96 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



operating the plant without creating a nuisance some very satisfac- 

 tory results have been obtained. It has been estimated that the total 

 sewage from the creamery has an oxygen requirement for its reduc- 

 tion equivalent to that of the sewage from a village of 1,200 people. 

 A combination of septic tank and sand filter of proper size has given 

 an effluent which could be run on to the land without danger of 

 offensive odors. 



MARKET MILK INVESTIGATIONS. 



The work in connection with market milk is in charge of Ernest 

 Kelly. 



DAIRY SANITATION. 



Work has been carried on, as heretofore, to promote the sanitary 

 production and handling of milk. Milk surveys of cities are made, 

 assistance is given to State and municipal boards of health in mak- 

 ing regulations for selling milk, and aid is given dairymen in im- 

 proving conditions and methods used in the production of milk. 

 State and municipal health officers have been very appreciative of 

 this work and have cooperated in carrying it on. 



During the year a large number of cities were visited and confer- 

 ences and demonstrations were held. Actual inspection work, com- 

 bined with demonstrations in the presence of local inspectors, has 

 been done for the purpose of improving the city milk supply in 21 

 cities in 17 States. In this work 374 farms and 82 city milk plants 

 were scored, among which were all the certified dairies supplying 

 milk to Chicago. 



Milk contests were held in 11 cities in 9 States, and 951 samples of 

 milk and cream were scored. 



Aside from these demonstrations and inspections, 31 cities in 16 

 States were visited to check up previous work, to hold conferences 

 with local officials, and to attend meetings. 



Some of this work was done during the summer of 1915, in coopera- 

 tion with a field party from the Bureau of Chemistry. That bureau 

 made laboratory examinations of milk shipped in interstate com- 

 merce; a representative of this division then visited the dairies 

 showing high bacterial counts and suggested changes to improve the 

 quality of the milk. 



Milk producers, health officials, milk dealers, and consumers have 

 been brought closer together and a much better understanding has 

 resulted. There is a growing tendency on the part of the dealers to 

 grade milk and to buy and sell on such a basis — a principle strongly 

 advocated by the Dairy Division. 



A practical achievement of the year was the devising of a simple 

 and inexpensive steam sterilizer for use on small dairy farms, 

 through the joint efforts of the market-milk section and the research 

 laboratories of the Dairy Division. This sterilizer, which is de- 

 scribed in Farmers' Bulletin 748, makes it practicable to sterilize 

 dairy utensils on the farm at very low cost. 



Experiments carried on with various strainers for milk indicate 

 that cheesecloth alone is very ineffective. The best results were 

 obtained by using a layer of absorbent cotton between layers of 

 cheesecloth. 



