﻿TIlANSMia?TTNG ABILITY OF HOLSTEIN-FBIESIAlSr SIRES 



23 



Of the three sires whose daughters have a distinct correlation with 

 their dams relative to butterfat yield, all have daughters with a 

 greater average yield than their dams, though in the case of the 

 daughters of su-e P this average increase amounts to only 6.4 pounds, 

 whereas the average milk yield of his daughters is somewhat less 

 than that of their dams. The four sires whose daughters show 

 evidence of correlation have daughters with rather a large average 

 increase in both milk and butterfat yield over their dams, excepting 

 in the case of sire R, whose daughters show a decrease in butterfat, 

 owing to a lower percentage of fat in the milk. With sires whose 

 daughters had smaller average yields of butterfat than their dams, 

 the daughters show no correlation at all with their dams with respect 

 to butterfat yield. 



Does the correlation coefficient indicate the relative influence of 

 the parent on the ofi^spring? Does the fact that the daughters of 

 sire P show a correlation of +0.90 to their dams in butterfat yield 

 indicate that the dams had far greater influence on their producing 

 capacity than did sire P? Where there is no significant correlation 

 between daughters and dams, meaning that the size of a daughter's 

 record does not have any particular relation to the size of her dam's 

 record, does this indicate that the sire is exerting greater influence 

 on the producing capacity of the daughters than are the dams? 

 If so, what would a marked negative correlation indicate, a case 

 where the lowest-producing daughters were from the highest- 

 producing dams, and the highest-producing daughters from the 

 lowest-producing dams? The daughters of sire N are the only ones 

 showing any significant negative correlation, though the probable 

 error is so great as to neutralize its significance. The relative rank 

 of the coefficients of correlation of the daughters of each sire to 

 their dams in butterfat yield is shown in Table 11, and in comparison 

 is shown the relative rank among the 23 sires as given in Table 5. 

 The sires are ranked in this table according to the size of the coeflS.- 

 cient of correlation without regard to the significance of the probable 

 It should also be remembered that in ranking the sires in 



error. 



Table 5 milk yield as well as butterfat yield were considered. 



Table 11. — Rank of sires according to coefficient of correlation between daughters 

 and dams with respect to butterfat production, and the comparative ranking of 

 sires as in Table 5 



Sire 



Coeflicient of 



correlation of 



daughters 



to dams 



Rnrk of 

 sirts in 

 Table 5 



Sire 



CoefTioient of 



correlation of 



daughters 



to dams 



Rank of 

 sires in 

 Table 5 



P 



+0.90 ±0.05 

 +0. 71 dbO. 11 

 +0.71 ±0.10 

 +0.67 ±0.15 

 +0.66 ±0.16 

 +0. 60 dbO. 14 

 +0.51 ±f).30 

 +0.48 ±0.21 

 +0.47 ±0.22 

 +0.43 ±0.21 

 +0.:M ±0.13 

 +0.17 ±0.19 



18 







10 

 12 

 20 

 4 



17 

 7 

 9 

 8 



n 



3 



E 



+0.15 ±0.27 

 +0.09 ±0.25 

 +0. 06 ±0. 16 

 +0. 06 ±0. 25 

 -0. 09 ±0. 30 

 -0.15 ±0.20 

 -0.22 ±0.26 

 -0.Z3 ±0.24 

 -0.23 ±0.18 

 -0. 27 ±0. 24 

 —0.39 ±0.19 



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23 



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A 



5 



D 



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14 







M ::. 



16 



il.. 



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22 



I 



B 



2 



Q 



T 



15 



J. . 



N 



13 



C 











