10 DAIRY CHEMISTRY 



While the difference in percentage composition of 

 the milk is .8 of a per cent of fat in favor of cow 

 No. 1, the total yield of fat for three days is .1 of 

 % pound in favor of cow No. 2. Cow No. 2, how- 

 ever, produced a larger amount of milk solids in the 

 form of fat than cow No. 1. In general it is to 

 be noted that whenever a cow produces a pound 

 of butter fat, she also produces about 1.1 of milk 

 sugar, about a pound of casein and albumin, and 

 about .15 of a pound of ash. When milk is paid for 

 on the basis of its fat content for butter making 

 purposes, the total pounds of fat are obtained by 

 multiplying the weight of the milk by its per cent 

 of fat, as 287 pounds of milk testing 3.6 per cent 

 fat contain (287 x .036) 10.33 pounds of fat. In 

 dairy operations all comparisons and calculations 

 are made on the basis of the total fat. 



11. First or Fore Milk and Strippings. — As is 

 well known, the first portion of milk given by any 

 cow at a milking is poor in fat, while the last 

 portion, or strippings, is very rich in fat. The 

 per centage amounts of casein, ash, and sugar, and 

 other ingredients, however, remain nearly constant. 

 The difference in fat content between the first or 

 fore milk and the strippings suggests the impor- 

 tance of careful and exhaustive milking, and also 

 thorough mixing of the milk before taking a sample 

 for analysis. The composition of the first pint and 

 the last pint of milk from two cows is given as an 

 illustration. 



