THE CELLULAR CONTENT OF MILK 143 



higher the number of leucocytes found. Savage also investigated 

 the varieties of leucocytes in the number of the estimations 

 of total cellular content made by him. In definite pathological 

 conditions the number of leucocytes was greatly increased, and 

 there was a tendency for a high leucocyte count to persist in con- 

 ditions of old trouble which was no longer active. This continued 

 high cell count after the subsidency of inflammation has been pointed 

 out by several observers who have investigated the cell content of 

 milk. 1 



Hewlett, in the course of numerous investigations upon the cell 

 content of the milk from a large number of cows, examined the milk 

 from several cows in the later stages of lactation. In three cases no 

 rise of cell content was obtained, and the cows were found to be 

 non-pregnant. In a number of other cases the cell content was 

 found to be high, but no connection could be traced either with 

 the stage of lactation or with any unsatisfactory condition of the 

 udder. 



Ross found no apparent relationship between the cell content 

 and the amount of milk produced or with the fat content. Great 

 variations were found between the different cows and also in the 

 milk of the same cow at different times. As a whole, the cell content 

 was higher in the strippings than in the middle milk, which itself 

 showed a higher cell content than the first milk. This agrees 

 with the findings of Campbell quoted above. Ross believed that 

 as a rule the cell content was higher in colostrum than in later 

 milk, and was greatly increased in any inflammatory condition of 

 the udder. 



Frick investigated the cell content in relation to the reaction 

 of the milk, using TrommsdorfFs method. Colostrum having an 

 increased acidity over normal milk, was associated with a high 

 leucocyte count. The leucocyte count of the later milk of cows 

 depended upon whether the cow was pregnant or not. In the 

 former case Frick obtained a reduced acidity of the milk and a 

 raised leucocyte count. In the case of non-pregnant cows no 

 change in the acidity or the leucocyte count from that of normal 

 milk was found. 



Presence of Disease. There is very general agreement on the 

 part of observers as to the rise in cell content which occurs in 

 mastitis, although all are not agreed that a rise in cell content 

 necessarily denotes mastitis. The results given above show that a 

 high cell content may occur under numerous conditions which are 

 not associated with mastitis. This disease in cows is caused by 

 various bacteria, but in many instances is due to an infection from 

 some form of streptococcus. Hence, if a high cell count is found to 

 be associated with the presence of streptococcus, the suggestion that 

 the two are connected and are diagnostic of mastitis is not an 



1 Cp. Hastings and Hoffmann, Hewlett, Villar and Revis, also Russell 

 and Hoffmann. 



