28 MILK HYGIENE 



mountainous regions give a richer milk, while breeds 

 from the lowlands yield milk poorer in fat. There are, 

 it is true, exceptions to this rule, e.g., the Allgauer and 

 the brown Swiss cattle give rather a poor milk, while 

 the Devons and the Normandy cattle give milk rich in 

 fat. As an example of breeds that give milk especially 

 rich in fat we may mention the Jerseys and the Gruern- 

 seys, whose milk contains an average of 4.5 per cent, 

 to 5.5 per cent, fat, also the Harz cattle, whose milk is 

 reported to contain an average of 5.8 per cent. fat. On 

 the other hand, milk of the Swiss cows has only 3.0 

 per cent, fat, that of the Angler and Breitenburger and 

 other breeds only about 3.13 per cent, to 3.15 per cent, 

 fat. The average of the Danish breeds can hardly be 

 placed higher, being about 3.2 per cent, to 3.4 per cent, 

 fat. 



2. Individual peculiarities. The figures given above 

 are averages only. The mUk of different individuals 

 varies more or less so that in the same breed there are 

 individuals that give milk rich in fat, and also those 

 whose milk has a percentage of fat below the average 

 of the breed in question. The production of rich milk is, 

 therefore, a distinctly individual property that is due 

 to the physiological peculiarities of the gland cells of the 

 animal, and which appears, to a great degree, to be 

 hereditary. Among cows of the same breed may be found 

 some whose milk contains 4.0 per cent, or more of fat 

 and, on the other hand, there are many that give milk 

 containing only about 2.5 per cent, fat ; indeed, not infre- 

 quently the percentage of fat is still lower, and from 

 Germany there are records of cows that give mUk con- 

 taining not more than 1.5 per cent, of fat. Such cows 

 are frequently and in large numbers excluded from the 

 best herds, so when herds are made up of purchased 

 cows, the mixed milk from such cattle often contains but 



