156 SCIENCE AND PRACTICE OF CHEESE-MAKING 



AMOUNT OF FAT IN MILK 



The percentage of fat in normal milk varies 

 greatly, much more than any other constituent, 

 especially if we consider single milkings of individ- 

 ual cows. In connection with the manufacture of 

 cheese, we are more particularly interested in 

 knowing the percentage of fat in the milk of dif- 

 ferent herds of cows rather than in that of single indi- 

 viduals. In the case of single herds of cows, such 

 as are common in the dairy region of New York 

 state, the lowest percentage of fat found on any 

 one day, as the result of special investigations, 

 was 2.90; the highest, 5.50, which occurred late in 

 the season (October). Taking the average of dif- 

 ferent herds of cows for an entire cheese-factory 

 season (April to November), the lowest percentage 

 of fat was 3.31 and the highest, 4.31. In the case 

 of cheese-factory milk, consisting of a mixture of 

 the milk of different herds, the lowest percentage 

 of fat found was 3.04 and the highest, 4.60. The 

 average percentage of fat in mixed factory milk 

 for an entire season is about 3.75 ; and this average 

 has been found to vary only slightly in different 

 factories and in different seasons. The Wisconsin 

 experiment station reports 3.64 as the season's 

 average percentage of fat in the milk of 347 fac- 

 tories. In the case of individual factories, a sea- 

 son's average as low as 3.20 per cent is given. The 

 lowest percentage of fat in the milk of any single 

 herd for a single day's milk is given as 2.30, while 

 the highest reported is 5. Results reported in Can- 

 ada appear to indicate a lower percentage of fat in 

 milk than in the case of New York. 



