The production of a heavier and better fleece per ewe is a matter of considerable concern to the sheep raiser, particularly on the western ranges and in other parts of the country such as the Ohio fine-wool region, where wool production is a specialty. Quality as well as quantity is, of course, important if a good price is to be obtained for the clip. However, it is entirely possible to have high quality of wool in fleeces that have good length of staple and heavy weight of clean wool. In fact the investigations of the Bureau of Animal Industry show that length of staple and weight of clean wool per fleece are associated with superior quality.

While many factors are involved in the improvement of wool, the most vital are those which tend toward greater production. These in the main are weight of the scoured fleece and length of the staple. The inheritance of the sheep (fig. 249), its feed, management, and seasonal environment are important factors that influence both quantity and quality of the wool produced, but the most fundamental of them all is the inherent tendency of the individual sheep. The utilization of this last-mentioned factor for greater wool production is, of course, the most difficult. Whereas proper feeding and management may be accomplished in the flock as a whole, and seasonal variations may to a limited extent be controlled by management, the improvement of a flock by means of the natural characteristics of the sheep themselves must be handled through the selection or culling of individuals. Successful sheep raisers have found that rigid culling of the aged ewes and light producers is a good practice for the immediate improvement of their flocks. They have found also that selective breeding is essential for future improvement.

FIGURE 249.— Yearling daughters of a famous Rambouillet ram, Prince of Parowan, showing uniformity in type and wool of good combing length. The sire of these ewes has a record of having produced 31½ pounds of wool a year during the first seven years of his life

Some Experimental Results

The fleeces of 100 Rambouillet ewes of the Government flock at the United States Sheep Experiment Station, Dubois, Idaho, which were grown in the years 1923, 1924, 1925, and 1926, were studied with respect to their yields of clean wool per fleece and the influence of their age and the season on these yields. Length of staple seemed but slightly affected by season. In 1923 it averaged 2.21 inches; in 1924, 2.14 inches; in 1925, 2.22 inches; and in 1926, 2.12 inches. There was a slight tendency for decrease in length with greater age.

A considerable difference in the average weights of clean wool was evident in each of these years. In 1923 the fleeces averaged 3.69 pounds of clean wool; in 1924, 4.05 pounds; in 1925, 4.20 pounds: and in 1926, 3.79 pounds. The variation can be attributed primarily to seasonal variation of feed, as the same ewes were considered throughout and otherwise their management was practically the same.

In spite of the above-mentioned irregular variation in the average yield of clean wool of these 100 ewes in the four different years—which must be attributed to seasonal effect—one influence remained stronger than that of season, the tendency of the ewes to produce light or heavy fleece weights, long or short staple, consistently. The ewes were divided, in 1923, into their four main fleece-length classes (averaging 1.3 inches, 1.8 inches, 2.3 inches, and 2.8 inches, respectively), and these classes were compared in the remaining three years. The results showed that, class for class, those ewes producing the shortest staple in 1923 continued to produce the shortest staple in the succeeding years, the next shortest class continued to produce the next shortest staple, and similarly for the other classes, so that, class for class, these ewes continued to produce staple of consistently comparative length in each succeeding year.

Similarly, when the ewes were divided into three main classes for clean weight of wool (averaging 2.5 pounds, 3.5 pounds, and 4.5 pounds, respectively, for 1923), the same condition existed. The classes producing lighter weights of clean wool in 1923 continued to produce lighter weights in the succeeding years, and those producing heavier weights continued to produce heavier weights in the succeeding years.

It is evident, therefore, that while season must be considered and every possible means used to offset adverse climatic conditions by proper feeding and management, if good wool yields are to be obtained, it is most important to select and maintain in the flock those ewes with heavier clean weight of fleece and greater length of staple, and to use rams which transmit these qualities.