No. 4.] DAIRY CATTLE. 67 



Breeding Dairy Cattle. 



The subject of breeding is a great deep, which in many 

 of its phases has never yet been fathomed. But it has its 

 shallows as well, and it is in these that I propose to conduct 

 my search. Aside from the laws or principles which govern 

 atavism and correlation are two laws or principles, some 

 knowledge of which is essential to the successful breeding of 

 farm animals. These are : first, the law or principle that 

 like produces like ; and second, the law or principle that like 

 doesn't always produce like. Some claim that these do not 

 have the strength of law, they vary so much in the results. 

 I will not argue that question here. It is sufficient for my 

 purpose to know that it is within the power of the breeder 

 to accelerate likeness of transmission, or to retard it. Once 

 grant this, — and it cannot be denied, — and you at once 

 give the breeder the power to raise the standard of his herd. 



Certainty in likeness of transmission is increased, at least 

 up to a certain limit, by increase in purity in the blood ; by 

 increase in prepotency, in the sire especially ; and by the 

 continual weeding out and discarding of undesirable variants. 



The advice is freely given to those who desire to improve 

 their herds, that they shall do so by using only a pure-bred 

 sire, well chosen as to his individuality. This advice is based 

 on the observed fact that resemblances to such a parent in the 

 progeny are greater than could be looked for from a male of 

 mixed breeding. Theoretically, every generation added to 

 the pedigree would add to the certainty of the transmission; 

 but this may not always follow, because of variations that 

 occurred in the ancestry. The comparison between using sires 

 of pure and mixed blood may be stated as follows : from the 

 pure sire there may occur some variations that are not de- 

 sirable ; from the other sire they will certainly occur. In the 

 former blood, elements have been strengthened and made 

 dominant in transmission through repetition; in the latter, 

 they have not. 



If, therefore, length of pedigree beyond a certain limit is 

 not an infallible measure of the value of pedigree, what is 

 the measure of such value, viewed apart from the individual 



