Successful lambing was down to getting ewe nutrition right all year, according to veterinary surgeon Davina Hinde of Bainbridge Vets, Leyburn, speaking at an AHDB event at Leeming Bar.
Dr Hinde said most problems, such as prolapse, twin lamb disease, weak and dead lambs, mastitis and milk production, related to nutrition.
Therefore, year round monitoring of body condition scores and ensuring ewes were in the right condition at key times was crucial.
She said: “Body condition scoring can make a big difference, but you cannot judge by eye, so it is important to get into the habit of putting your hand on them. Overfat ewes can create as many problems as those in poor condition.”
While additional supplementation was likely to be required in the weeks running up to lambing, it was important to optimise the contribution from forage.
Dr Hinde said: “Rumen health is key. You need to feed the rumen microbes and they feed the sheep. Rumen pH should be 6-6.5 and a constant balanced diet will help keep this stable.
"Saliva has an important role, both to dilute food and ease swallowing, and also buffers the rumen to maintain the optimum pH. Free access to clean water at all times is also essential.
DR Hinde says: “The aim is to optimise forage intake and complement this with the minimal amount of supplement, but it has to be the correct type and quality of supplement. It must have a high energy content and the right quality and balance of protein.
“Forage analysis is key. You cannot work out a diet until you know the dry matter [DM] of your forage. Most feed companies will provide this service. For clamp silage, take about 20 samples in a W-shape across the face of the clamp. If using bales, sample at least three or four.”
When working out diets, it is important to estimate how much a ewe can eat based on body weight and stage of pregnancy to devise a diet to meet requirements.
However, this should be monitored against actual intakes.
Any deficit in energy and DM intakes not supplied by forage must be provided by supplementary feeds to meet the nutrient demands of the ewe, which will depend on her stage of production.
Dr Hinde said: “When choosing a concentrate, be aware of what you are buying. Feeding a high quality compound usually works out cheaper, as less is required and forage is used more efficiently by the ewe.”
A compound with 12.3MJ/kg DM is recommended or at least higher ME than the forage offered. If a poorer compound of 12MJ/kg DM is offered, more will be needed and less forage eaten.
Use the list of ingredients on the bag to assess compound quality. These will be in descending order.
Beware of compounds with more than 2 per cent of fillers, such as oat feed. Molasses content is usually at 3-5 per cent and minerals and vitamins at 0.25-0.5 per cent.
When formulating home mixes from cereals and straights, it is important to know the quality/nutrient value and cost of ingredients.
Minerals, vitamins and trace elements
MINERAL supplementation should take into account the history of the farm and any known possible deficiencies.
Check the balance of minerals in ewe diets for late pregnancy and lactation using information from forage analysis, straights and compound feeds.
Too little, too much or an imbalance of the major minerals can cause problems with hypoglycaemia or hypomagnesaemia.
TO MAINTAIN STABLE RUMEN FUNCTION
■ Avoid any sudden changes in food type, for example, introduction of concentrates, change of forage or feed quality
■ Maintain constant frequency and timing of feeding
■ Feed whole grain, rather than crushed or ground cereals, to slow fermentation in the rumen; this allows microbes more time to digest the starch
■ Minimise stress from handling or transportation to avoid fasting as it affects microbes
■ Maintain good health, with effective and timely treatment of lameness for example, as this can lead to periods of low feed intake or even fasting
■ Ensure all ewes have adequate access to feed to reduce the number of ewes overeating and others not having sufficient food