Abstract

Production data were collected over 4 years from a flock of 600 mixed-age Romney, Coopworth and Perendale ewes. There were approximately equal numbers of each breed. Ewes within breeds and age groups were randomly allocated to be shorn either once-yearly in January, once-yearly in July or twice-yearly in January and July. All ewes were grazed as a single mob throughout the year, except over mating when they were divided into breed groups and joined with rams of their own breed. The twice-yearly shorn ewes gave birth to, and weaned, heavier lambs and grew more total clean wool than the 2-once-yearly shorn groups which were similar. Shearing treatment did not affect ewe live weight, aspects of lamb production other than birth weight and weaning weight or total greasy wool production. Incidence of casting was less than 1%. Net wool returns from the ewes shorn once-yearly in July exceeded that of the ewes shorn twice-yearly which exceeded that of the ewes shorn once-yearly in January.

BW, Hogg, LM Catcheside, GJK Mercer, AJ Pearson, and MG Ashby

Proceedings of the New Zealand Society of Animal Production, Volume 50, , 293-296, 1990