306 ANIMAL HUSBANDRY 



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given us improved animals. The predecessors of the modern 

 plump and well-rounde/1 beef steer were not handsome or well- 

 formed; the razor-back scrub hog stands as a mute witness of the 

 wonderful difference existing between him and the well-developed 

 specimens of the market hogs; while horses and other domestic 

 animals show developments equally great. 



These changes have been brought about mainly by selection of 

 the best individuals having certain marked characteristics, care- 

 fully mating these individuals, and giving them favorable environ- 

 ment. When a group of animals is secured of marked resemblances 

 and the offspring inherit the same qualities and characteristics, the 

 variety or group is designated as a breed. In improving farm ani- 

 mals the stock raiser may have one of three objects in view: 

 (1) to improve the herd or the home stock of the farm, (2) to im- 

 prove the breed as a whole, (3) to originate new breeds. 



Improving Scrub or Mixed Stock. By grading up his herd or 

 flock with animals of some distinct breed the owner may make it 

 compare quite favorably with the recognized breed. 



Improving the Breed as a Whole. Many stock raisers work 

 chiefly for the improvement of a recognized breed. Individual 

 animals having the regular type characteristics most strongly 

 developed are selected and mated from time to time until a 

 good breed is developed. This method of breeding calls for con- 

 siderable skill and intelligence and is somewhat expensive. 



Originating New Types. Some stock raisers, in place of trying 

 to improve existing breeds, spend their time and energy in dis- 

 covering and developing new types. Animals, like plants, fre- 

 quently develop individuals showing marked variations from the 

 parent type. By properly selecting a number of individuals 

 showing the desired variation and properly mating their offspring, 

 a breed may eventually be developed which will tend to come true 

 to the type. The origination of Polled Durham cattle, Poland 

 China, Duroc Jersey, and Chester White swine in our own country 

 demonstrates what may be done in originating new breeds by 

 improving or amalgamating older breeds. Scientific knowledge 

 seems likely to facilitate this work in the future. 



Pure-bred Stock. Pure-bred animals are those whose parents 

 belong to the same breed. 



