134 



Testing Milk and Its Products. 



Average results obtained in weighing and testing a cow's milk 

 daily during one period of lactation. 



158. The average test of this cow's milk for her whole 

 period of lactation was 3.8 per cent, of fat (i. e., the total 

 quantity of fat produced -f- total milk yield X 100); twice 

 during this time the milk of the cow tested as high as 

 5.8 per cent., and once as low as 2.7 per cent., while tests 

 of 3.0 and 4.6 per cent, were obtained a number of times. 

 The average weight of milk produced per day by the 

 cow was 14 Ibs. ; this multiplied by her average test, 3.8, 

 shows that she produced on the average .53 Ibs., or about 

 one-half of a pound, of butter fat per day during her lac- 

 tation period. If, however, her butter-producing capac- 

 ity had been judged by the test of her milk for one day 

 only, this test might have been made either on the day 

 when her milk tested 5.8 per cent., or when it was as low 

 as 2. 7 per cent. Both of these tests were made in mid- 

 winter when the cow gave about 16 Ibs. of milk a day. 

 Multiplying this quantity by .058 gives .93 Ibs. of fat, and 

 by .027 gives .43 Ibs. of fat. Either result might show 



