THE INHERITANCE OF DEGREES OF 

 SPOTTING IN HOLSTEIN CATTLE 



L. C. Dunn, H. F. Webb and M. Schneider 

 Starrs Af/riciilfttra! Rxpcriinoit Station 



HOLSTEIN cattle, with their 

 striking- black and white col- 

 oration, are familiar features of 

 almost every country landscape. Pure- 

 bred Holsteins in the United States 

 outnumber all other kinds of purebred 

 dairy cattle combined and supply the 

 greater portion of the milk and dairy 

 products consumed in this country. 

 In addition to mere numbers, they are 

 interesting to the student of natural 

 history because of the great variety of 

 coat patterns in existence. Unlike 

 other breeds, they have never been 

 made to conform to a rigid standard 

 of pattern. In fact, Holstein breeders 

 have rather prided themselves on the 

 absence of requirements in regard to 

 coat pattern and have preferred to 

 direct their breeding operations toward 

 the perfection of a valuable milk pro- 

 ducing type, uninfluenced by minor 

 considerations of pigmentation. The 

 only registry requirements relating to 

 spotting are that the animal to be reg- 

 istered must be black and white ; and 

 that the following extremes of spotting 

 are barred from registration: (1) solid 

 black. (2) solid white. (3) black 

 switch. (4) solid black with white only 

 under belly, (6) black on legs begin- 

 ning at feet and extending to kness 

 and hocks or black with white inter- 

 spersed in these parts. The relative 

 amounts of black and white may and 

 do vary within wide limits from nearly 

 all white v»^ith black eyes, to almost 

 solid black with traces of white on the 

 extremities or belly. There has been 

 of late years a tendency for some Hol- 

 stein breeders to prefer the lighter 

 types, while a few have favored the 

 very dark types. These preferences 

 have not been general and they have 



^Contributions in Genetics No. 16. 



not influenced the breeding operations 

 nor changed the general character of 

 the breed to any marked degree. 



The occurrence of nearly all degrees 

 of black and white spotting provides 

 additional marks of identification of 

 the individual animals. Breeders have 

 taken advantage of this fact and have 

 kept sketch records of the spotting of 

 each animal, and have made wide use 

 of photographic methods for recording 

 the type and coloration of their cattle. 

 The Holstein-Friesian Association, 

 which is the official registry office for 

 this breed, now requires a standard- 

 ized sketch of each animal submitted 

 for registry and when one considers 

 that over one million purebred animals 

 have been registered, each entry ac- 

 companied by a descriptive sketch and 

 a statement identifying both parents 

 of the animal, the bulk and value of 

 these records may be readily recog- 

 nized. 



In view of this wealth of interesting 

 material, we were somewhat surprised 

 to find, about a year ago, that the in- 

 heritance of the variations in the coat 

 pattern of this breed had never been 

 investigated. We decided to attempt 

 such an investigation and Mr. Webb, 

 then a student in the Connecticut Agri- 

 cultural College, undertook to gather 

 the necessary data as thesis material 

 for an advanced course in genetics. 

 He met with prompt and courteous co- 

 operation from the officers of the Hol- 

 stein-Friesian Association who placed 

 the material in their registry office at 

 Brattleboro, Vermont, at his disposal. 

 It is also a pleasure to acknowledge 

 here the help and suggestions of Pro- 

 fessor G. C. White and Mr. L. M. 

 Chapman of the Dairy Department of 



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