396 Report of Farmers' Institutes 



The modern tendency in dairy cattle breeding has been decidedly 

 away from the Bates or dual-purpose type of dairy cow. Expe- 

 rience has demonstrated fully that with exceptional care the 

 specialized dairy cow is more efficient in the production of food 

 products than the intermediate dual-purpose cow. While a few 

 geneticists maintain that it is possible to obtain both maximum 

 milk secretion and beef production from the same animal, I 

 believe the recent knowledge obtained regarding milk secretion 

 will show the fallacy of this contention. 



We have in this country several w^ell-defined and specialized 

 dairy breeds, and the improvement in their production has been 

 very rapid indeed. Probably much of this improvement has been 

 due to our knowledge of feeding and care, but a great deal also 

 has been accomplished by breeding. Our systems of breeding have 

 been largely based on the principle of " mass selection," that is, 

 selecting our breeding stock from the high-producing animals. 

 This is apparent from our methods of keeping records, our cow- 

 testing associations, our selection by means of the score card, and 

 the high prices paid for high-producing females and their 

 offspring. 



The work of Johannsen pointed pretty definitely to the limits 

 and possibilities of improvement by selection — that it is only a 

 screen by which the poorer animals of a breed may be eliminated 

 and the good ones kept ; that it is not possible to obtain any added 

 improvement by this method. This is in accord with the records 

 of many of our experiment station herds all over the world. These 

 records show that the average production of cows through a series 

 of years fluctuates, and may or may not be better .after several 

 years' breeding where all possible care has been exercised in the 

 selection of breeding sires. 



We now recognize that mass selection not only does not 

 give added improvement to a breed, but does not permit of the 

 maximum improvement that is possible in animal selection. 

 While it is not possible to isolate lines of inheritance and to insure 

 their transmission with such certainty in dairy cattle as it may 

 be with some plants, it is possible to apply those principles to a 

 much larger degree than we have applied them in the past. Owing 



