Dunn, Schneider and \\'el)b : Spotlino- in Cattle 



231 



AVERAGE DEGREE OF SPOTTING OF THE LIGHT SIRE'S DAUGHTERS 



Figure Hi. This daughter of King Model (Bloomingdale Model Ormsby Segis 598203), 

 shows the average grade of his daughters by all grades of cows. She has 201 units of black 

 (about twenty-one per cent) on each side of the body. In all three bulls studied, the average 

 color of offspring was intermediate between the grade of the sire and the avearge grade of 

 the dams. Photograph courtesy of Bloomingdale Farms, Somerville, N. J. 



least. Because of the small numlDer of 

 recorded offspring which could be ob- 

 tained from any one female, it did not 

 appear profitable with the time at our 

 disposal to attempt to determine the 

 genotypes of individual females, al- 

 though we realized that this would 

 eventually be a necessary step. 



Methods of Obtaining Data 



All of the evidence used in this 

 study was obtained from the individual 

 registry certificates in the office of the 

 Holstein-Friesian Association at Brat- 

 tleboro, Vermont. These certificates 

 contain among other things the regis- 

 try number of the animal, registry 

 ntimber of sire and dam, and a sketch 

 of the spotting of the animal drawn on 



a standardized diagram. The accuracy 

 of the parentage records of these ani- 

 mals need not l)e questioned since 

 this is a matter of considerable con- 

 cern to the registry office and is 

 checked by them. The sketch of the 

 animal is made by the breeder and al- 

 though checked by an independent ob- 

 server, is admittedly an approxima- 

 tion. It is sometimes rechecked when 

 the animal is sold and a new registry 

 certificate made out ; and in such cases 

 the agreement of the two records 

 is reasonably good. The original 

 sketches are nearly all made from 

 voung animals and some variation 

 from this is to be expected when the 

 same animal is resketched after at- 

 taining full size. The officials of the 



