Animal Husbandry Investigations in 1919. 275 



The records for the sires Taurus Creamelle Hengerveld 

 and Lakeland's Poet are obtained as follows. The records of 

 all daughters of these sires from dams of their own breeding 

 are obtained in similar manner to that described for the cross- 

 bred females. These records showing the milk production of 

 each daughter of a given sire are then summed and the mean 

 taken. This mean is used as the sire's potential transmitting 

 ability. The measure used is consequently the progeny per- 

 formance test for the hereditary composition of the sire for 

 milk production. 



The composition for milk production transmission of the 

 bulls, Delva's University De Kol and Kayan, where no pure 

 offspring are available is determined as follows. For Delva's 

 University De Kol, Taurus Creamelle Hengerveld's test is used 

 since they are bulls of the same breed. Kayan's milk producing 

 capacity is taken as that of the pure bred Aberdeen Angus in 

 the herd. 



Figure 27 shows the milk record on a monthly basis of 

 Crossbred Number 1 corrected to the two year basis. This 

 record is shown as the solid line . The mating to pro- 

 duce this crossbred was a Jersey bull, Lakeland's Poet 102603, 

 bred to a Holstein-Friesian cow, Pauline Posch 81048. The 

 milk production on a monthly basis corrected to the 2 year age 



expectation is given as the dotted line . The expected 



potential milk production of the Jersey sire is given as a dot 



and dash line . The milk production of the 



crossbred clearly follows that for the sire's expectation. The 

 milk production of the Holstein-Friesian dam follow a course 

 much higher than does that of the crossbred daughter. The 

 daughter may therefore be said to have only the inheritance 

 of the low milk producing breed. In view of what follows in 

 these curves this result is somewhat surprising. The result 

 cannot, however, be a mistake for three reasons. The cross- 

 bred daughter's milk production is based on four lactations. 

 The milk production of the Holstein-Friesian dam is based on 

 11 lactations. It is further interesting to note in this connection 

 that Crossbred No. 45 now beginning her lactation, a cross using 

 the same dam but an Aberdeen Angus sire is also milking lower 

 than would be expected. It seems therefore in view of these 

 facts that there is something in this cow's transmitting ability 



