1908.] 



PUBLIC DOCUMENT— No. 3< 



105 



ist determines only the total solids and fat, and obtains the 

 solids not fat by difference. The former two serve as an index 

 of the chemical composition of the milk. 



Composition of Milk of Pure-bred Cows. 

 The following data have been tabulated from authentic 

 sources, in the hope that they will throw light on the composi- 

 tion of milk produced by distinct breeds of dairy cows : — 



(a) American Data. 



1. Jerseys. 



2. Guernsey. 



Eolsteins. 



6 months, 

 4 months, 



Generally 7 



days. 

 One lactation 



period. 

 Eight months, 



Pan-American Exposition at 

 Buffalo.2 



Louisiana Purchase Exposi- 

 tion, St. Louis. 1 



Wisconsin Experiment Sta- 

 tion. <s 



New York Experiment Sta- 

 tion^ 



New Jersey Experiment sta- 

 tion.'' 

 Average, 94 cows, . 



i The Dairy Cow Demonstration, published by American Jersey Cattle Club, 1905, pp. 

 05 and 71. See also Hoard's Dairyman, Nov. 24, 1893, p. 638. This paper gives 13.71 as the 

 total solids for Jerseys. 



2 DeWitt Goodrich, Official Milk Tester (in Creamery Patrons' Handbook, p. 100). 



3 Tenth report, p. 141. 



* Report for 1890, p. 223. 



5 Furnished by W. II. Caldwell, secretary, American Guernsey Cattle Club. Hoard's 

 Dairyman gives 13.41 per cent, solids and 1.51 per cent, fat for Guernseys. 



6 Twentieth report, p. 158. 



