The effect of previous and current nutrition on wool production in southern Victoria

Abstract

The effect of different planes of nutrition on the wool production of Corriedale wethers at pasture was studied between August 1959 and December 1960. The plane of nutrition was controlled by rate of stocking. The effect of previous nutritional treatment on wool production was slight. It affected wool weight and fibre length for 160 one month and fibre diameter for two months. The differences in current nutritional treatment were accompanied by large differences in wool production except during the spring months. On the highest plane of nutrition the wool production showed little seasonal variation, apart from an initial increase in production during the autumn. On the medium and low planes of nutrition wool growth declined substantially in autumn and winter and increased again in spring. The mean fibre diameter of the wool that was clipped frequently was greater than that of fleece wool obtained from the opposite midside at shearing. Further, in the groups on medium and low planes of nutrition estimates of fleece weight based on the combined weight of periodical clippings were greater than actual fleece weights. It is concluded that, in the dry Victorian summer, wool production is influenced by the plane of nutrition in the previous spring for a short period only, and that in autumn and winter it is dependant almost entirely on the feed immediately available.

Stocking intensity and pastoral production: III. Wool production, fleece characteristics, and the utilization of nutrients for maintenance and wool growth by Merino sheep grazed at different stocking rates

“…This was not associated with a ohange in the ratio of dust, grease and suint to wool and it is assumed that the dust was localized in the tip. The effects of stocking rate on wool characteristics have been examined by a number of workers including Sharkey, Davis & Kenney (1962), McManus, Arnold & Paynter (1964 and Sumner & Wickham (1969). Our observations were in general agreement with, these workers.…”

Seasonal variation in fibre diameter and length in wool of grazing Merino sheep with low or high staple strength

“…This indicates a greater complexity in the control of wool growth than explained in the previously reported liveweight regressions. Sharkey et al (1962) and Sharkey and Hedding (1964) showed that liveweight relationships with wool growth were influenced by liveweight or liveweight change in the proceeding time periods due to delays in wool growth responses to changing nutrition. Nagorcka (1977), in an analysis of experimental estimates of wool growth, indicated a 3.5-week lag between changes in feed intake and wool growth.…”