Identify the ewes at risk and manage the energy balance correctly

Negative energy balance in ewes

During the last few weeks of sheep gestation, ewes are in negative energy balance. Correct feeding of ewes pre-lambing can be a challenge, particularly in ewes that are too fat and/or carrying twins or triplets. A change in weather, severe heat, cold or transport will result in a decrease in dry matter intake. Negative energy balance now leads to a drop in blood glucose which in turn will result in an increase in ketone production. This results in pregnancey ketosis, also referred to as pregnancy toxaemia or twin lamb disease in sheep.

Clinical signs of ketosis in sheep

At first, the ewe will separate herself from the rest of the flock. She will start shaking, circling, twisting her neck and lift her head up. Teeth grinding can be seen and heard. A sweet smell may be present on the breath. Ewes near lambing may be weak and experience lambing problems.

Reducing the risk of ketosis in sheep

To reduce the risk of ketosis in sheep, it is important to identify the animals carrying twins or triplets, separate them and provide them with a diet that will meet their increased energy demands. The level of nutrition should be increased gradually over the last 6 weeks of sheep gestation. Ensure there is enough trough space and avoid sudden changes of the ration; extra feed will be required in bad weather. To provide the ewe energy, it can be treated with products containing gluconeogenic energy from 2-3 weeks before lambing up to the first 2-3 weeks after lambing.

In animals carrying a single lamb, the risk is they become too fat. All animals should be maintained at a body condition score of 2.5-3.0 throughout gestation. This will avoid any ewe from becoming excessively fat.

Sheep with ketosis

Ewes with clinical signs of ketosis should be offered a product twice daily, containing propylene glycol as well as vitamins and trace elements stimulating liver function. In severe cases, an intravenous infusion with a glucose solution may be necessary.

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