206 



Variations in Milk. 



[JULY, 



not only as a means of determining which are the unprofitable 

 animals in his herd, but also with the object of assuring him 

 that the milk which he is supplying to the public conforms 

 in quality with the Sale of Milk Regulations. (See Leaflet 

 No 146 and Journal, May, 1907, p. 88.) 



To assist those who are not in a position to carry out the 

 necessary tests for themselves, the Board of Agriculture 

 have made arrangements with the various Agricultural Colleges 

 in different parts of the country, whereby the farmer can have 

 the percentage of fat in his milk determined at the nominal 

 fee of 6d. per sample. This scheme has now been in operation 

 for nearly two years, and has been taken advantage of to a 

 considerable extent (see Journal, June, 1907, p. 177). In the 

 case of large herds of cows, however, if this work is to be 

 really effective, it must be done by the large dairy farmers 

 themselves, and it is not difficult to prove that the accurate 

 information obtained in this way will amply compensate them 

 for the trouble and expense involved in systematic testing. 



When we consider the average composition of milk, it may 

 be pointed out that if the number of samples examined is 

 large the average composition is wonderfully constant. In a 

 paper recently read before the Society of Public Analysts 

 (Droop Richmond, Analyst, XXXI, 1906, 176), the results 

 w r ere given of the analyses made during the year 1905 of 31,120 

 samples of milk from the South of England. The average 

 composition was as follows : — 



Percentage Percentage 

 of Fat. of Total Solids. 



Morning Milk 3*54 ... 12*53 



Evening ., ... ... ... 3*91 ... I2"86 



These figures are practically the same as the average figures 

 found in the previous year, the fat differing by only *oi per cent. 



An enquiry into the composition of milk must show, however, 

 not only the average composition of the milk, but also the 

 limits within which variation usually takes place. The 

 further question is also raised as to how far the average 

 composition is the same in different parts of the country, 

 and to what extent the composition and the limits of variation 

 are affected by the different breeds of cattle employed, and 

 the different climatic, conditions which obtain there. Both 

 these questions were discussed at the Departmental enquiry 



