No. 4.] SALT MAIISH HAY. 35 



But there is another fact to be considered, namely the 

 digestibility of fodders. Not all of the hay and grain that 

 enters the stomach is food ; a portion passes unchanged from 

 the mow and bin to the manure pile, and is no more food 

 than the rock and shale found in our coal is fuel. It is only 

 that part of the fodder that is made soluble in the process of 

 digestion that is food in the true sense of that word ; hence 

 we have the results of thousands of experiments designed to 

 determine the digestibility of the long list of fodder articles. 



I have said that food may be classed under two heads : 

 nitrogenous (having a large amount of albuminoids), and 

 non-nitrogenous or starchy. This is possible because it has 

 been found that digestible starch, sugar, fibre and oil are put 

 to the same use in the animal system, and it is a matter of 

 indifference whether we feed a pound of sugar or a pound 

 of starch ; oil, while the same in kind, is more eft'ective 

 pound for pound, and scientists rate a pound of oil equal to 

 from one and three-fourths to two and one-half pounds of 

 starch ; so that in all subsequent use of the chemical compo- 

 sition of food I shall speak of digestible albuminoids and 

 digestible non-albuminoids, including under the latter starch, 

 sugar, fibre and oil, the oil being multiplied by two and one- 

 half, to bring it up to its equivalent in starch. 



Uses of Food. 



The animal consumes food to sustain life, we say ; but by 

 this we mean that there are three great uses for food in the 

 animal body : to maintain the bodily temperature at 100 ° ; to 

 supply the energy which shall enable the animal to move 

 from place to place or draw loads or exert itself in any way ; 

 and, last, to produce growth, whether of new tissues to 

 replace worn-out ones, or to give increased bodily weight, or 

 to produce milk, meat, eggs, etc. 



Keturning now to a consideration of what the animal 

 requires, and we have the results of the German scientists, 

 who, after first experimentally determining the ration or 

 rations that in practice produced the best results, next deter- 

 mined how much actual food, that is, digestible matter, these 

 rations contained: and thev found under these conditions 

 that for a cow weighing one thousand pounds, and giving 



