The availability of high quality pasture for mating is frequently limited in hill farming systems. The majority of ewes usually conceive during their first oestrous cycle after ram joining. More effecient use might therefore be made of better grassland if ewes could be successfully returned to their hill grazings part way through the mating period. This would allow either a longer period of availability of improved grass before ram joining or more logically access by a larger number of ewes to the improved grassland area.