FOODS AND FEEDING. 87 



cient energy to enable work to be done without the muscles wasting ; 

 and to store up in the body a certain quantity of fat as a reserve to draw 

 on at need. The flesh-forming and fat-producing groups overlap to some Uses of 

 extent and too sharp a line cannot be drawn between them, but their fesh and 

 essential functions are : the former to build up and maintain the organs ^^^ groups 

 and muscles of the body so that they can carry out the process of digestion 

 and make use of its results — the latter to provide the heat and energy 

 required for the muscles and organs to work with. 



3. Bone-making elements. These are mineral elements usually Bone- 

 termed " salts," compounds of lime, soda and potash, and are particularly making 

 essential for young, growing animals. Such elements are found in the group, 

 blood and other tissues of the body as well as bone, and there is a very 

 intimate connection between their presence in the food and the quality of 

 stock produced. They are particularly abundant in grass and hay 

 produced on limestone soils. 



4. Fibrous and woody elements. These comparatively indigestible Fibrous 

 materials exist in varying proportions in all vegetable foods. Whilst their group, 

 actual digestion may not be carried out to a very great extent, they are 

 nevertheless found to be necessary as providing the bulk so essential to 



the rations of herbivorous animals. They also act as a mechanical aid 

 during digestion in helping to split up the other parts of the food so that 

 they may be readily absorbed by the body, as well as being to some 

 extent digested themselves. The proportion in which they exist may 

 vary from about 2 per cent, in maize to 40 per cent, in straw. 



5. Water forms a considerable portion of all foods, even those which Water, 

 are usually considered dry, the percentage varying from about 10 percent, propor- 

 or 12 per cent, in grain to 90 per cent, in roots. ^^°" 



A good food for a working animal should contain the above constituents Require- 

 in such proportions that the greatest possible percentage of nourishment ments of a 

 can be extracted from it, and a sufficient amount and bulk can be good food, 

 consumed to satisfy all requirements, namely : — maintain the body 

 temperature — appease the appetite — -and produce the required work, 

 without upsetting the digestion or occasioning loss of flesh. If no one 

 food will answer all these demands then the ration should be arranged so 

 that its several components will do so in the aggregate, and such foods 

 are usually described as " well-balanced." From a well-balanced ration 

 the animal can extract the largest possible amount of nutriment, though 

 from no food, however suitable, is it possible for the total quantity of its 

 goodness to be absorbed by digestion. 



A table of the percentages of the various constituents of a large number Per 

 of foods is appended, and, while no precise conclusions should be drawn centages 



