8 December 1995

Right ewe diet

lifts lamb crop

In the first of a two-part series, we examine how to feed ewes in late pregnancy to maximise this seasons lamb crop. Rebecca Austin reports

LATE-PREGNANCY feeding should aim to increase diet concentration to meet the demands of a rapidly growing foetus and udder development, advises Signet livestock consultant Peter Fairbank.

It is necessary to increase diet nutrient density and avoid over-feeding in mid-pregnancy because foetal development limits voluntary feed intake.

Mr Fairbank recommends ewes at condition score 3.5 at mating lose half a score up to lambing. For ewes in poor condition, such as under 2.5, he suggests increasing feeding levels by 20%.

"Have forage analysed and work out a feeding plan to optimise forage use, and do not delay concentrate feeding," he says. "Remember it takes the rumen 10 to 14 days to adapt to a change in feed."

He says that by scanning ewes it will be possible to feed and manage them depending on number of lambs carried. This does not necessarily save feed, but makes more effective use of feed and leaves even and viable lambs of a good birth weight – ideal for fostering.

He advises aiming for gradual changes in diet or formulation. "Ewes are fussy feeders and this will minimise the risk of putting the ewe off her feed," he says. Concentrates fed in excess of 0.45kg (1lb) a day should be offered as two feeds to reduce the risk of acidosis.

"Assess the condition of ewes and pen separately those that are not competing when feeding. Feed them to a higher level. Ideally, ewes should be penned in groups of no more than 40," he adds. He advises allowing 450mm (18in) of trough space for concentrate feeding.

"Take time to observe ewes at feeding. The one that hangs back is often a good indicator of the early onset of a problem.

"Use quality feeds, and always ask for an ingredient list when using compound feeds. Ewe concentrate feed costs are less than 10% of lamb output value in Signet-recorded lowland flocks. So dont penny pinch as non-viable lambs, or ewes with no milk, dont make lambs for sale."

Where fishmeal ideal

He stresses that protein with a good source of digestible undegradable protein is essential for colostrum and good milk production. "This is where fishmeal is ideal in late pregnancy because it produces quality milk and udder development.

"When feeding for lactation, maintain feed guidelines as at lambing, and reduce gradually with grass growth. Increasing the diets protein content is counter-productive as the ewe will burn energy to make use of that protein. She should be milking off her back immediately post-lambing. High rates of magnesium should be included in the diet at this stage to reduce the risk of staggers," he adds.

Finally it is vital sheep should have access to clean, fresh water at all times – especially when on a high concentrate diet and when the ambient temperature drops.

&#8226 Next week we focus on feeding straw-based diets to ewes in late pregnancy and visit a producer who is feeding straw due to low forage stocks.


&#8226 When winter feeding ewes on silage try not to get ewes over-fat in mid pregnancy for this causes late pregnancy intake problems and increases the risk of prolapses.

&#8226 Never feed poor quality silage. Soil contamination increases the risk of listeria.

&#8226 When feeding free access allow a minimum 15mm (6in) of space for each ewe. When restricted feeding allow 450mm (18in) a ewe.

&#8226 Feeding big bale silage reduces intake by 20% to 25% due to longer fibres.

&#8226 Feeding silage results in more urine than hay or straw. Clean bedding is vital at lambing.

&#8226 Feeding silage in individual pens is difficult. Many producers switch to hay which is putting another stress on the ewe as rumen bugs adapt to a different forage.

&#8226 Although very little concentrates are required with top quality silage, it is vital ewes still receive adequate vitamins and minerals.

&#8226 Producers with forage boxes can complete diet feed.

&#8226 Minerals should be sprinkled over silage daily. Fishmeal, at a rate of 60g/day, should also be offered in the last three weeks.

&#8226 It is often better to feed twins and triplets together and pen ewes separately.


Guidelines for hay-based diet*

Feed (kg) Weeks to lambing

6420

SingleHay1.31.21.00.8

Concentrate0.250.400.500.65

TwinHay1.01.00.800.50

Concentrate0.400.600.801.00

TripletHay1.00.70.50.5

Concentrate0.50.71.01.2

*Above ration based on average, well made hay. Concentrate: ME 12.5MJ/kg, crude protein 16%, changing to 18% three weeks pre-lambing


&#8226 Hay consumption depends on type and quality, but budget on 1kg a head through last six weeks of pregnancy.

&#8226 Can be fed in hay racks, but when stemmy allow ewes to select more nutritious leaf and discard stem to bedding by feeding in walk-through troughs.

&#8226 Allow 450mm (18in) trough space for hay and concentrate feeding.

&#8226 Diets with concentrates fed in &#8226 excess of 1kg a day are

&#8226 difficult to achieve. It is better &#8226 ewes are keen on their food, &#8226 rather than overfed.


Guidelines for silage-based diet*

Feed (kg) Weeks to lambing

6420

SingleSilage4.44.44.54.8

Concentrates0.150.25

TwinSilage5.04.84.43.8

Concentrates0.150.250.350.45

Triplet Silage5.04.84.33.0

Concentrates0.250.35 0.500.70

*Precision chop silage with good intake characteristics. Concentrate: ME 12.5MJ/kg, crude protein 16%, changing to 18% three weeks pre-lambing

At lambing many producers switch from silage to feeding hay in individual pens. This places the ewe under added stress, as rumen bugs need to adjust to a different forage.