330 



The Journal of Heredity 



A PRACTICAL PROBLEM FOR SWINE BREEDERS 



Here is a pair of pure-pedigree Hampshire sisters from Dr. Flower's herd. The one at the right 

 represents the standard pattern, the other shows an enlargement of the white belt until 

 it covers the whole body, save for the head and tail. How can such an excess of white be 

 corrected in V^reeding? Mr. Simpson says some breeders have used an all-black "throw- 

 out" male for mating with sows of this type, and the results in the first generation are 

 suceesful. Relief is only temporary, however, for the second and tliird generations break 

 away into black and white "throw-outs," just as is the case with Blue Andalusian chickens. 

 (Fig. 1.) 



outside area that delineates it. Then 

 we might say that the white belt of 

 swine is composed of a single factor, this 

 dominant, and being simply the same 

 factor that can ])roduce a rather low 

 potential of dominant white. But when 

 a Belt is crossed, or white added, with 

 breeds that exhiV)it, or carry latent, 

 spots in the pigment area, it must then 

 be compounded of two factors: one the 

 white, the other a determiner for sclfing 

 the ]Mgmented portion of the pattern. 

 The first of these factors (the white) is 

 dominant; the second (the sclfing) is 

 recessive. 



Spotting on swine, as with other 

 mammals, may be of two kinds: ])ig- 

 mcnt spots on a white field, and white 

 spots on a colored field. I can readily 

 recall the founding of a noted breed of 

 swine that was white with small black 

 spots but now, by the selective fancy 



of its breeders, has gone through such 

 an evolution that it has become nearly 

 pure black, with a few white spots. 



INHERITANCE OF BELT. 



With a pure Ham])shirc male from 

 President (^ood wine, the white area of belt 

 was dominant over some pure lorceds, 

 but in lower per cent, with cross-brcds. 

 The sclfing was of vascillating reces- 

 siveness, verging to dominant in some 

 crosses. From this boar on a pedigree 

 Poland-China sow, that was clean black 

 exce])t the six white points, a brood of 

 13 ]ngs was born, all clean while in the 

 belt of fairly uniform width; but seven 

 of the litter were so mtich coxered with 

 s]xjtting in the desired black area that 

 they would not be taken for Hampshire 

 hybrids. 



As would be expected of white-face, 

 stocking-legs, sjiotting, or pattern dc- 



