Hi Andy. Do you know how old this 'older ewe' actually is? Does she have all her adult teeth? If so, is she broken mouthed ie has she started loosing her adult teeth? When you say her udder is 'extended', what do you really mean? Sometimes the supporting ligaments can start to give so when she is in milk the whole thing starts to look very precarious. If she has had mastitis in the past and it has affected both quarters (daft expression that for an animal with only two parts to the udder but I suppose it comes from cows), either it will have been treated in which case she may well be fine, or there will be signs of severe damage to the udder, in which case she will not - and she should not have been sold to you. What I'm getting at is that you don't need to get rid of an 'older' ewe just because she is past a certain age. We are lambing a ewe who will be 15 in April.
However, if she has only just been covered,and you are sure that her 'extended udder' is not because she is about to lamb from the previous tup exposure, or for any other reason you don't think she can survive lambing, then best to send her for slaughter now than later. No-one has mentioned the effect on slaughtermen of killing an in-lamb ewe - the guys at our abattoir have told us how distressing it is for them.
From the point of view of eating quality, an in lamb ewe, especially close to term, will have put her condition into the lambs so will be pretty scrawny - best to let her lamb and recover, then send her off once she has weaned her lambs. Older ewes are excellent for sausages and burgers - not all that much meat but full of flavour. Having said that we have several old biddies which will never go to the abattoir
