HEREDITY; ITS MEANING AND INFLUENCE 225 



directly concern the stockman are the following: (a) Color 

 markings. One of the most important features of breed 

 identification is the color. Some breeds possess a solid, 

 uniform color, as the red of the Red Polled cattle, the black 

 of the Aberdeen Angus, the white of the Chester White and 

 Large Yorkshire pigs, and the red of the Duroc-Jersey. 

 Each breed has its standard color or colors, and anything 

 varying from this, as a rule, causes disqualification, (b) 

 Milk production. The Holstein-Friesian breed is noted for 



Fig. 141. A good example of fecundity. A Duroc-Jersey sow and litter of 14 

 pigs. Photograph by courtesy Ohio Agr. Exp. Station. 



the large milk flow of the cows. No other breed of cows 

 equal these in heavy flow of milk, and no feature does more 

 to make the Holstein-Friesian famous than that of milk 

 production, (c) Fecundity is especially a hereditary char- 

 acter. Shropshire sheep have been noted for many years for 

 the large percentage of twins dropped by the ewes. The 

 Large Yorkshire and the Tamworth breeds of hogs are famous 

 for the large litters farrowed by the sows, while of the lard- 

 type breeds, the Duroc-Jersey is prominent in this respect, 

 (d) Temperament. As a rule, animals of a heavy, fleshy 



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