The influence of seasonal pasture production and grazing management on seasonal wool growth

Abstract

The wool growth by Merino ewes grazed on sown annual pastures and by Merino weaners grazed on sown perennial pastures was measured at six-weekly intervals for three years. The ewes were from four groups with different grazing treatments and the weaners were from two grazing treatments. Wool was clipped from tattooed mid-side areas and the weight of clean, oven-dry wool in each sample was determined and staple length and fibre diameter measured. In all pears and in all groups of sheep there were seasonal fluctuations in weight, length, and fibre diameter of the wool. Growth was rapid during autumn and late spring but retarded during winter and summer. With few exceptions the summer and winter minima were not significantly different. The exceptions were mainly due to the summer minimum for a group being less than the winter minimum for the same group ; only in two cases was the summer minimum significantly greater than the winter minimum, and in both of these there was drought during the autumn and winter. The results, obtained at Canberra, A.C.T., are considered representative of the southern and central tablelands of New South Wales.