Influence of season and of reproductive status on the wool growth of Merino ewes in arid environment

Abstract

At Fowlers Gap, an arid saltbush environment in far western New South Wales, the wool growth of South Australian Merino ewes was measured at intervals of about ten weeks for three years. Highest rates of wool growth on dry ewes were recorded each year in late winter (1 0.8, 14.9, 15.7 g day-1) and lowest in late summer (6.0, 7.7, 10.7 g day-1). Changes in the rate of wool growth were associated with changes in pastoral conditions in two of the three years. Relative to dry ewes, the rate of wool growth of wet ewes was reduced by 9 to 24 per cent in late pregnancy, 21 to 43 per cent in early lactation and 3 to 26 per cent in late lactation. The reduction was inversely related to current pasture growth.