Kuiper: Color Inheritance in Cattle 



107 



THE MOST COMMON TYPE OF CALF 



This type and the one shown on the opposite page are the most common types produced by 

 mating a heterozygous Belted bull with piebald cows. The coat pattern possessed by these 

 cattle is of no commercial importance. Breeding to get the desired pattern has produced 

 a decline in the general output of the animals. The above illustration is from an original photo- 

 graph which unfortunately was so dim that retouching was necessary to bring out the details. 

 (Fig. 7.) 



GENETIC COMPOSITION 



The breeding of Belted Cattle has 

 of late years come to be disregarded in 

 Holland. Only a very limited number 

 of breeders have kept up this breed, 

 and then mostly as "Park Cattle" 

 (ornamental cattle). The complaint 

 has frequently been made that owing 

 to breeding with the exclusive view of 

 obtaining the desired pattern, the gen- 

 eral appearance and output of the 

 animals was declining. Hence breeders 

 often tried to improve these defects by 

 the infusion of blood from a pied 

 strain. This could be done, because 

 the belt character is dominant or pre- 

 potent, as it is called. Thus it is not 

 too bold to assume that Belted Cattle 

 are to a not inconsiderable extent 

 heterozygous as regards the belt char- 

 acter. The pied cattle which are bred 

 thoroughly pure are undoubtedly 

 homozygous as regards the piebald 

 factor. 



In explaining our experiment with 

 the heifers I assume, therefore, that 

 the heifers formed a homogeneous popu- 

 lation as far as this factor is concerned, 

 while the bull is to be considered 

 heterozygous. Seeing that Mr. Joch- 

 ems found the sire and the grandsire 

 of this animal to produce plain black 

 calves when purebred, this assumption 

 is not hazardous. 



Let us now assume two pairs of 

 factors, viz. : 



B=belt b = absence of belt 



S = self-colored . . . .s = not self-colored: 

 piebald pattern. 



The numerical relation resulting 

 from the experiment may be accounted 

 for by assuming a repulsion between 

 the factors B and S in accordance with 

 the reduplication series, 1:7:7:1. If 

 our bull answers to the formula, BbSs, 

 he forms gametes in the proportion of 

 lBS:7Bs:7bS:lbs. 



