Avoiding Twin Lamb Disease
26 February 2020
It’s now time to put a plan in place for appropriate nutrition and management during late pregnancy to ensure a profitable mid-season lamb production.
In the final 6-7 weeks before lambing, approximately 75% of foetal growth occurs. This rapid period of growth increases the ewe's need for nutrients and more than often, her daily requirements can no longer be met by a forage based diet alone. Correctly managing ewes energy metabolism in this critical period can help to reduce the risk of complications for the ewe such as pregnancy toxemia (Twin lamb disease) and subsequent hypocalcaemia.
Twin Lamb disease
Twin lamb disease is an energy deficiency and can occur around lambing, when getting sufficient energy into ewes during the last few weeks before lambing can be a challenge. This is an increased problem if ewes are thin, too fat or carrying multiple lambs. Additional stressful events such as change in weather, diet changes, foot problems and housing can also play a role in the onset of the disease.
If the ewe’s feed intake is below energy requirements, this is referred to as negative energy balance. Where blood glucose levels drop and the ewes body fat is broken down for energy. This backfat travels to the liver to be processed into energy but if excessive amounts are mobilised, the liver struggles to cope. With a rapid and large load on the liver, the fat breakdown is not completed, increasing blood ketone levels. This is termed pregnancy toxaemia, ketosis, or twin lamb disease. Twin lamb disease can lead onto other conditions such as hypocalcaemia, reduced milk production, reduced lamb growth and increased lamb mortality.
Clinical signs of Twin lamb disease
Affected ewes can be easily identified, in the early stages of ketosis, a ewe will separate herself from the rest of the flock. In the later stages, they may shake, circle, twist their neck, lift their head high, teeth grind and have a dull appearance. Loss of appetite, apparent blindness and signs of inability to stand are also common signs. Ewes near lambing may be weak and experience lambing problems. If the condition is untreated, it may result in death.
Ewes suffering from twin lamb disease should be treated twice a day with a product containing propylene glycol (Glycerin), vitamins and trace elements that stimulate appetite and liver function, such as Ewe-Keto. In severe cases, your vet may need to administer an injection of glucose and corticosteroids into the vein. Identified ewes should be offered palatable feeds to promote appetite and fresh water.
Early prevention of twin lamb disease is key, it is important to identify ewes carrying multiple lambs to ensure they are provided with a diet that will meet their higher energy demands This is the reason it is important to identify ewes carrying twins and triplets through pregnancy scanning. The level of nutrition should be gradually increased over the last 6 weeks before lambing, a 70 kg ewe’s daily requirements increase from 8 MJ to 16 MJ in late pregnancy. Provide enough trough space and treat any lameness early to prevent this reducing ewe’s intakes. To provide the ewe energy, they can be given products containing gluconeogenic energy (generates glucose) from 2-3 weeks before and after lambing.