CROSS BREEDING. 325 



of sheep owe their origin in part from this method of breed- 

 ing. The same thing is true of our breeds of swine, while 

 the same method has been practiced in a small measure at 

 least in the building up and improvement of our many breeds 

 of horses and cattle. 



In the foundation and improvement of the breeds of stock 

 crossing was introduced for various purposes. In some in- 

 stances where the animals of one breed were under-sized, by 

 the introduction of a cross from some new breed which was 

 noted for its size this difficulty could be remedied. In the 

 same way many other weaknesses in the breeds were over- 

 come. Certain of our dual purpose breeds of cattle were built 

 up by the crossing of two breads; one noted for its dairy prop- 

 erties and the other for its beef making qualities. To this 

 class belongs the Red Polls of today. 



In swine breeding if a breed were lacking in length, size 

 or some other point a cross from some other breed which was 

 strong in these points was introduced. In this way much 

 good was accomplished. The crossing of pure breeds in this 

 country is practiced to a considerable extent. In most in- 

 stances it is being used as a short cut to some desired end. 

 For instance, with the hope of increasing the length of certain 

 breeds of hogs, or to increase the bone or the size of the litter 

 in those breeds which are under-sized or inclined to produce 

 small litters. It is also used in a similar way with the hope 

 of improving our sheep, cattle and horses. 



In many instances the first cross gives very good results 

 where the offspring are intended for market purposes. They 

 oftentimes are an improvement over either sire or dam. This 

 method is very unsatisfactory where the young are intended 

 for breeding purposes, as then you must either go one way or 

 the other. For the purpose of producing market animals, it 

 is not to be commended, as it is too expensive, involving as it 

 does the purchase of new breeding stock from time to time 

 as the cross-bred animals do not make desirable breeding 

 animals. 



As previously stated, it is used with the hope of making a 

 short cut to some desired end. This same end can usually be 

 obtained by careful selection, feeding and management of the 

 stock on hand. There is always a cause for retrogression 

 in stock. The cause should be removed and new blood of the 

 same blood introduced rather than resorting to the uncertain 

 method of cross-breeding. 



