278 EXPERIMENT STATION RECOED, 



of buttermilk was introduced. The flasks were shaken every morning and 

 evening. It was noticed that the calcium citrate in the flasks "to which the 

 buttermilk was added was slowly going into solution, and on the twelfth day 

 no insoluble citrate remained. An examination showed the checks to be sterile, 

 and with the calcium citrate still on the bottom of the flasks as an insoluble 

 powder. 



Further experiments showed that the volatile acid in sour milk was derived 

 from citric acid and proved to be acetic acid. Of several common dairy bacteria 

 tried, Bacterium lactis aerogenes was the only one found to have the power of 

 fermenting citric acid, and this produced two molecules of acetic acid for every 

 one of citric acid. In the process of cheese making the citric acid all disap- 

 pears before the cheese is put in the press. In one cheese examined the milk 

 used contained 0.203 gra. citric acid per 100 cc. ; the whey when drawn con- 

 taind 0.118 gm. ; the first whey from the pi-ess contained none; the curd when 

 the whey was drawn contained a trace; and the curd when put in the press 

 contained no citric acid. 



On the influence of feeds poor in lime upon the lime content of cow's milk, 

 L. Frank (Chcm. Zty., 3J, (1910), A^o. Ill, pp. 97S, 979).— The milk from 10 cows 

 fed hay from sewage meadows which were deficient in lime contained on an 

 average 0.1576 per cent of calcium oxid. The average percentage in milk from 

 cows fed similar rations supplemented by ground chalk was 0.1595. 



Composition of doge's milk, L. S. Dijkstra (Molk. Ztg. IHildesheim], 2^ 

 {1910), No. 79, p. lJf9.'f). — Analysis of the milk of a female house dog 6 days 

 after parturition gave the following percentages : Fat 7.25, protein 6.65, sugar 

 2.85, ash 0.96, water 82.29. A second analysis 14 days later gave the follow- 

 ing: Fat 5.65, protein 6.95, sugar 2.25, ash 1.04, water 84.11. There was less 

 volatile fatty acids and potassium and more phosphorus than in cow's milk. 

 Casein constituted about one-half the nitrogenous constituents. 



Feeding' for milk production, C. H. Eckles (Missouri Sta. Circ. .'/'/, pp. 

 69-S^, figs. 3). — This contains information of a popular nature concerning the 

 feeding of dairy cows. The principal topics treated are turning on pasture in 

 the spring, grain feeding while on pasture, providing for periods of short pas- 

 ture, winter feeding, reasons for feeding balanced rations, home grown bal- 

 anced rations, succulent feeds, the silo, and buying concentrated feeds. 



The cost of producing market milk, J. B. Lindsey {Massachusetts Sta. Rpt. 

 {1909), pt. 2, pp. 27-31).— A resume of the food cost in 1907 and 1908 of the 

 station herd, consisting of grade and pure bred Jersey cows producing 5 per 

 cent milk. 



" The average yield per cow for the 7 cows in 1907 was 5,874.4 lbs., the food 

 cost per cow was $78.19, and the cost of a quart of milk 3 cts. In 1908, the 

 yield per cow in case of 9 cows was 5,639.5 lbs. (2,564 qts.), the food cost per 

 cow $82.21, and the food cost per quart of milk 3.3 cts." 



If other items of cost are added it is believed that the total cost of produc- 

 ing milk satisfactory in sanitary quality and containing from 4 to 5 per cent of 

 butter fat will usually be found to amount to from 4 to 5 cts. per quart. The 

 cost of keeping 1 cow for 1 year is estimated at $137.07. Milk produced under 

 more than average sanitary conditions or certified milk will naturally cost con- 

 siderably more than the figures presented in these estimates. 



The Illinois competitive cow test, C. C. Hayden {Illinois Sta. Circ. IJ/'i. 

 rev., p. 12). — This outlines the plan and rules which govern the state competi- 

 tive cow test. 



Notices of judgment {U. S. Dept. Agr., Notices of Jadginent 628, 629, 632, 638, 

 p. 1 each). — These i-elate to the adulteration of milk. 



