20 January 2020
Sheep farmers who carefully manage ewe nutrition in the last eight weeks of pregnancy will be rewarded with the successful growth and development of the unborn lamb.
Ewe nutrition is important at all stages of pregnancy, but farmers attending workshops on preventing lambing losses were told that the last eight to six weeks was especially crucial.
If nutrition is poor, newborn lambs will have inadequate levels of brown fat, leaving them cold and weak, said vet Miranda Timmerman, of ProStock Vets.
This brown fat is the only energy source for the newborn lamb and will keep it alive and vigorous for a few hours after birth, she told farmers attending one of the workshops at Nevern.
In normal conditions, this is enough time to allow the lamb to dry off and start to suckle the colostrum.
The lambing losses workshops are among a series being delivered across Wales by Welsh Government, Farming Connect, Lantra and NADIS in conjunction with veterinary practices.
Ms Timmerman advised farmers that monitoring the body condition score (BCS) of ewes regularly will ensure that they are not getting too thin, or indeed too fat, at any stage.
“A thin ewe will be more interested in what she wants to eat, not in feeding her lamb,’’ she said.
Lowland breeds such as the Texel should be at BCS 3.5 at lambing and upland breeds at 2.5-3.
It takes eight weeks on plentiful grazing to gain 1 BCS.
Pregnant ewes must be fed according to the number of foetuses they are carrying, therefore, scanning is important.
Ewes with singles, twins and triplets should be managed as separate groups and fed differing amounts.
Any deficiency in energy intake and dry matter intake (DMI) not supplied by forage must be provided by supplementary feeds.
Getting silage and hay analysed will inform the level of supplementation needed.
Sheep need the best quality feed before lambing. “Preserve silage properly as sheep are a lot more sensitive than cattle to poorer quality silage,’’ said Ms Timmerman.
Practical measures such as removing uneaten silage and replacing it with fresh forage will increase intakes.
Feeding a Total Mixed Ration (TMR) will also maximise intakes.
Giving ewes small amounts of concentrates regularly will prevent acidosis, advised Ms Timmerman. “Twice a day is quite common,’’ she said.
Monitor intakes to ensure they are eating what they have been given. Supply the correct levels of minerals also.
Farmers can monitor nutrition with a ketone meter – it is recommended that this sheep-side test is done 2-3 weeks before lambing as it allows the risk of twin lamb disease to be detected.
Elevated energy demands placed on pregnant ewes in late gestation mean sheep can lose condition and suffer from this disease.
As a result of the high demand for glucose, the ewe starts to rapidly break down her own body fat reserves and this produces toxic chemicals called ketones, which rapidly build up in the blood.
In order to prevent twin lamb disease, farmers need to accurately ration nutrition for ewes.
Nutritional factors can also lead to vaginal prolapses; if ewes that are too fat or have been fed a bulky, high forage diet in late pregnancy, they will be prone to this.
Providing ewes with appropriate nutrition can prevent prolapses, said Ms Timmerman.
Affected ewes must be clearly marked and culled as recurrence of the vaginal prolapse is common, she recommended.
Farming Connect, which is delivered by Menter a Busnes and Lantra, is funded by the European Agricultural Fund for Rural Development and Welsh Government.