982 THE COMPLETE GRAZIER. BOOK x. 



ance of animal heat. Just as we can utilise some part of the heat of 

 burning coal to boil water and then, by means of the steam produced, 

 to generate mechanical force (as in the steam-engine), so the animal 

 body can use part of the heat generated by the oxidation of its food to 

 produce mechanical force, whence arises all animal movement. The 

 mechanical movements which take place in the involuntary act of 

 respiration, in the beating of the heart, in the circulation of the blood, 

 &c., are all derived from force generated by the utilisation or oxidation 

 of materials derived from food. So also are the voluntary acts of walk- 

 ing, traction, &c., which we call work. In order therefore to maintain 

 an animal at a given weight, we must supply it with sufficient food to 

 keep up its temperature and to generate the force necessary for any 

 work that it may have to perform. If our object is to fatten it to get 

 the greatest increase possible out of a given allowance of food we 

 endeavour to make the conditions such that as little of the food as 

 possible is required for mere maintenance. Thus we find that an ox 

 in a stall fattens faster than an ox in the pasture, because, as he does 

 not walk about, he spends less of his food in the production of 

 mechanical force. Furthermore, in the winter, an animal in a fairly 

 warm and well-sheltered stall fattens more economically than in a cold 

 and draughty shed, because he has to spend less of his food in pro- 

 ducing heat to make up for the increased radiation which goes on in 

 cold or draughty surroundings. 



Summarising what has been said in the foregoing paragraphs, an 

 animal must consume a minimum allowance of food per day in order 

 that he may keep warm and move that he may live and maintain his 

 weight. Any further digested food (except when it is spent in work, 

 as with the horse) goes to " fatten " the animal, and the rapidity of 

 fattening depends, apart from the natural aptitude for fattening of the 

 individual animal, upon the judgment of the feeder in selecting his 

 foods, balancing their proportions, and regulating the quantity. Since, 

 whether he fattens quickly or slowly, the daily quantity of maintenance 

 food remains the same, as a sort of fixed charge, it is obviously to the 

 interest of the farmer to decrease the length of the fattening period as 

 far as possible. If he can get an animal ready for the butcher, by 

 liberal feeding, thirty days earlier than by a less liberal or less judicious 

 diet, he saves the daily cost of maintaining the animal for thirty days. 

 This saving will generally speaking be far more than the extra expendi- 

 ture upon the more liberal or better-proportioned diet that results in 

 the earlier fattening. 



It is in this consideration that we see the great advantage of early 

 maturity, and of late years the attention of breeders has been largely 

 directed to the selection and propagation of stock having the aptitude 

 for growing and fattening rapidly ; in other words stock that will, 

 during their lives, consume less food for merely maintenance purposes. 

 The skill and experience of the farmer is exercised in the selection of 

 the best bred animals from this point of view, and in taking the fullest 

 advantage of their power to fatten rapidly under a good regimen. 



So far we have spoken of food in general terms. We have now to 



