54 THE NORMAL COMPOSITION OF MILK 



leucocytes are present and also, during the first few days, large 

 numbers of erythrocytes. 



The composition of colostrum is shown in Tables XXX and 

 XXXI. 



According to Jensen the amylase and catalase content is 

 increased during the colostral period but reductase is absent. 



Abnormal and Adultebated Milk 



Influence of Disease. Although the chemical examination 

 of milk produced under pathological conditions is of but httle, 

 practical importance owing to the infrequency with which such 

 conditions exist and the improbability of this milk being sold 

 immixed with normal milk, it is, nevertheless, of interest to 

 consider the general changes that occur. Acute diseases asso- 

 ciated with great pain and fever are usually characterised by a 

 rapid diminution in the quantity of milk secreted. In general 

 and specific infections the fat may be either increased or de- 

 creased with similar fluctuations in the ash and lactose contents. 

 According to Schnorf , most of the internal infections, even when 

 the udder is not involved, produce a diminution in the lactose 

 and proteid content as a result of increased metaboUsm. Cata- 

 lase, especially in peritonitis and tuberculosis, may be consid- 

 erably increased and changes in taste and coagulabiUty may 

 result from general infections. 



Although it is well known that the composition of milk 

 changes with alterations in the function and condition of the 

 secreting organs, comparatively little is known regarding the 

 influence of diseases of the udder upon the various constituents 

 of the milk. Many analyses have been made and various ob- 

 servers have obtained what are apparently discordant results, 

 but this may be attributed to factors such as intensity and 

 duration of the disease being different. 



In acute forms of mastitis, caused by organisms of the colon 

 group, or streptococci, or in mixed infections, the milk may 

 have a bloody discolouration, later becoming more like colos- 



