DAIRY FARMING DAIRYING. 



483 



Since the number of cows calving was about the same during the 

 different months of the year, the changes found in the fat content of 

 the herd milk can not be due to inequality in numbers, and it is seen 

 that but slight variations occur in the average quality of the milk of 

 cows that drop their calves in different months of the year. 



The milk of cows that milked longer than 11 months was found to 

 contain, on the average, between 8.6 and 3.8 per cent of fat. 



No decided effect of age on the quality of milk was found, there 

 being an extreme difference of less than 0.1 percent in the average 

 fat content of milk from cows from 3 to 13 years old; data for about 

 60 cows were included in each of the groups for the different years. 



The author concludes that the data obtained furnish evidence as to 

 the influence of heredity on the quality of the milk. Tables are given 

 showing the average fat content of the milk of dams and their daugh- 

 ters for each of 5 sires used, a summary of which follows: 



Increase or decrease in the average fat content of cows' milk as compared with that of their 



dams' milk. 



a Number of daughters included. 



Three of the bulls caused a marked improvement in the quality of 

 the milk produced by their offspring, while in case of one bull 

 (McDonald 628) there was an improvement in 7 cases and a deteriora- 

 tion in 5 cases (on the average an increase of 0.09 per cent), and Dash 

 2d 660 in all cases had daughters that gave poorer milk than their 

 dams. This bull was out of a cow, GuUros 2d 551, that produced milk 

 of a poor quality, the average percentage of fat in her milk being 

 3.06. In general the greatest improvement was observed in case of 

 cows producing the poorest grades of milk. The data so far secured 

 on this point are not considered sufficient to permit of definite con- 

 clusions as to the relative influence of the ancestors of a cow on the 

 quality of milk produced by her, l)ut they show, at any rate, that the 

 bull exerts a decided influence for better or worse on the milk product 

 of his progeny. — f. w. woll. 



