THE DAIRY HERD 21 



speedily fix desirable characters by close breeding. In- 

 and-in breeding can be practiced with success, however, 

 only in the hands of skilled breeders. 



In the case of crossing one breed upon another as, for 

 example, a Holstein-Friesian upon a Jersey, it is often 

 mistakenly supposed that the progeny of such a cross 

 partakes equally of the characters of both parents. This 

 may occur in some instances, but more often the offspring 

 will resemble either one parent or the other, or neither. 

 But even where the offspring does partake equally of the 

 characters of both parents, such a cross is undesirable 

 because the offspring is not capable of transmitting its 

 characteristics with any degree of certainty. In the hands 

 of the average dairyman transmission in crossing is uncer- 

 tain and unsatisfactory, and for this reason crossing 

 should not be attempted. 



When a cow of nondescript or promiscuous breeding is 

 bred to a pure-bred sire, the progeny will largely partake 

 of the characters of the sire, by reason of his greater 

 prepotency. With what degree of regularity and to what 

 extent this occurs depends upon the degree of prepotency. 

 The offspring of a highly prepotent sire and a common or 

 native cow will take on nearly all the essential character- 

 istics of the sire. In such a case it is plainly seen that the 

 sire counts for a great deal more than half the herd. 



In the case of grade cows the influence of the pure- 

 bred bull becomes less the closer the grade approaches 

 purity of blood. But only in the case where the cows are 

 pure-bred, or more strictly of equal prepotency with the 

 bull, can it be said that the bull is only half the herd. 



Similarity of Parents. In mating animals it should 

 always be remembered that the greater the similarity of all 

 their characteristics the greater the certainty of trans- 



