﻿TRAN"SMia?nisrG ability of holstein-feiesiak sires 19 



ing the percentage of fat does not always equal the number of tested 

 daughters given in the first column. The difference represents the 

 number of daughters that had same test as their dams. 



No sire in this list is completely prepotent; that is, no sire has all 

 his tested daughters better than their dams in yield of milk, per- 

 centage of butterfat, and yield of butterfat. Sire E is the only one 

 that increased the milk and butterfat yield of all his tested daughters 

 over the yields of their dams, but only four of his daughters had a 

 higher percentage of butterfat than their da,ms. Several sires in- 

 creased the milk yield of a great majority of their daughters. For 

 example, one sire increased the milk yield of 4 out of 5 daughters; 

 another sire increased the milk yield of 11 out of 13 daughters; 

 another 10 out of 12 daughters; another 9 out of 11 daughters; and 

 another 7 out of 9 daughters. 



Some sires were also prepotent in decreasing the mdlk yield; for 

 example, one sire decreased the milk yield of 5 out of 6 daughters; 

 another, 6 out of 7 daughters; another, 11 out of 16; and another, 

 4 out of 7 daughters. 



Four sires were prepotent in influencing the percentage of butterfat 

 in the milk of their daughters. One sirens daughters had higher 

 percentages of butterfat than their dams in every case. On the 

 other hand, two sires had 6 out of 7 daughters with lower percentages 

 of butterfat than their dams, and another sire had 14 out of 16 daugh- 

 ters with lower percentages. 



Only nine sires had a majority of their daughters with higher 



Eercentages of butterfat than their dams. There were 15 sires that 

 ad over half their daughters with a larger yield of milk than their 

 dams, and 16 sires had over half their daughters with a larger yield 

 of butterfat than their dams. 



This study indicates that some sires are capable of increasing in 

 the great majority of their daughters both the yield of milk and the 

 percentage of butterfat in the milk over that of the dams. Some 

 sires may increase the yield of milk in the majority of their daughters 

 and decrease the percentage of butterfat. Several sires decreased 

 both yield of milk and percentage of butterfat in the milk. Fewer 

 sires were prepotent in increasing the percentage of butterfat in 

 the milk of their daughters than in increasing the milk yield of 

 their daughters. No sire in the list increased both the milk yield 

 and the percentage of butterfat in the milk of all his daughters, or 

 decreased the milk yield and the butterfat percentage in the milk 

 of all his daughters. 



METHOD OF BREEDING AND RECORD OF DAM AS INDICATIONS OF 

 A SIRE'S BREEDING ABILITY 



Table 9 shows the 23 sires listed in the order in which they were 

 ranked on the basis of comparative production of milk and butterfat 

 of their daughters, as in TabJe 7. The record of tlic dam of each 

 sire is given first. The next column shows wlietlier the sire was 

 inbred, line bred, or outbrod; and the last two columns give this 

 same information for his sire and his dam. The figures in the last 

 tluee columns refer to the popular expression "common blood," 

 meaning the percentage of common ancestry that appeared on the 

 sire's and dam's side of the pedigree in five ancestral generations. 



