60 BRITISH DAIRYING. 



an increase of fat in the food bears no special relation to the pro- 

 portion of fat in the milk, though it will almost always increase 

 the yield; fat, indeed, is needed in the food to keep up the 

 heat of the cow's body, and will to a considerable extent be 

 used for this end ; but an increase of albuminoids in the food 

 finds a more ready response in the quantity and quality of the 

 milk. The component elements of the solids in milk are not 

 generally and materially affected by changes in the composi- 

 tion of the food, but to this rule some cows afford striking 

 exceptions. There is a natural limit to all cows' capacity for 

 yielding milk, and when a cow is fed up to this limit increased 

 or improved food cannot extend it. It follows, therefore, that 

 while a superior cow is seldom fed up to the limit, an inferior 

 cow may easily be fed beyond it. 



The practical inferences from these experimental data are 

 that the idiosyncrasies of each cow should be studied and 

 met, and that scientific feeding, while valuable as a guide 

 and as a study, is sometimes followed by results so dis- 

 parate and varying that no absolute rule can be laid down 

 to suit all cases. In the case of a boiler, the quantity of coal 

 and water required to produce a given volume of steam may 

 be calculated to a nicety ; but there is no such correspondence 

 applicable to cows generally between what a cow eats and 

 the milk she will yield or the flesh she will elaborate. The 

 feeding of cows, therefore, is an art, but not a science. So, 

 indeed, is agriculture in most of its bearings. 



The careful cow- keeper will see that his cattle are fed with 

 "just enough and none to spare." The art of economical 

 feeding, so far as quantity is concerned, lies in knowing how to 

 make the cattle eat all up cleanly and with a relish. Over-fed 

 cattle seldom thrive as well as those which have just what they 

 need and no more. A wise farmer I once knew said, " Better 

 keep your cows just a little 'on the snap ' than over-feed them." 



