29 December 1995

So, do you know your

ewes condition score?

By Rebecca Austin

IF YOUR flock is due to lamb in March, ADAS sheep consultant Lesley Stubbings has a question for you. Do you know your ewes condition score?

It is especially important this year, she says, because a soft autumn produced plenty of grass, and that means ewes have piled on condition. "Ideally they should score 3 to 3.5," she says. "But most ewes are likely to be in better condition than you think."

Reasonably firm pressure should be used to assess condition. When handling over the loin, the vertebrae will have a fair covering of flesh and fat at condition score 3.5.

Keep fat under control

Ms Stubbings urges flock masters try to control things so that ewes do not get too fat now. "If they do, you are stuck with it at lambing."

She says it is preferable that they lose condition, probably about 4% body weight, in the middle two months of pregnancy.

"When a ewe is over-fat, it inhibits maximum placental growth," she says, adding that it is not until eight weeks before they are born that lambs start to draw on the ewes reserves.

She suggests producers keep ewes on a maintenance ration until then. This should provide 8MJ to 9MJ of metabolisable energy and about 60g of digestible crude protein a day.

"Ewes should be able to get that from grass at the moment, as long as there isnt a frost or snow cover," says Ms Stubbings.

"Many producers, quite rightly, supplemented ewes during the summer and continued during tupping and early pregnancy. But dont keep up those high levels just for the sake of it. It costs money and pushes ewes too hard."

Straw-based diets

But with many flocks getting straw-based diets for the first time this year due to low forage stocks, Ms Stubbings warns against leaving ewes out too long, even though there seems to be plenty of grass available.

"Changing a ewes ration from grass to straw results in a change in rumen flora," she explains. "She will need a few days to adjust and effectively will receive little nutrition over that period."

To overcome any potential metabolic problems, such as twin-lamb disease, Ms Stubbings advises producers to offer straw and a small amount of 18% protein concentrate a week to 10 days before housing – which should be eight weeks prior to lambing. &#42