82 



FEEDS AND FEEDING, ABRIDGED 





III. Wool Production 



Composition of wool. — Aside from moisture and dirt, "wool" is 

 made up of pure wool fiber and yolk, the latter including the suint and 

 the wool fat. The wool fiber is practicallj^ pure protein, and is of the 

 same chemical composition as ordinary hair, but differs in being 

 covered with minute overlapping scales. The suint, 

 chiefly composed of compounds of potassium with 

 organic acids, comprises from 15 to over 50 per ct. 

 of the unwashed fleece, being especially high in the 

 Merino breed. As suint is soluble in water, most 

 of it is removed by washing the unshorn sheep or 

 the fleece, and less is present in the wool of sheep 

 exposed to the weather. The fat, often incorrectly 

 lalled yolk, is a complex mixture of fatty sub- 

 stances, insoluble in water, and may make up from 

 S to 30 per ct. of the weight of a washed fleece. 



Requirements for wool production. — Owing to 

 tlie large amount of j)rotein stored by sheep in their 

 tleeces, their rations should contain somewhat more 

 protein than rations for cattle or swine at the same 

 stage of maturity. This is taken into consideration 

 in the various feeding standards for the different 

 classes of animals. (See Appendix Tables IV and 

 V.) With ewes which are either pregnant or suck- 

 ling lambs, there is a double demand for food pro- 

 tein, which makes a liberal supply especially ad- 

 visable. 



When sheep are fed insufficient food to maintain 

 their weight, the yield of wool is considerably di- 

 minished. On the other hand, the production of 

 wool fiber and wool fat is practically no greater 

 when a full-grown sheep receives a liberal fatten- 

 ing ration than when it is maintained in ordinary condition. Feeding 

 lambs liberally produces a larger body and consequently a heavier 

 fleece. 



The strength of the wool fiber is dependent on the breed, the quality 

 of the individual sheep, and the conditions under which they are 

 raised. Conditions which check the growth of the wool, such as insuffi- 

 cient feed, undue exposure, or sickness, will produce a weak spot in 

 the fiber. The feed and care for the flock should therefore be liberal 

 and as uniform as possible. 



Fig. 25.— Wool 

 Fibers 



Appearance of 

 fibers, greatly mag- 

 nified, after dirt 

 and yolk have been 

 removed. Left, 

 fiber of jMerino 

 wool; right, fiber 

 of Down wool. 

 Note the overlap- 

 ping scales cover- 

 ing the fibers. 



