Lush: Inheritance in Swine 



59 



A WILD BOAR AND ONE OF HIS PROGENY FROM A DOMESTIC TAMWORTH SOW 



European wild boars were used in these breeding experiments to determine the inheritance of 

 litter size. Wild sows ordinarily produce only about four pigs per litter which is much less than is 

 produced by sows of the domestic breeds. Tamworths farrow on the average about eleven pigs. 

 The picture shows the wild boar used (at the right) with one of his crossbred sons. (Fig. 7.) 



production of its own peculiar ear 

 shape; i.e., being purebred is not equiv- 

 alent to being homozygous in this 

 respect. 



SHAPE OF FACE 



This character, like the set of ear, 

 does not complete its development until 

 the animal is mature, and is fairly 

 constant within each of the breeds of 

 swine. Both the Tamworth and the 

 wild hog are characterized by long 

 narrow straight faces with no forehead 

 prominence. The Wild face is the more 

 extreme in each of these three respects, 

 and the seven mature Fi pigs all ap- 

 proach very closely to the face shape 

 of their wild parent. 



Among the common breeds of swine 

 in America the Berkshire represents the 

 opposite extreme to the wild hog in 



face shape, having a very short, ex- 

 tremely dished face and a forehead so 

 broad and prominent as to give it a 

 sort of pompadour appearance. Only 

 two pigs from the Wild X Berkshire 

 cross matured and both resembled the 

 wild parent so closely that, except for 

 color and wider foreheads, they would 

 have been indistinguishable from the 

 Wild X Tamworth Fi's. 



Seven pigs of the Fi generation of the 

 Berkshire X Tamworth cross matured 

 and could not be distinguished from the 

 purebred Tamworths as far as face 

 shape was concerned. This is espe- 

 cially surprising because Simpson^ who 

 crossed Tamworths and Large York- 

 shires (which have a face shape similar 

 to the Berkshire in outline although 

 longer), reported that the result was 

 an intermediate face shape. He does 



'Simpson, Q. I. and J. P. 1909. Am. Breeders' Association, Vol. 5, pp. 250-5. 



