QUANTITY 



129 



The averages of different breeds show considerable 

 variations : not because all the cows in one breed give 

 milk of one quality while all in other breeds give milk 

 of other qualities, but because some breeds contain a 

 large proportion of cows giving milk of various high 

 qualities, others a large proportion of cows giving milk 

 of various low qualities, and so on. Although some 

 Jerseys' milk contains only 3 per cent, of fat, yet, 

 because the milk of a large number contains from 4*5 

 to 5*5 per cent., the average for the breed is nearly 

 5 per cent. Some Ayrshires give milk containing 5 per 

 cent, of fat, yet, because many give milk containing 

 less than 3*5 per cent., the average for the breed is 

 only about 3*7 per cent. The average for Red Danish 

 cows is still lower ; that for Dutch cows lowest not 

 only on the average but also in both extremes. The 

 following table shows the variations in these three last 

 breeds, which as yet are the only ones from which 

 reliable data have been obtained in large quantity : 



Percentage of Cows giving Different 



Qualities of Milk 



I 



Percentage 

 of Fat 

 in Milk 



3 

 4 

 5 



6 



7 

 8 

 9 

 



