STANDARDS FOR RATIONS AND DIETARIES. 207 
WRONG USE OF FEEDING STANDARDS. 
The thing against which I wish to protest first of all is the 
inconsiderate use of feeding standards. To read articles which 
appear by the hundred, not only in the columns of the press, but 
even in some of our Experiment Station Reports, one would 
think that the science of cattle-feeding was a branch of applied 
mathematics, the data for calculations being found in the tables 
for composition of feeding stuffs, and the formulas in feeding 
standards. We are told, practically, with a constancy of repeti- 
tion which is worse than tiresome, that for feeding a milch cow, 
for instance, we want per thousand pounds of live weight so and 
so many pounds of protein and other nutrients per day; that dif- 
ferent feeding stuffs contain such and such percentages, that is 
to say, so and so many pounds per hundred of these nutrients; 
and that, to get a proper daily ration for a cow we must first 
select our food materials, then take their proportions of nutrients, 
and figure out quantities that fit the standard. By this calcula- 
tion, which is perhaps a little abstruse to the average dairyman, 
but in which to-day there is no lack of mathematicians, chemists, 
and physiologists to help-him, he may easily make his calcula- 
tions; or, if he does not care to take this trouble, he may find 
them ready made and in the greatest abundance. 
Iam well aware that to say this and to put it so strongly is to 
expose myself to the severe charge of being the first man on this 
side of the Atlantic to use this method of calculating rations. It 
may be very true that the enthusiastic young student, fresh from 
studies in Europe, where this doctrine originated, was indiscreet 
in not emphasizing more clearly than he did that standards for . 
tations are only approximations, and very rough ones at that; 
that at best they could only represent very general averages; that 
the variation in the composition of food stuffs of the same kind 
were so wide that no averages of analyses could apply to all 
cases; that the analyses were extremely imperfect representations 
of actual nutritive values; that we did not know exactly how the 
‘nutrients are used in the body; that it is impossible to lay down 
an accurate physiological standard for animals of any given kind; 
that differences, not only of species and of breed but differences 
of individuals of the same breed are so wide as to make an 
accurate physiological standard out of the question; and that 
even if the physiological standard were rightly determined the 
