THE EFFECT OF SHEARING PREGNANT EWES PRIOR TO A WINTER-LAMBING SEASONON EWE AND LAMB PERFORMANCE IN THE SOUTHERN CAPE

About half of the 505 winter-lambing SA Mutton Merino ewes were shorn at four or fewer weeks prior to lambing at the Outeniqua Experimental farm near George in July-August 1991 and 1992. The remaining ewes, wit h a 6 - 7-month fleece, were only crutched. The reproduction of all th ese ewes was monitored, while data from 666 progeny were used to inves tigate the effects of shearing on early lamb growth and lamb survival to weaning. During 1991, shearing prior to lambing improved (P less-th an-or-equal-to 0.05) lamb birth mass by 4.9% relative to progeny of th e unshorn control group. There was also a tendency (P almost-equal-to 0.08) for shearing to improve lamb survival (0.73 vs. 0.64). During 19 92, birth mass and lamb survival of progeny of shorn ewes did not diff er from that of progeny of unshorn ewes. Shearing ewes prior to lambin g improved (P less-than-or-equal-to 0.01) their lamb daily gain (to ei ght weeks) by 8%. The productivity of ewes (expressed as mass of lamb weaned/ewe joined) also improved (P less-than-or-equal-to 0.05) by 19% in shorn ewes. The latter result suggests that biological gains may b e derived from the shearing of winter-lambing ewes prior to lambing, a lthough effects on lamb birth mass and survival were inconclusive. Sin ce shearing prior to lambing appears to be a cost-effective method of improving the efficiency of winter-lambing ewe flocks, further studies are envisaged.