72 



MANUAL OF MILK PRODUCTS 



FIG. 3. Relative size of fat globules in milk. Upper, as influenced by 

 breed. Lower, as influenced by stage of lactation. (1) First 4-week period; 

 (2) fifth 4-week period ; (3) ninth 4-week period ; (4) thirteenth 4-week period. 



Influence of age of cows on number and size of fat globules. 



Woll l studied the milk of twelve cows to determine the effect 

 of age on the number and size of the fat globules. His work 

 covered a period of three years, samples being taken at the be- 

 ginning and end of the lactation period. The following table 

 gives the data thus obtained : 



EFFECT OF AGE OF Cows ON FAT GLOBULES IN MILK 



AT BEGINNING OF LACTATION PERIOD 

 THREE-YEAR SERIES 



AT END OF LACTATION PERIOD 

 THREE-YEAR SERIES 



1 Wis. Report, 1894, pp. 237-238. 



