COLORS OF SHORT-HORN CATTLE 



Analysis of Genetic Factors Underlying Color Inheritance In Short- 

 Horn-Cattle 



Russell W. Duck 

 Animal Ilitsbaiidry Department, Syraeiise Unk'ersity 



TO WRITE a definite formula 

 that would fit all cases of Short- 

 Horn color inheritance is very 

 difficult. The problem is complicated 

 by the number of different recognized 

 colors : red, red and white, roan, and 

 white. It is also difficult to secure 

 accurate data from the herd books, be- 

 cause of the occasional blending of 

 these colors into one another, thus 

 giving conflicting ideas of the color in 

 question. This is influenced to some 

 extent by the popularity of the color. 

 Plumb' gives the relative proportion of 

 the different colors of Short-Horns at 

 two different periods, as shown in 

 Table I. The author computed the 

 colors of part of the animals registered 

 in the herd book in 1921. The records 

 of a total of 10,000 animals were 

 studied and the results obtained are 

 shown in the last column of the same 

 table. 



These tables show the decreasing 

 popularity of red-and-white. The 

 gradual elimination of herd bulls of 

 this color is having a considerable in- 

 fluence on the total number of red- 

 and-whites registered. The increasing 

 popularity of roans, and the frequent 

 selection of roan or white herd bulls 

 has materially increased the number of 

 roans registered in 1921 as compared 

 with those registered in 1859 and 191 4. 



In attempting to trace color inheri- 

 tance from the herd books one is im- 

 mediately confronted by the fact that 

 sources of error are probably very fre- 

 quent. Exact color classification is 

 extremely difficult ; occasionally animals 



^ Plumb, "Types and Breeds of Farm Ani 

 ^ Darwin, "The Variation of Animals and 

 ^Wentworth, American Breeders' Magazin 



65 



could be classified either as roan or as 

 red-and-white (see Fig. 3.) 



Secretary P. K. Groves of the Amer- 

 ican Short-Horn Breeders' Association 

 states that the rule of the Association 

 is to call all cattle roans if there is 

 roan coloring on any part of the body. 



According to Darwin", the wild white 

 cattle of Europe did not breed true, 

 and occasionally produced colored 

 calves, although these individuals were 

 never retained in the breeding herd. 

 In this respect the inheritance of white 

 is different from that in the Short- 

 Horn. A true white Short-Horn mated 

 to a true white Short-Horn will i)ro- 

 duce only whites. It is true that Went- 

 worth' presents cases of four reds and 

 eight roans produced from a cross of 

 white on white out of 153 matings. 

 However, this is entirely within the 

 probable limits of error. In tracing 

 186 matings of white on white, visit- 

 ing and corresponding with doubtful 

 cases, no case of true red, roan or 

 red-and-white was established. 



It was also established that red Short- 

 Horn cattle breed true. In tracing 

 2567 matings of this character no case 

 of pure white offspring was estab- 

 lished from true red on true red. In 

 cases where colors other than red are 

 recorded in offspring as a result of 

 crossing red on red, it will invariably 

 be found that one or both of the 

 parents were marked with white or else 

 that the offspring is incorrectly regis- 

 tered. 



The so-called "colors" roan and red- 

 and white of the Short-Horn are, 



mals". (Revised Edition). 

 Plants Under Domestication." 

 c. Vol. IV, No. 4. 



