PRODUCTIVITY AND COLD RESISTANCE IN EWES PRE-LAMB SHORN BY STANDARD OR COVER COMB

The cover comb has been developed in New Zealand as a means of increas ing residual fleece depth after shearing and so increasing the resista nce of shorn sheep to cold-stress. The effects of pre-lamb shearing ew es with cover or standard comb, and of leaving ewes unshorn until afte r weaning, on their feed intake, productivity, and cold resistance wer e studied. Border Leicester x Romney ewes were divided into three grou ps balanced for pregnancy status, ewe age and liveweight. Two groups o f ewes were shorn, by either cover comb or standard comb, on day 114 o f pregnancy (P114) and one group left unshorn until weaning on day 84 of lactation (L84). Ewes were managed under the same conditions during pregnancy and lactation. Ewes shorn pre-lamb by cover comb had lower mortality from shearing to lambing, and lower organic matter intakes a nd biting rates at P123-126 than ewes shorn by standard comb. These pa rameters did not differ between ewes shorn pre-lamb by cover comb and unshorn elves except biting rate which was greater in the cover comb-s horn group. Twenty days after shearing (P134), the liveweights of ewes were greater in the unshorn group than in the cover comb-shorn group (P < 0.05), which was in turn heavier (P < 0.05) than ewes shorn by st andard comb. Midside clean wool growth rates were greater in standard comb- and cover comb-shorn eu es during the post-shearing period (to d ay 40 of lactation) than in unshorn ewes (P < 0.05). Similarly, the yi eld and brightness of wool were superior (P < 0.05) in pre-lamb shorn groups. Lamb liveweights at birth, docking and weaning, and lamb survi val, were similar between shearing policies. Rectal temperature (RT) t vas significantly (P < 0.05) lower in both pre-lamb shorn groups than in the unshorn group on day 3 post-shearing (S3): but by S5 only the e wes shorn by standard comb had lower RT. These results suggest that th e greater amount of residual wool in cover comb- vs standard comb-shor n ewes provides a low cost practical method for reducing the two impor tant disadvantages of pre-lamb shearing, namely increased cold-stress and feed intakes post-shearing.