210 Maine Agricultural Experiment Station. 1918. 



have at least 7 daughters in the advanced registry which also 

 have the dams of these daughters recorded. 



The results of this comparison shows that Imp. Mashers 

 Galore 8572 raised the milk production of his daughters 2674 

 pounds over that of the milk production of their dams. The 

 same bull lowered the test of the milk of his daughters 0.196 

 per cent and made a net gain of 116 pounds of butter fat for 

 each of his daughters over that of their dams. This bull quite 

 evidently improved the breed. 



The question often comes up, "What bull am I going to 

 buy?" This table enables us to answer the question in so far 

 as the worth of the bull's hereditary qualities to raise or lower 

 the milk production of his daughters over that of the cows to 

 which he is mated, is concerned. An example will make this 

 clear. The bulls Glenwood Boy of Haddon and Imp. Governor 

 I of the Chene are offered for sale, "Which shall I choose to 

 head my herd?" A glance at the table shows us that Glenwood 

 Boy of Haddon caused his daughters to produce 431 pounds of 

 milk over that of their dams; lowered the fat per cent of these 

 daughters on an average 0.638 per cent; and caused a reduction 

 of 39 pounds of butter-fat for the expected year's record. Imp. 

 Governor 1 of the Chene lowered the production of his daugh- 

 ters 395 pounds of milk; raised the fat per cent of this milk 

 0.248 per cent; and caused a net increase of 17 pounds of butter- 

 fat. These facts justify us in choosing Glenwood Boy of Had- 

 don to head our herd if milk production is sought. If a high 

 testing milk producing a larger quantity of butter-fat is desired 

 the purchase of Imp. Governor 1 of the Chene is justified. 



Variations and Mode of Secretion of Milk Solids 



As previously pointed out the study of existing milk records 

 has been actively pushed. These studies on Holstein-Friesian 

 cattle have been gathered together in a paper the contents of 

 which may be briefly summarized. The average annual milk 

 production of these cows was 15417 pounds, containing 528 

 pounds of butter-fat and 1303 pounds of casein, milk sugar, 

 and ash together with other constituents of less amounts gen- 



