15 December 1995

Trying out a straw based diet on this seasons lambers

The second of our two-part series on feeding ewes in late pregnancy examines supplementing straw-based diets. Rebecca Austin reports

TRADITIONALLY hay is fed to both the early and spring-lambing flocks at Oxford University Farms. This is the first year that straw has formed the diets base.

Farm manager David Sharpe says that due to the summer drought the farm has made only 40t of hay- one third of its normal volume.

To satisfy the ewes nutritional requirements, Mr Sharpe is offering the diets produced in the tables to ensure ewe and lamb receive the correct levels of protein, energy, vitamins and minerals.

Ewes which scanned in October with twins and triplets for January lambing came in three weeks ago. A late flush of grass has allowed Mr Sharpe and the farms shepherd, Martyn Cameron, to leave out the single-bearing ewes and hence save on forage stocks.

On average the early flock scanned at 203%. It was synchronised and of the 283 ewes which went to the ram, 16 barreners went into the flock due to lamb in March and April. These will be scanned in January.

Ewes are shorn at housing. As Mr Sharpe is aiming for the Easter lamb market, the ewes stay in until weaning. "Shearing the ewes means they do better, lambs are bigger at birth and it allows us to get more into the shed," explains Mr Sharpe. Generally ewes will be in condition score 3 at lambing, dropping to 2 by weaning.

Early lambers receive no concentrates before they come inside. Then they are fed twice-a-day the diet drawn up by an independent consultant. To within a week of lambing the concentrate is a high energy 18.5% crude protein home mix – as shown in the table. This then moves up to a 20% crude protein mix to allow the ewe to lactate successfully.

Straw is available ad lib in racks as well as in the bedding. This allows them to pick through it and eat the leafy parts.

Mr Sharpe will change to feeding the ewes hay at lambing because he believes ewes milk better off hay and he has sufficient in stock for the early lambers. "But I have decided to stick with straw until lambing to prevent the ewes eating too much of the more palatable hay and so avoid the risk of prolapses," he says.

New bulk storage facilities have allowed Mr Sharpe to buy in straights for the first time. They also enable him to include rapeseed meal in the ration which reduces the feed bill. "I am very aware feed prices have increased again so I have tried to introduce rape and reduce use of fishmeal," he says.

Advantage of straights

"The great advantage of buying straights is that you can make whatever diet you like, whenever you like". This option comes into place at weaning. Four weeks post-lambing, fishmeal is removed from the early flocks diet in an attempt to stop weight loss from ewes and start drying ewes off. At five weeks, all protein sources are out. By weaning, seven weeks after lambing, all concentrates and hay have been removed and ewes are fed straw for two weeks before being turned out.

The spring lambing flock is fed similarly up to lambing, but will stay on the 18% protein concentrate. The 1kg of concentrate fed is maintained for a week post-lambing. "We always keep the ewes and lambs in for a week after lambing to ensure the lambs are strong enough because there are plenty of foxes about. After turn out, we only continue to feed triplets," says Mr Sharpe.


Guidelines for straw-based diet

Feed (kg) Weeks to lambing

6420

SingleStraw1.21.21.00.7

Concentrates0.450.520.700.93

Twin &Straw1.01.00.70.5

Triplets*Concentrates0.60.751.01.2

NB. Assume ewe able to select the more nutritous parts of straw. Vital for the success of this system. Diet assumes correct mineral balance for ewe on 18% protein, 12.5MJ ME concentrate.

*Every three weeks put sheep through 10% zinc sulphate foot bath. Use this opportunity to pull out thin ewes for access to hay, or more trough space, or access to supplementary feeds such as blocks, pails or licks.


Ration fed with ad lib straw to early lambing ewes up to one week before lambing and to spring lambers until turnout after lambing (18.5% crude protein, 12.9 MJ/Kg ME)

FeedInclusionCost(kg/t)(£)

Barley61071.37

Molassed sugar

beet pulp10011.20

Hipro soya9018.00

Rapeseed meal12515.63

High UDP fish2511.50

50% fat254.75

Vitamins255.38

Totals1000137.82


Ration fed to ewes & lambs from within one week of lambing with ad lib straw (19.8% crude protein, 12.9 MJ/Kg ME)

FeedInclusionCost(kg/t)(£)

Barley57567.28

Molassed sugar

beet pulp10011.20

Hipro soya12525.00

Rapeseed meal12515.63

High UDP fish2511.50

50% fat254.75

Vitamins255.38

Total1000140.73