74 MANAGEMENT AND FEEDING OF SHEEP 



Strength of fiber in wool — Strength of fiber in wool 

 means the ability which it has throughout its entire 

 length to resist the force of distention. The true measure 

 of the strength of fiber is the strength of its weakest part. 

 It will not avail to have fiber strong through much of its 

 length when weak through any part of the same. It is 

 one of the most useful and important qualities in wool, as 

 on the strength of the fiber depends in a large measure 

 the value of wool for manufacturing uses. 



Among the important indications of strength of fiber 

 are, first, a bright glistening appearance in the wool; sec- 

 ond, an abundance of oil or yolk in the same ; and third, 

 uniformity in the size of the fiber. The glistening ap- 

 pearance is largely the outcome of an abundance of yolk 

 in the wool, but this lustrous appearance is also accentu- 

 ated by the reflection of scales that surround the fiber. 

 Its presence, however, is not an absolute guaranty of 

 strength throughout the entire length of the fiber, for 

 there may have been periods during the growth of the 

 fiber, when an abundance of yolk was not present, a con- 

 dition that would be adverse to strength of fiber at such 

 times. During any periods when yolk is not adequately 

 present, there is more or less wear in the fibers through 

 friction. Insufficient nutrition which causes an insuffi- 

 ciency of yolk also causes weak fiber through lack of food 

 supplied to the same. It lacks strength, therefore, from 

 lack of food and through excessive friction. Lack of uni- 

 formity in the size of the fiber may be so marked that in 

 some instances it is apparent to the eye unaided. In other 

 instances it can only be detected with a microscope. It is 

 of great importance in wool, as when weak beyond a cer- 

 tain degree, it breaks during certain of the processes of 

 manufacture. 



Since strength of fiber is the outcome of nourishment 

 and of lubrication, and since both are produced by food, 

 it becomes apparent that if the fiber is to be uniform in 

 size and strength, the food fed should be suitable and am- 



