I presume these are males? Male Ayrshire calves fetch £5 or less at the auction for a reason. They will eventually finish and provide tasty beef, but very little of it compared to all beef and most other dairy breeds.
My neighbour is a dairy farmer with an Ayrshire herd, and does rear his decent purebred bullocks for beef, mainly for themselves and their customers (farm shop and restaurant.) He castrates them with a burdizzo at a couple of months old, and hasn't ever said anything to suggest that they're difficult to manage.