358 AGRICULTURAL ECONOMICS 



compared to an automobile whose engine must be kept running 

 at a low speed in order to have the power available when 

 needed. 



That the feed of the animal is its source of both repair material 

 and fuel is sufficiently obvious. If we knew exactly the requirements 

 of the animal in any given case, and if we knew exactly what amounts 

 of protein (repair material) and energy (the fuel material) the feeding 

 stuffs at our disposal could furnish, the computation of a ration would 

 be almost purely a matter of arithmetic. We should simply have to 

 devise a mixture of the feeding stuffs which would yield the requisite 

 amounts of protein and energy and would at the same time be of 

 suitable bulk and of such a character as to exert no injurious action 

 upon the animal. As a matter of fact, we have no such exact knowl- 

 edge. Practically, animals vary in their requirements, while feeding 

 stuffs of the same name show a wide range in composition, digesti- 

 bility, and nutritive value. Furthermore, what is still more impor- 

 tant, the economic conditions vary from case to case, so that, for 

 example, a very liberal ration might be advisable in one instance, 

 while for the same animal under different conditions it would be 

 highly uneconomic. A man's ability as a feeder will be shown, first, 

 in his power to estimate the conditions which will modify the feed 

 requirements of his particular animals and cause his feeds to vary 

 from the average, and, second, in the skill with which he can 

 interpret the daily results and modify his feeding in accordance 

 with them. 



When feeding stuffs must be purchased in order to get the desired 

 relation between the protein and the energy of the ration, it is evident 

 that often a wide range of choice may be offered. In such a case the 

 question at once arises, which of the various feeds available it is most 

 economical to purchase, it being evident, of course, that this is not 

 necessarily the one offered at the lowest price. In all. these and 

 similar matters common-sense is necessary. The computed ration 

 expresses the best estimate that can be made of the actual average 

 requirements, but it is at best more or less of an approximation. It 

 would be foolish, therefore, to seek extreme exactness in realizing it 

 or to go to more expense in the weighing and apportioning of the feed 

 than the saving in the latter would amount to. The scale upon which 

 the feeding is conducted will play an important part. Where scores 

 or hundreds of animals are being fed, an exactness may be profitably 

 sought which would be absurd in the case of two or three animals. 



