Seasonal Variations In Wool Production

Press, Volume XCVIII, Issue 29070, 5 December 1959, Page 8

Seasonal Variations In Wool Production

4 FEATURE of wool growth that was particularly important in New Zealand was the differences in month to month production within the year, Dr. A. E. Henderson. head of the wool department at Canterbury Agricultural College, told the New Zealand Grassland Association’s annual conference in Gisborne this week.

“The pattern is a fundamental one and even though its magnitude may be altered by feeding, its basic nature is evident under all circumstances.” he said in a paper on the relationship of feed and the quantity and kind of woo l produced. “Under a system of stock management where an attempt is made to have breeding sheep at a similar weight throughout the year, rate of wool production in January or February will be about three times that in June, the month of lowest production. This difference is apparently associated chiefly with the effects that changing day-lengths have on the physiological activity of the sheep and practical means of altering this are difficult to envisage. However this maximum-mini-mum ratio, is . vitally important so far as grade of wool is concerned. It is the direct and underlying cause of ‘break,’ to the extent that this fault can be i easily seen in a great proportion j of our wool. i “The importance of feed I supplies at the right time as a means of reducing the worst effects of seasonal production cannot be overstressed. “If sheep are held at constant weight in summer and autumn (and are fed very well in winter jthen the wool growth ratio may *be reduced to 2 to 1 and obvious

effects of break may not appear. The principle of good winter feeding is well appreciated. However to produce the maximum modification of the basic seasonal differences this feeding must begin early because near-minimum rates may be reached in May. Further, it must not be relaxed because wool growth reacts very quickly to alterations in feed supply and any effect produced is permanently recorded in the staple. In general the assessment of any wool is governed by the part of the staple which grows most vigorously—almost invariably the tip portion—and if even growth is the aim there must be a corresponding restriction of food in the periods of maximum growth.” Modification However, Dr. Henderson added “while this pattern of wool growth is clearly defined any approach to modification must be a common-sense one. For example feed supplies are usually ample in late summer and autumn; the ewe has no other demands at this time and wool growth can be stimulated most easily in this period There must therefore be some reluctance to forego these wool growing advantages, except that excessive fattening in this period should be avoided for other reasons. On the other hand, stimulation of wool growth is most difficult in the May-June-Jul y period and there might be equaT reluctance to have little returns in terms of wool for good feeding in this period. "In all this, with our dual-pur-pose sheep, many other things

need to be considered and the principles just discussed should not necessarily over-ride these considerations.”