Digestio n — Respiratio n — Calorimetry — Energy. 43 



fact that the content of the last part of the intestine of the ox re- 

 mains more watery and hence is subject to more complete fermenta- 

 tion. The more easily digested a feeding stuff is, the less differ- 

 ence will there be in its digestion by these various animals. For 

 the great majority of feeding stuffs the same digestion coefficients 

 may be used for the sheep and ox. 



The horse and pig digest less fiber than the ruminant, in whose 

 paunch the coarse feeds undergo special preparation and digestion. 

 The richer the feed the more nearly do the digestive powers of the 

 horse approach those of other farm animals. Swine digest the con- 

 centrates fully as well as do the ruminants, but make only small 

 use of the fiber. Age and breed do not affect digestion, tho indi- 

 viduals show considerable variations one from another. The spe- 

 cies, breed, or age of animals does not ordinarily cause variations 

 of more than 5 per ct. in digestibility. 



Neither the frequency of feeding, the time of watering, nor the 

 amount of water drank appears to influence digestibility. Within 

 reasonable limits the quantity of food the animal eats does not 

 affect its digestibility. Jordan^ found that sheep digested 4.7 per 

 ct. more of the dry matter when given a half ration than when fed 

 a full ration. Warington- states that an animal does not digest its 

 food any better during partial starvation, tho when an abundance 

 of rich food is fed its digestibility may be lowered. Healthy ani- 

 mals usually eat no more forage than they can properly digest, and 

 the digestive fluids are no more active on small than on large quan- 

 tities of food. Grandeau and Leclerc^ found that Paris cab horses 

 digested their rations best when given walking exercise or worked 

 at walking gait. AVhen trotting or at hard work their digestion 

 Avas lowered. Kindness should favorably influence digestion. On 

 the other hand, the flow of saliva and the other digestive juices is 

 checked by fright. Under skillful care animals show remarkable 

 relish for their food, and it is reasonable to conclude that better 

 digestion ensues, tho no confirmatory data can be given. 



The digestibility of a feed should not be confused with its avail- 

 ability. (69) 



II. Eespiration Studies. 



The respiration apparatus is an air-tight chamber, arranged in 

 such manner and with such devices that all that goes into and comes 

 from the body of an animal within it can be accurately measured 



»N. Y. (Geneva) Expt. Sta., Bui. 141. ' Ann. Sci. Agr., TI, 1884, p. 325. 



^ Chem. of the Farm, p. 150. 



