DAIRY FARMING DAIRYING. 687 



Ropiness in milk and cream, A. R. Ward {Dairy and Produce Rev., 1 {J903), 

 No. 30, ])]). S, 9). — Thi.s is essentially the article noted above. 



A bacteriological study of the college creamery milk supply, C. H. Eckles 

 {louaSta. Bui. 59, jrp. 37-49). — Samples of the mixed milk supplied to the college 

 creamery were taken once a week during one year and subjected to fermentation 

 tests and bacteriological examinations. The results are tabulated and discussed, and 

 summarized as follows: 



"The fermentation test shows when milk is in suitable condition for making good 

 butter and {;heese. 



"This test applied to the milk from the patrons of the college creamery shows a 

 great variation in quality during a year. 



"This difference in fermentations is probably due to the conditions under which 

 milk is handled during the different seasons of the year. 



"The average quality of butter made under natural conditions corresponds with 

 the quality of milk as shown by these tests and is dependent upon the condition of 

 the milk. The i)rincipal reason for the fine quality of butter made in the summer 

 and the poorer (juality in winter is this difference in the fermentations in the milk. 



"The number of bacteria found in milk as brought to the creamery varies with 

 the temperature, season of the year, etc. In the winter on an average each cubic 

 centimeter contains from 1,000,000 to 5,000,000. In the summer from 15,000,000 to 

 30,000,000, although these limits may be passed either way. The few bacteria found 

 in milk during the winter makes it possible to control the fermentation to a large 

 extent by the use of starters. 



' ' The acid-producing bacteria are always present in quite large numbers and make 

 up from 25 to 85 per cent and average for the year about 58 per cent of the total num- 

 ber. This class is present in smallest numbers when the quality of the milk is the 

 poorest and in greatest numbers when the milk is the best. 



"The class of bacteria (enzym producing) which coagulate milk sweet or dissolve 

 the curd contains most of those injurious to butter making. They are present at all 

 times of the year, but in far greater proportion when the milk is of the poorest 

 quality. 



' ' Bacteria having no visible effect on milk are always present in large numbers and 

 make up from 20 to 55 per cent of the entire number. 



"Gelatin liquefiers are almost always present in milk, and in the largest numbers 

 in milk of a poor quality, especially during the winter months. 



"Gas-producing germs belong mostly to the Bi trier hua ierogenes type and are found 

 in milk at all seasons, but in far greater number during the hottest weather of 

 summer. 



"Milk brought to a factory once in 2 days is not necessarily injured in quality for 

 butter making, and this can not be considered as the chief cause of liad milk and poor 

 butter in winter." 



The source of milk supply for towns and cities, A. AV. Bitting {Indiana Sta. 

 Bui. 6'9, 2)p, 39~':9). — In a study of the milk supply of the city of Lafayette, Ind., 

 covering one year, the author tested some 700 samples of milk and inspected the 

 various dairy farms in the vicinity. Tlie results of the study are embodied in a 

 general di.scussion of the production and delivery of milk in cities and descriptions 

 of 29 of the dairies furnishing milk to Lafayette. Topics considered in the discussion 

 include the food value of milk, bacteria in milk, dairy herds, stables, food, water 

 supply, milking, and the cooling and <lelivery of milk. In comparing methods of 

 delivery it was found that the fat content of the milk delivered by drawing from the 

 bottom of the can varied from 1 to 4.4 per cent, while that delivered by dipping 

 remained uniform at 3.(5 per cent. The number of cows in the different herds 

 described varied from 4 to 70 and averaged about 21. The fat content of the milk 

 as determined by from 1 to 9 tests in each case ranged from about 3.1 to 4.3 per cent, 

 and averaged about 3.7 per cent. 



