52 Report of the Department <>k Bacteriology of the 



of general surveys of the situation. While these general surveys 

 were a necessary preliminary they gave little information as to either 

 the absolute or the relative importance of any given dairy operation. 



Later these official dairy regulations took the form of score cards. 1 

 These cards not only selected certain operations as important but 

 assigned to each of them a definite numerical value. 



This arbitrary selection of values in the absence of definite infor- 

 mation upon the subject has frequently done injustice to the dairy 

 business and can be justified only upon the ground of the urgent need 

 of official action. The importance of the interests involved demands 

 that the needed information shall be furnished as promptly as 

 possible. 



Investigations directed toward this end have been in progress at 

 this Station for some years. The results of studies of milking 

 machines, 2 of small-topped milking pails, 3 and of the germ content of 

 the udders 4 have already been presented and the studies of the 

 influence of barn air upon the germ content of the milk are in progress. 



The present publication summarizes observations made upon the 

 influence upon the milk of such operations as protecting the milk 

 pails, plastering and otherwise renovating the interior of the cow 

 stable, clipping the cows' udders and flanks and cleaning the cows by 

 hand and with the vacuum cleaner. It chances that some of these 

 operations have been found to have little or no influence upon the 

 milk but because of the previous lack of exact information these 

 measurements are none the less important on this account. If the 

 dairy work of the future is to be done with the highest efficiency and 

 at the least expense it is very important to recognize that a few opera- 

 tions do and that many do not effect the sanitary quality of the milk. 



The accumulation of the data here recorded has extended over a 

 period of about five years. In the experiments conducted up to 

 August, 1910, the collection of the samples and their analysis and the 

 keeping of the notes were entrusted to Mr. Wilson. This includes 

 all the data presented under the headings, " Results of protecting 



1 One of the earliest dairy score cards, if not the earliest, is given ia the Annual Report of the 

 Health Officer of the District of Columbia, 25 (1903-4): 27. 1904. 



2 Harding, H. A., Wilson, J. K., and Smith, G. A. Milking Machines: Effect of method of 

 handling on the germ content of the milk. N. Y. Agr. Exp. Station Brl. 317. 1909. Also in 

 Smith, G. A., and Harding, H. A. Milking Machines: Effect of machine method of milking upon 

 the milk flow. N. Y. Agr. Exp. Station Bui. 353. 1912. 



3 Harding, H. A., Wilson, J. K., and Smith, G. A. The modern milk pail. N. Y. Agr. Exp. Station 

 Bui. 326. 1910. 



« Harding, H. A., and Wilson, J. K. A study of the udder flora of cows. N. Y. Agr. Exp. Sta- 

 tion Technical Bui. 27. 1913. 



