Testing Milk on the Farm. 



145 



Average results obtained in weighing and testing a cow's 

 milk daily during one period of lactation. 



162. 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. 

 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 lb., or 

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

 her lactation period. If, however, her butter-producing 

 capacity 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 

 lb. of fat, and by .027 gives .43 lb. of fat. Either 

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