ENERGY VALUES OF RATIONS FOR FARM ANIMALS, 19 
matter shown in the first column of the table on pages 11-13. In very 
general terms it may be said that a 1,000-pound ruminant should be 
given from 20 to 30 pounds of dry matter per day, 25 pounds being 
perhaps a fair average, while for the horse smaller amounts will be 
appropriate. 
A study of the table shows that concentrated feeding stuffs contain 
much more protein and energy in proportion to their dry matter than 
do the forage crops. Evidently, then, in heavy feeding, where the 
purpose is to give the animal all the feed possible, the ration should 
consist as largely as practicable of concentrated feeding stuffs, be- 
cause only in that way can the required amount of nutriment be ob- 
tained without unduly increasing the bulk of the ration. On the other 
hand, in light feeding the coarse fodders may predominate, because 
they are usually relatively cheaper and can supply the required 
amount of nutriment in a bulk which the animal can consume. 
THE COMPUTATION OF RATIONS. 
GENERAL CONSIDERATIONS. 
In the foregoing pages we have considered the requirements of the 
animal machine for repair material (protein), and for fuel material 
(energy), and have also studied the feed as a source of these two. 
If we knew exactly the requirements of the animal in any given case, 
and if we knew exactly what amounts of protein and energy the feed- 
ing stuffs at our disposal could furnish, the computation of a ration 
would be almost purely a matter of arithmetic. We would simply 
have to devise a mixture of the feeding stuffs which would yieid the 
requisite amounts of protein and energy and would at the same time 
be of suitable bulk and of such a character as to exert no injurious 
action upon the animal. 
As a matter of fact, we have no such exact knowledge. Practi- 
cally, animals vary in their requirements, while feeding stuffs of the 
same name show a wide range in composition, digestibility, and 
nutritive value. Furthermore, what is still more important, the 
economic conditions vary from case to case so that, for example, a 
very liberal ration might be advisable in one instance, while for the 
same animal under different conditions it would be highly uneco- 
nomic. The figures given on previous pages can not be made the 
basis of infallible recipes which shall save the user the trouble of 
observing and thinking. 
But notwithstanding all this, the foregoing data can afford valu- 
able aid to the feeder. By their use he can get a general idea of 
the feed requirements of his animals and can compute a ration which 
will approximately supply the requisite amounts of protein and 
energy. His ability as a feeder will be shown, first, in his power 
