Depending on when the breeding season kicked off, some farmers will be lambing while some will be another three-to-four weeks away.
If it’s a case that you are a couple of weeks away from lambing still, it is important to feed ewes adequately to prevent against animal health problems – such as twin-lamb disease (pregnancy toxaemia).
Twin-lamb disease is associated with underfeeding ewes, which will have a serious knock-on effect on the ewe herself and her offspring.
During the final six weeks of gestation alone, 75% of the total foetal occurs. Therefore, failing to meet the ewes’ dietary needs for energy can result in cases of twin-lamb disease occurring.
It occurs predominately in the period right before lambing when the lambs are growing at their most rapid levels in the uterus. The stress associated with housing can also trigger the disease.
According to Teagasc, the response to treatment is usually poor and mortality can be as high as 90%. Therefore, prevention is critically important.
Symptoms
Ewes that are thin or who have a poor appetite and aren’t eating are most at risk of contracting twin-lamb disease, especially if they are carrying more than one lamb.
Pregnancy toxaemia occurs when a ewe’s energy requirements are not met; she begins to mobilise fat reserves. This leads to the production of ketones, which impair the ewe’s normal bodily functions.
A ewe suffering from twin-lamb disease will:
- Isolate herself from the rest of the flock;
- Look dull;
- Have no appetite;
- Appear blind and lie down for long periods.
If the condition is untreated, it results in death.
Prevention
To combat against this disease and ensure that ewes are in good health coming into lambing, it is important to carry out the following listed (below).
- Introduce concentrates six-to-eight weeks pre-lambing (depending on litter size) and increase the level of feeding gradually based on forage quality;
- House sheep three-to-four weeks in advance of lambing to avoid sudden dietary changes;
- Ensure ewes have adequate feeding space – especially when it comes to feeding concentrates;
- If you spot any thin ewes, then they should be given preferential treatment to bring them up to an ideal body condition score (BCS) of 3.0 at lambing time.
Treatment
The response to treatment is usually poor and mortality can be as high as 90%. However, ewes suffering from the disease will require glucose treatment as soon as they go off food.
This provides the best chance of survival for both the ewe and the lambs. The oral administration of glycerol or propylene glycol is also warranted.
The induction of labour may also be considered, as this immediately reduces the ewe’s energy requirement for foetal growth.