512 GENETICS IN RELATION TO AGRICULTURE 



in all points of comparison with her dam. She was easily the most ex- 

 ceptional individual reported upon in the investigations; so that there is 

 evidently no lack of excellence in the Guernsey breed for grading up 

 dairy herds. Finally in the third lot, which consists of two individuals, 

 a scrub cow and her grade Jersey daughter, when the immaturity of the 

 latter is taken into account, a substantial improvement is displayed. 

 The numbers in these investigations so far are not large, but they do 

 show that enough improvement results from the use of good pure-bred 

 sires to warrant fully the increased expenditure necessary to obtain them. 



In grading, however, as in all other forms of animal breeding, it is 

 necessary to observe all the precautions which have been found necessary 

 for effecting permanent improvement. These may be stated in the fol- 

 lowing general fashion. 



The Sires Used in Successive Generations Must Belong to the Same 

 Breed. It may be to the best financial interests of the stockman some- 

 times to breed to a sire of a different breed from the one used in grading, 

 but, if that should be done, the cross-bred stock thus produced should not 

 be retained for breeding purposes. There are several reasons for insist- 

 ing upon strict adherence to such a plan of operations, and they have 

 to do mainly with uniformity of the finished product, a requirement 

 which can only be met by following a definite, consistent line of procedure. 

 If such be followed, the result is to make the herd in the fourth generation 

 practically pure bred so far as purposes of utility are concerned. In 

 fact, such grade herds, freed as they are from the dictates of fashion 

 which often prevail within breeds, are often superior in actual produc- 

 tive capacity to pure-bred herds. 



The Sires should be Selected with Strict Regard for the Improvement 

 which It is Desired to Effect within the Herd. It is not enough to use 

 any individual of the breed upon which the choice has been set, for 

 paradoxical as it may seem there are some pure-bred mongrels. Within 

 most breeds there are families which are notable for certain definite charac- 

 teristics. In the interests of uniformity, therefore, the series of sires 

 which is selected should ordinarily belong to the same family : they should 

 at least conform to a single, specific type. Furthermore, the sire should 

 be a superior specimen of his breed. The man who desires to improve a 

 grade herd can afford to neglect fancy points entirely, but conformance 

 to high utility standards should be insisted upon. Among dairy cattle 

 advanced registration records based upon performance are excellent 

 indices for judging the possible value of individuals in grading. In other 

 breeds of livestock an approximation can and should be made to standards 

 of excellence based upon performance. 



Dams should be Selected Strictly According to a Definite Utili- 

 tarian Standard. The rate and extent of improvement in a grade herd 



