MANUAL OF CATTLE-FEEBmG. 229 



requires. If we conld eliminate tlie indigestible matters 

 entirely from the fodder of an animal, we should effect 

 the greatest posbible economy of work by the digestive 

 organs, and could produce an equal nutritive effect with 

 a correspondingly smaller amount of digestible nutrients, 

 since, as explained on p. 203, the production of work of 

 any kind implies a destruction of the constituents of the 

 body, which loss must finally be supplied by the food. 

 Such an extreme case is purely suppositious, but obviously, 

 the nearer we approach to it by the use of fodders contain- 

 ing a large proportion of digestible matter, the greater will 

 be the saving of work, although we have no accurate data 

 regarding the amount of the saving which could thus be 

 made. In Miller's system of exclusive meal-feeding, it is 

 probable that a portion, at least, of the saving in fodder 

 is due to the less amount of work imposed on the digestive 

 organs. 



In practice, however, considerations of profit come in to 

 modify the conclusions jubt drawn. 



As a general rule, a given number of pounds of digestible 

 matter can be had more cheaply in the form of coarse fod- 

 der, such as hay, straw, etc., than in the more concentrated 

 fodders, lilce the granis, which contains less indigestible mat- 

 ter. Moreover, ruminating animals are adapted by nature 

 to extract the nutritive matters from coarse fodder as com- 

 pletely as possible, so that it is obvious that under some 

 circumstances it may be more profitable to feed almost 

 exclusively coarse fodder (in wintering stock, for example), 

 while in other cases, e, ^., fattening, where a rapid produc- 

 tion is desired, the greater cost of concentrated fodders may 

 be more than covered by the economy of digestive labor 

 and the consequent saving of material which they cause. 



PiiODuortoK OF Heat. — The continual chemical changes 



