AGRICULTURAL EXPERIMENT STATIONS. 275 



been actively prosecuted for some ten years as to the digesti- 

 bility of different foods ; not with reference simply to what 

 proportion of hay or potatoes or cotton-seed meal is dissolved 

 and consumed in gross, but Avhat proportions of the fat, of 

 the starch, of the albuminoids, of the fibre, of the phosphates, 

 etc., are utilized as nutriment. These investigations are 

 made by feeding known quantities of analyzed food, keeping 

 account of o:ain or loss of live weight, and also collectino-, 

 weighing and analyzing the urine and dung. What enters 

 the animal as food, that cannot be found again unaltered in 

 the excrement, has been digested. 



The digestibility of a given cattle-food is not invariable, 

 but changes according to the kind of animal, and the articles 

 that accompany it in the ration ; but by numerous experi- 

 ments it is expected that a series of average figures will be 

 obtained which will serve usefully as a basis for estimating 

 the relative values of different feeding stuffs. 



One of the interesting results of these researches is, that 

 the fibre or cellulose — the ver}' wood — of plants is to a con- 

 siderable degree digestible. It has "always" been known 

 that the beaver subsists on wood and bark during winter, 

 that cattle derive great satisfaction from browse, and that 

 goats will eat newspapers and cotton cloth. Exact trials 

 have shown that sheep are able to digest a large proportion 

 of sawdust and of pure paper pulp, and that all farm animals 

 readily convert into food from 40 to 70 per cent, of the fibre 

 or woody matter of hay, straw and chaiF. In fact, these 

 materials have been proved to be not simply digestible "on a 

 pinch," but really serviceable to a corresponding degree with 

 starch, sugar, oil, etc. Accordingly, in most of the well com- 

 pounded cattle rations, the second rank in respect to quantity 

 is occupied by cellulose or "crude fibre." 



It is remarkable how differently the same elements of various 

 kinds of forage submit to digestive action, as exhibited in the 

 following results of this class of experiments : 



