Which physical trait is crucial to evaluate in sheep for wool quality?

The evaluation of crimp is essential for assessing wool quality in sheep. Crimp refers to the natural wave or curl in the wool fibers, which can significantly influence the wool's aesthetic properties and tactile feel. Wool with the right crimp can bounce back well, has a greater volume, and is more elastic, making it more desirable for various textile applications. High-quality wool typically exhibits consistent crimp, contributing to its strength and insulation properties.

Physical traits such as body weight, hoof size, and head shape, while important in overall sheep health and management, do not directly impact the wool's quality in the same way. Body weight may be relevant to growth and productivity, hoof size can affect mobility and health, and head shape may contribute to breed characteristics. However, none of these traits are indicative of the wool's fineness, texture, or overall quality, which is why crimp is the primary focus for evaluating wool quality in sheep.