Break (or window) in wool

A temporary interference with the growth of the wool, causing a marked thinning or cessation of wool growth of all or a proportion of the fibre population, and producing distinct (often visible) weakness in one part of the staple. A window or clear break in the wool is an extreme form of low staple strength and may be caused by the same factors causing low staple strength, for example, sudden changes in pasture, lack of feed or water, sickness, lambing or faulty dipping.