176 THE FEEDING OF ANIMALS 



ble matter, used 1,213 gram-calories less energy than the 

 exclusive hay ration, carrying 4,125 grams of digestible 

 matter. The hay ration cost for consumption 4.7 Calories 

 per gram of digestible dry matter and the mixed ration 

 only 3.2 Calories. This increased use of energy can only 

 be explained by assuming that the cost of consuming the 

 grain was proportionately less than that of the hay, a 

 difference presumably due to the greater cost of masti- 

 cating the hay. 



The differences revealed by Kuntz's figures are inter- 

 esting and important. Chewing green food cost in labor 

 only about 18 per cent of the effort required to masti- 

 cate its equivalent of dry hay, the proportions of labor 

 for hay, oats, and corn being in the ratio of 100, 28 

 and 8J^. 



This author goes farther and calculates that the 

 work of mastication and digestion combined is 48 per 

 cent of the energy value of the digested material from hay 

 and 19.7 per cent of that from oats. He also makes the 

 statement that in general the coarse foods have 20 per 

 cent less net energy value than the grains. All these 

 deductions are based upon the excess of oxygen used by 

 the animal when engaged in the work of chewing and 

 digestion, over that used when at rest. It would follow 

 from these results that anything in the way of growth or 

 treatment of a fodder which tends to toughen or harden 

 the tissue reduces the net energy value. 



258. The work of digestion. Armsby regards the 

 work of digestion outside of mastication as a small factor. 

 His experiments when he attempted to measure the work 

 of mastication by the increased heat elimination, showed 

 no distinct evidence of such increase. He concludes that 

 there must have been an increased production of heat 



