vi Preface 



scriptions "to be given according to directions." It 

 is time to break away, if we have not already done 

 so, from an undiscriminating adherence to mathe- 

 matical doses of nutrients, the accuracy of which is 

 supposed by some to outweigh all other consider- 

 ations and to determine success in feeding. The 

 study of animal nutrition may not wisely center 

 around feeding standards, as seems to have been the 

 tendency of late years. While these formulas are 

 certainly an aid in selecting adequate and uniform 

 rations, they are nevertheless merely an imperfect 

 expression of relations not fully understood that have 

 a greatly variable application in practice, an appli- 

 cation judiciously made only through the exercise of 

 a judgment enlightened by familiarity with funda- 

 mental facts and principles. Rational cattle feeding 

 is not to be attained through a blind acceptance of 

 existing standard rations but by means of a broad 

 understanding of the scientific and practical knowl- 

 edge in which these standards had their rise. 



Much of the matter introduced in this connection 

 bears no immediate relation to the practical opera- 

 tions of feeding. No apology is made for this de- 

 parture from the business aspects of the subject. A 

 study of the practical relations of science should not 

 only promote our material well-being but should also 

 lend itself to intellectual stimulus and culture. 



