and grinding of the teeth.

The later stages include blindness, lack of glucose and an overwhelmed liver. In severe cases there is instability, and once a sheep is down it can lead to coma and death.

Harbro offers a comprehensive nutritional package for the whole flock, with the aim of maximising health, fertility and growth, while ensuring effective feed conversion and results.

Qualified staff are on hand in their network of country stores.