6O2 



PRACTICAL PROBLEMS 



SECTION II GRADING 



By " grading " is meant the mating of a common or relatively 

 unimproved parent with one that is more highly improved, that 

 is, a "pure bred." The mating might be made either way, but 

 in practice the male is taken for the pure -bred parent for 

 economic reasons. One pure-bred bull with a herd of twenty 

 cows can give all the calves in the herd a pure-bred sire (that is, 

 make them half bloods), whereas if the making of half bloods 

 were attempted in the other way it would require twenty pure- 

 bred individuals, and the crop of calves would have no more 

 improvement ; besides which, the improvement made would be 

 not in one but in twenty lines, each with its shade of difference. 



Expressed in terms of money, it is possible to give all the 

 calves in a herd. a pure-bred sire that is, make them all half 

 bloods at a total cost of approximately two dollars per calf, 

 assuming, of course, a reasonable number of cows in the herd 

 and a bull at a moderate price but good enough for grading. If 

 the making of half-blood calves were accomplished in the other 

 way, however, that is, by providing the pure -bred parent on the 

 dam's side, it would cost, at the same relative rate, close to 

 forty dollars as a minimum. This shows the necessarily extreme 

 cost of pure breds as compared with grades. 



DISAPPEARANCE OF UNIMPROVED BLOOD BY THE CONTINUOUS USE 

 OF PURE-BRED SIRES 



Improvement by grading is of course limited to herd improve- 

 ment. It adds nothing to the breed, but it distributes breed 



