Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Animal, Dairy, and Veterinary Sciences

Committee Chair(s)

Milton A. Madsen


Milton A. Madsen


James A. Bennett


David O. Williamson


Bliss Crandall



Wool is still the most valuable and the most versatile fiber used by man. Many questions regarding its production have gone unanswered for centuries. This problem is undertaken in the hope of contributing information which might be used in further study on the problem of wool density.

It is recognized that wool density is one of the four major factors affecting the total clean wool production of a sheep. If length of staple, diameter of fiber, and total surface area remain constant, an increase in density brings about a corresponding increase in total production of clean wool.

Wool fibers are produced by glands, called fiber follicles, beneath the surface of the skin. Density is controlled by the number of these follicles functioning within a given area.

Before great improvement in density can be made, it is necessary to know the mode of inheritance, it is necessary to know the density of each individual involved. Counting the fibere from any sizeable area is not practicable. Therefore, a technique is necessary for sampling the sheep and estimating the density on the basis of sampling figures.


The Wira Fleece Caliper is probably the most popular instrument used in sampling for density.

To determine the most effective method of using the Wira Caliper, different-sized samples are taken from a given area. Both sides of each sheep are tested, and sheep from different breeds are sampled. Density on all samples is determined by a standard laboratory procedure. The results are statistically analyzed to determine the variation in density as obtained by the different sample sizes.

In addition to the main objective, the variation in density between breeds, between sheep of the same brood, and the variation in density between sides on the same sheep is determined.