772 THE FARMERS' HANDBOOK. 



We have already seen that both succulence and bulk of food are factors* 

 of the first importance in the making up of rations; it is, therefore, necessary, 

 in order to complete the list, to add the classes of bulky food characterised 

 by succulence and by the amount of indigestible matter. 



Class V, Succulent Foods. — The most watery of the ordinary farm foods 

 is the turnip, which contains over 92 per cent, of water; the swede, mangel, 

 carrot, and similar roots follow next, with cabbage and the green tops of 

 roots and vegetables, their water content ranging from 89 to 85 per cent. 

 Clover (growing) contains about 83 per cent., and pasture-grass and potatofs- 

 about 75. Green fodder — that is. cereal crops cut for green feed — vary 

 from 70 to 79 per cent, water. Of these foods, several of the roots may be- 

 characterised as sugar-crops, notably turnip, swede, mangel, and beet, whereas, 

 the potato contains 16 per cent, or so of starch. 



Class VI, Foods rich in Fibre. — The cereal straws and hay, both of clover 

 and pasture-grass, are included in this class; the straws containing from 

 68 to 75 per cent, indigestible fibre, clover and meadow hay, on the other 

 hand, 25 to 26 per cent. 



The Proportions Digested. 



All the above figures require to be considered in the light of the different 

 digestibility of the various ingredients. This varies, as we have seen, not 

 only in the different kinds of food, but with different animals. Thus 

 ruminants are able to digest 81 per cent, of the nitrogenous matter in lucerne 

 hay, as against 73 per cent, digested by horses; 72 per cent, of the carbo- 

 hydrates in lucerne hay and 45 per cent, of the fat are digestible by 

 ruminants, whereas horses digest only 70 per cent, of the carbohydrates and 

 not more than 14 per cent, of the fat. Pigs, again, are able to utilise 84 per 

 cent, of the protein and 98 per cent, of the starch in potatoes, whereas- 

 ruminants can only assimilate 45 and 90i per cent, -respectively of these 

 ingredients. Ruminants, again, can always digest a larger proportion of the 

 fibrous material than can horses or pigs. They digest, for example, about 

 one-half of the fibre in wheaten straw, whereas horses only assimilate about 

 18 per cent. 



The digestibility of any one food also varies very considerably, according 

 to the nature of the other feeds with which it is mixed. On account of the 

 great difficulty of accurately carrying out digestion experiments, the science 

 of the economical feeding of farm stock can only be said to be' in its infancy. 

 At the same time, we have sufficient data to enable any stock-feeder to com- 

 pound for his stock rations which shall be not only suitable for the purpose, 

 but economical, as opposed to the wasteful rule-of -thumb methods at present 

 too largely adopted. 



Dietary Standards. 



The composition of the ration will vary according to the animal to which 

 it is fed, its age, and the purpose to Avhich it is put. 



We have to distinguish between a maintenance diet — the diet required 

 for the animal when kept at rest or doing very light work — and that required 

 by an animal doing more severe work. 



Special rations are required for fattening animals, for dairy cows, for 

 young growing animals, and so forth, and the requirements of animals under 

 these different circumstances vary very considerably. 



It will readily be seen that the subject is a very wide one. It is one that 

 will amply repay a little careful study on the part of the farmer. In dairy- 

 farming, more particularly, feeding on rational lines is an essential to the 

 attainment of the best results. 



