72 BOARD OF AGRICULTURE. [Pub. Doc. 



cent, and a new element, the Jersey blood, would have to be 

 reckoned with. Those, therefore, who are continually chang- 

 ing the breed of the sire are like the mariner who sails without 

 a compass. 



But it may be asked, Are there no instances in which it 

 would be advantageous to use a sire of another breed ? Such 

 instances may arise, but when they do the breeder has a 

 specific purpose in view, and having introduced the outcross, 

 so to speak, he goes back again to his old line of breeding. 

 For instance, a dairyman may have in his herd high-grade 

 Jerseys. They may be too small in size and delicate in form 

 to suit his fancy. He introduces a brown Swiss sire, and then 

 goes back to the use of Jersey sires. I am not to be under- 

 stood as indorsing the frequent recourse to such crossing, but 

 simply as showing that there may be a place for it. 



To the kind of upgrading advocated above it has been ob- 

 jected that, while the first cross brings improvement, the 

 second cross will show retrogression, at least in many in- 

 stances. That is not true, except in the case of animals prac- 

 tically pure in breeding. It is the outcome to some extent 

 at least of a conflict of potency in the blood elements, out of 

 which come tendencies to reversion. Where the blood ele- 

 ments are much mixed on one side and are strong and un- 

 adulterated on the other, no such conflict can exist. Where 

 the feeding and management are good, there should be im- 

 provement with each succeeding cross until that point is 

 reached when the progeny will in appearance be the equal of 

 the animals of the breed from which the sires have been 

 chosen. 



But will the improvement be as great, it may be asked, 

 in milk production as in form under such a system of up- 

 grading? I answer, K"o. How much less will it be? I 

 cannot tell. I think the statement safe that claims a longer 

 time to make change through transmission in function than 

 through transmission in form. Thus it is that increase in 

 milk-giving capacity will not be equal to the change made in 

 form; and thus it is that a much longer time is called for 

 to change the character of the wool fibers in sheep than to 

 change the form thai bears them. 



