158 Maine Agricultural Experiment Station. 1919. 



grees. Thus Ida's Stoke Pogis 15658, Golden Lad 1242, Gold- 

 en Fern 471 1, Sultana's Rosette 2881, Oonan 1485, Ida of St. 

 Lambert 24990 and Oonan's Pogis 17165 appear more often 

 in the pedigrees of the sires who increase the production of 

 their progeny than they do in the pedigrees of the sires whose 

 progeny performed poorly. 



From this pedigree analysis certain conclusions may be 

 drawn as to the value of pedigree study in determining the 

 worth of a Jersey sire. It is clear that animals, like Golden 

 Lad 1242, may occur in the pedigree of sires of inferior merit 

 as well as in the pedigree of sires of real worth. 



The instances of this are not rare for as may be seen from 

 the two tables practically every animal which appears in the 

 one group of the pedigrees also appears in the pedigrees of the 

 other group. These facts make it clear that the only true test 

 of an animal's worth is the performance of his progeny. It is 

 also clear that the study of the pedigree as ordinarily made by 

 the breeder has very little real significance. This performance 

 test may as in this study be entirely devoid of any hypothesis 

 or preconceived notion of inheritance or the worth of any in- 

 dividual animal. 



Summary 



This paper has as its objective a "Progeny Performance" 

 analysis of the American Jersey Registry of Merit Sires, to 

 ascertain the nature of their transmitting qualities for milk 

 production, butter-fat percentage and butter-fat, the whole to 

 be put in concrete, easily understandable, numerical terms. For 

 this purpose we define the sire which causes his daughters to 

 be better producers, whether it be in quantity or quality of their 

 milk, than their dams, as sires superior in their transmitting 

 qualities, for either or both of these variables and the sires as 

 inferior in their transmitting qualities for quantity or quality 

 of milk when their daughters are poorer producers than their 

 dams. The numerical measure for these transmitting qualities 

 of a given sire is the difference between his daughters and their 

 dam's milk production, butter-fat percentage and butter-fat as 

 the case may be. The plus sign indicates the sire of superior 

 transmitting qualities; the minus sign the sire of inferior trans- 



