Diet is an important part of a successful lambing season
ACCORDING to Georgina Chapman from molasses blends specialists ED&F Man, problems in late pregnancy can not only reduce the total number of lambs born, but also compromise lamb viability and increase the number of lambs that need to be hand reared, all of which will reduce the total value of the lamb crop.
Georgina says the economic cost of imprecise late pregnancy feeding can be significant, adding that the loss of ewes and lambs is the visible consequence, but reduced milk yield and quality will affect lamb vigour and growth, possibly increasing mortality.
There could also be an increase in the number of lambs that have to be hand reared. The latest estimate is that these will cost £55/lamb to rear, to which must be added to the extra workload and disruption to the lambing period. Georgina says: “It will be important to assess both the ewes and the diet heading into the crucial six weeks before lambing to minimise the risk of twin lamb disease.”
This metabolic disease arising from the high nutritional demands of ewes in the last two months of pregnancy, when 70 per cent of all lamb growth takes place. Most cases develop one to three weeks before parturition, but it can be seen as early as six weeks before lambing.
Georgina says the rule that prevention is better than the cure is particularly true in this situation. By feeding the ewe effectively, in terms of both quantity and quality, and managing body condition, twin lamb disease can be prevented.
Ewes should not enter the last six week of gestation with a BCS of less than 2.5. This can be prevented by good feeding management, such as managing groups based on BCS and the number of lambs scanned.
However, Georgina emphasises that it is important not to try and reduce the BCS in over-conditioned ewes in late gestation. Instead, these ewes must be monitored closely for signs of twin lamb disease.
“Ewe requirements for energy and protein increase significantly in the last seven weeks of gestation to meet the demands of the ewe and lambs and prepare for lactation. “For a 70kg ewe carrying twins, the demand for energy and protein increases by 60 per cent between seven and one-week pre-lambing, rising from 11MJ/day to 18MJ/day. At the same time dry matter intakes are reduced as the rumen in constricted by the uterus.
Georgina adds: “Diets need to be carefully formulated to meet the requirements of the ewe and are the foundation of a successful lambing period. “Feeding an ED&F Man molasses-based liquid feed can significantly reduce the incidence of twin lamb disease. “Blends such as Sheepmol and Sheepmol Plus are high dry matter, high sugar blends of cane molasses, glycerine and liquid co-products formulated specifically to feed sheep. The unique mix of energy sources is ideal to promote healthy lamb growth and maintain ewe health.”
She saysthat while there may be plenty of over-wintered grass available, it will be poor quality, taking up rumen space while not supplying sufficient nutrients. The same will be
true for poor quality silages.
Georgina advises having silages analysed and retaining the best forage for late pregnancy and twin of triplet bearing ewes. For a 70kg twin-bearing ewe three-weeks pre-lambing, maximum feed intakes will be around two per cent bodyweight, so 1.4kg DM/day and she will require 15MJ/day of energy. An average silage cut with 10.5ME and an estimated intake of around 1.1kgDM/ day will provide 11.5MJ of energy, leaving a shortfall of 3.5MJ.
“This shortfall must be made up within the 0.3kgDMI remaining. A molasses-based liquid feed is a good option in late pregnancy as their unique liquid nature ensures minimal rumen space is required to lift the energy density of the diet. For example, a 13.5ME liquid feed fed at 0.3kg/day can provide 4MJ of energy towards meeting the ewe’s equirements,” she says.
Molasses-based liquid feeds are a palatable, practical and cost-effective supplement. Blends specifically formulated for ewes are high dry matter, high sugar blends of cane
molasses, glycerine and liquid co-products formulated to provide the necessary balance of energy and protein. There is also the option to include vitamins and minerals to ensure a balanced diet.
ED&F Man’s molasses blends can be fed either by top dressing forage, as part of a mixed ration/home mix or via a wheel lick feeder. The company also offers a range of lick feeders and can provide advice on the most suitable liquid feed for your farm.
“Trial work has demonstrated that feeding a cane molasses blend can improve fibre digestion, which is critical for pregnant ewes as it allows them to get more nutritional value from every mouthful of forage consumed. ED&F Man offer a range of molasses blends for sheep which also contain glycerine, a gluconeogenic energy source meaning it stimulates glucose production which is vital to support milk production.”
