[1] The production of such mule ewes is a widely used breeding management system which offers several advantages to the farmer.
Cross breeding the hill ewe with the lowland ram brings about hybrid vigour or heterosis, which brings the best characteristics of both breeds into one ewe that can be used in producing lamb for the table.
The hill ewe, for example the Scottish Blackface, is a hardy animal with good, natural mothering instincts.
This mule is usually crossed with a meat-type ram, such as the Suffolk or Texel, to produce these market lambs.
This breeding also allows a convenient system of management whereby hill ewes can be reared in difficult areas where other species would not survive to produce lamb.