Abstract

The effects of pre-lamb and conventional (post-weaning) annual shearing of ewes on their productivity and that of their lambs were studies over a three year period. Ewes (n-500) were selected from a flock of 5000 mixed-age Border Leicester x Romney ewes at Massey University's Riverside property in the Wairarapa in April 1989 and randomly allocated to two equal sized groups. Both groups were managed under the same conditions until December 1991. Throughout the trial, one group was shorn after weaning in November/December and the second group was shorn prior to lambing in August. Ewe liveweight and lambing performance were measured over three years, and individual ewe fleeceweights were recorded over two full years. Pre-lambing ewe liveweights were similar for both policies in all years, while post-weaning liveweights were greater in pre-lamb shorn ewes in 1989 only. Annual fleeceweights were significantly (P<0.05) greater for the pre-lamb shorn ewes in 1990 (4.07±0.05 vs 3.64±0.06 kg) but not in 1991 (3.61±0.08 vs 3.75±0.09 kg). Lamb birthweights and weaning weights did not differ between shearing treatments. The small difference in ewe and lamb performance between the shearing treatments suggests that management factors, such as the provision of feed and shelter post-shearing, the spread of seasonal work, net income per ewe and cashflow, should determine whether a pre-lamb shearing policy is adopted.

N, Dabiri, WJ Parker, ST Morris, and SN McCutcheon

Proceedings of the New Zealand Society of Animal Production, Volume 54, , 223-226, 1994