i06 Scientific Proceedings, Royal Dublin Society. 



The above results come out according to the Meudeliau formula, excepting 

 that, although tliere a few third-grade dams there are no third grade 

 daugliters. The reason is tluit, in the herd-book from which these data 

 have been taken tliere are very few third-grade cows entered which were 

 born subsequent to liSSO. These liave been eliminated for breeding purposes 

 by the best Danish breeders since about that time. Consequently, while we 

 can say, from the yields of the dams and their daughters above, even though 

 their numbers are small, that there are certainly first and second class red 

 Danish bulls (for instance, Tordenskjold is probably first class, and Trym i. 

 second), we can identify none that is third class. 



At home we are little better off, since the best breeders usually get rid of 

 their poor milkers as heifers after tlieir first calf. Consequeiitl}', sucli records 

 as would be got from the daughters of a third-class bull are few and incom- 

 plete. To overcome this lack of the ordinary data, however, we can fall 

 back upon the observation made earlier in the paper, that a cow's daily yield 

 at her maximum is an approximate indication of lier total yield for a normal 

 year. By so doing we can get more cases, since we catch poor heifers just 

 after calving, or, at any rate, before they are got rid of. The method may 

 not be absolutely reliable for some other purposes, but it is sufiiciGnt for the 

 present, which is to determine whether sixes fall into three grades like the 

 cows, and breed accordingly. The difilculty in using the method is to 

 detenuine exactly wliere the one grade of cow stops, and the other begins. 

 There is this advantage, however, that there is no danger of putting a tliird- 

 grade cow into the first, or a first into the third. Consequently, any errors in 

 classification can have no vital effect on the general result. If, in herds 

 containiug all three grades of cows, we find bulls liaviug only first- and 

 second-grade daughters, others only second and third, and others all three 

 grades, then we have identified all three grades of bulls. The case is parallel 

 to that of the shorthorn colours. A red bull in a mixed herd of cows gets 

 only red and roan calves ; a white bull gets only roans and whites, and a 

 roan bull gets all three colour's. 



In the following tables the progeny of five bulls used in the same herd 

 of mixed cows are shown. It will be seen that there are all three grades 

 among the five. Other cases have been found, but the numbers of progeny 

 are smaller, and thej' need not be quoted. It should be noted that the herd 

 in which these cases were found is not over-highly fed, and the pastui-e is 

 moderate. Consequently, every grade is slightly lower in yield than the 

 Danish cows were. 



