52 Feeds and Feeding. 



oats only a little over 1 per ct., and corn but one-third of 1 per ct. 

 He estimates that with the horse the work of digestion calls for 

 about 9 per ct. of all the energy in the digestible portion of the 

 food. He further found that each 100 lbs. of fiber, or the woody 

 part of feeding stuffs, in passing thru the animal, whether digested 

 or not, required about 118 therms for the work of disposing of it. 



The digestive processes call for a large amount of work, and this 

 means an evolution of heat. Such roughages as straw, hay, and 

 corn stover, because of their coarse, woody character due to the 

 fiber they contain, place much work on the animal in digesting 

 them and passing the waste out of the body. Where the animal, 

 such as an idle horse in winter, is doing no work, living on coarse 

 food may bring no harm but rather economy in cost of keep, be- 

 cause the large amount of heat necessarily evolved in the diges- 

 tion and passage of such food helps to keep the animal warm. On 

 the other hand animals at hard work and those producing milk or 

 being fattened cannot profitably utilize large amounts of coarse 

 forage. 



The data of the table we have been studying are as a whole cor- 

 rect, interesting, and helpful in extending our knowledge of a diflfi- 

 cult, tho most important, subject of animal nutrition. In details 

 the data are more or less imperfect. It is hardly probable, for 

 example, that corn evolves as much methane gas during digestion 

 as does straw, and more than timothy hay. The student should not 

 regard the figures in each division of the table as exact and final, 

 but rather as approximate to the facts. Taken in the right spirit, 

 these data are of the highest value in setting forth what portions 

 of the food consumed by the animal are lost at each step in their 

 progress thru the body, and how a considerable part of the value 

 of the food is required to carry on the work of mastication, diges- 

 tion, and metabolism, leaving a relatively small portion ultimately 

 available for building the body or for external work. The marvel 

 is that the scientists have been able to go so far in solving these 

 most complicated problems, and that their zeal is still unabated. 



