Previous work on winter shearing has concentrated on lowland ewes in mild conditions. With increased emphasis in hill areas on housing ewes before lambing and resting hill pastures, the possibility of shearing ewes before lambing, rather than in the summer now exists. A review of work with lowland ewes has shown that winter shorn ewes produce lambs with a heavier birthweight (average +0.55kg) and increased liveweight gain (average +15g day-1) (Phillips, 1980), but it is not clear whether these benefits would be obtained with less prolific ewes under hill conditions.

The experiment was carried out from February to July 1985. Twenty-two Welsh Mountain ewes were housed 45 days pre-lambing in a fully enclosed but well-ventilated shed with slatted flooring. At 42 days pre-lambing ewes were randomised for weight and age and half the ewes were shorn with a normal comb, and half left unshorn until the summer.

Ewes in both treatments were offered and consumed the same level of concentrates (0.25kg ewe-1 day-1 post-shearing increased to 0.5kg ewe-1 day-1 before lambing). Medium quality hay was offered ad-libitum to both treatments. Water intake was measured daily. Ewe liveweight was measured weekly on five occasions between shearing and one week before lambing. Respiration rates of ewes were measured on 4 different occasions at 4 extreme environmental temperatures. Maximum and minimum house temperatures were recorded for the whole of the housed period. Lamb birthweights, liveweight gains and 84 day weights were corrected to male singles using additive correction factors derived from the mean of the flock over the previous two years.