Lush: Inheritance in Swine 



65 



A BERKSHIRE X DUROC- JERSEY CROSS 



An example of the re-appearance in the second generation (Berkshire XDuroc-Jersey) of a long 

 straight face similar to that of the Duroc-Jersey. The first cross was closer to the Berkshire than 

 to the Duroc-Jersey in length and dish of face and shape of forehead. Various combinations 

 segregated out in the second generation. (Fig. 14.) 



stripes were brown and sandy on all 

 the thirty-eight pigs produced by cros- 

 sing the wild boars upon purebred Tam- 

 worth sows. They were quite uniform 

 in color. However, on the seventeen 

 pigs produced by crossing the wild 

 boars on purebred Berkshire sows, 

 the bellies and light stripes were a 

 very light sandy, almost white, and 

 the darker stripes were a darker 

 brown; that is, there was less of a 

 reddish tinge throughout and, in addi- 

 tion, there were large black spots 

 scattered all along the whole under 

 surface. This is most readily in- 

 terpreted as meaning that the wild 

 pattern is not completely epistatic but 

 lets the Berkshire black spots develop 

 along the underline and allows the 

 Tamworth red to show up in the red- 

 dish tinge of the offspring from that 

 cross. 



Four F2 pigs, all striped but of dif- 

 ferent belly colors, were produced in 

 the Wild X Tamworth cross. One had 

 a very light, almost white, belly (pre- 

 sumably lacking the Tamworth factor 

 or factors for red), two were like the FiS, 

 and one was like the FiS except that it 

 had some large black spots in both hair 

 and skin scattered along its belly. 

 There was one backcross litter by an Fi 

 boar of a purebred Tamworth sow. 

 Three of these were faintly striped and 

 possessed small black spots on their 

 bodies, two were like the Fis, two 

 were red with small black spots, 

 and one was self red. This seems to 

 mean at least two independent factors 

 — one for black spots and one for the 

 striping pattern — and another factor 

 for intensity of the striping which 

 may be linked to the factor for black 

 spots. 



