


STANDARD RATIONS FOR DAIRY COWS. Il3 
needs of the animal, but often does not. It considers mainly 
the relative cost of feeding stuffs and the amount and value of 
the product obtained from their use. 
A third so-called “‘standard ration’’ is based upon the aver- 
age practice of a large number of feeders; in other words, it 
expresses the average of a large number of rations found in 
actual use. 
The confusion of terms might be avoided by making the 
term “standard ration’’ refer only to the physiological standard, 
while the second so-called standard might be designated as a 
Jormula for profit, and the third might be called an average 
feeding ration as found in practice. In the discussion of 
standard rations and formulas in the present article, this classi- 
| fication of terms will be followed. 
Phystological standards.—We have here practically two phys- 
iological uses of food to consider, namely for maintenance and 
for production. The amounts and proportions of the different 
nutrients required to keep up the vital functions of the animal, 
that is to say, for maintenance, and those needed for production 
of milk, meat, work and the like, have been quite extensively 
studied by European experimenters. Using the results of such 
experiments and of more general studies of the laws of nutri- 
tion, several German authorities have proposed standard rations 
for milk production. The most commonly quoted of these is 
Wolff’s, which calls for 2.5 pounds of digestible protein, .4 
pounds of digestible fat, 12.5 pounds of digestible carbohy- 
drates, per 1000 pounds live weight, and has a nutritive ratio 
of 1:5.4. While Prof. Wolff does not insist upon the distinction 
between physiological standards and formulas for feeding, his 
standard is recommended as representing, in a general way, the 
proportions which will be profitable for German feeders. He, 
however, urges the impracticability of establishing any fixed 
‘standard for profit that would apply to the feeding of animals 
under widely varying conditons. 
Prof. Julius Kuhn, another well-known German authority, 
has very cleverly pointed out the limitations in the use of feed- 
ing standards, although he insists upon their great value when 
properly used.* He insists upon the necessity of studying the 

* See Experiment Station Record, Vol. IV., p. 6. 
