Food Requirements of Animals. 



261 



genous foods for the purpose of increasing the value of the manure 

 produced, and in this way to maintain and increase the fertility 

 of the land. 



Before leaving this subject it may be valuable to call attention 

 to the relative efficiency of the different classes of farm animals 

 as transformers of food into body increase. Warington furnishes 

 some interesting data on this point : 



It will be seen that in proportion to its weight, the sheep eats 

 more food and yields more increase than the ox, while the pig 

 consumes more food and returns much more increase than either. 

 This is due to the concentrated and easily digestible character of 

 the food supplied the fattening pig. It must expend compara- 

 tively little energy in preparing the material for assimilation. 

 Again, the digestive apparatus of ruminants is anatomically dif- 

 ferent from that of the pig. In the former the capacity for the 

 storage of rough fodders is large, but the proportion of intestine, 

 where absorption is most active, is much smaller than in the pig. 



Requirements for wool production. Wool is the hair of sheep : 

 but the hair of certain goats, such as the alpaca, cashmere, and 

 mohair, as well as that of the camel, is also classed as wool. Wool 

 differs from ordinary hair only in its physical structure, being 

 covered with minute, overlapping scales, and having a twisted 

 or curled fiber. Wool has great affinity for water and may con- 

 tain from 8 to 12 per cent of moisture in hot, dry weather, and up 



