1917] DAIRY FARMING DAIRYING. 773 



standing third. . . . Alfalfa hay was 12 per cent more economical as a milk- 

 producing roughage than soy-bean hay when both were selling at the same price 

 per ton. This does not take into account the greater quantity of soy-bean hay 

 refused, due to its impalatable characteristic. 



" The cost of milk was affeqted to the greatest degree by varying the price 

 of corn ; the hay was of next importance, the corn silage ranked third, and 

 the protein-carrying concentrates fourth. The hay and corn exerted almost 

 the same influence upon the cost of milk. The use of soy-bean hay "caused an 

 increase in body weight and a decrease in daily milk and butter-fat production. 



" Properly balanced rations are, approximately, equally efficient in the pro- 

 duction of milk and butter fat per unit consumption of dry matter. The nu- 

 tritive ratio of a ration may be varied within reasonable limits without ma- 

 terially affecting the productive power of the ration." 



In the experiment to determine the effect of cotton.seed meal and linseed meal 

 upon the breeding power of dairy heifers (E. S. R., 34, p. 775), 16 heifers fed 

 in winter a ration of wheat bran, corn silage, and alfalfa hay supplemented with 

 3.103 lbs. of cottonseed meal daily were bred an average of 1.06 times each, the 

 average age at time of conception being 1 year, 7 months, and 6 days. Nine- 

 teen heifers fed the same as the above lot, except that 3.055 lbs. of linseed 

 meal replaced the cottonseed meal, were bred an average of 1.8 times each, the 

 average age at conception being 1 year, 7 months, and 26 days. 



In experiments upon the pasteurization of cream for butter making it was 

 found that in the case of sour, gathered cream that is not neutralized pas- 

 teurization at 145° F. for 20 minutes is the most satisfactory process from the 

 standpoint of germ-killing efficiency and quality of butter. 



In studies upon the changes occurring in butter and milk fat during storage 

 it was found that the proteins are gradually hydrolyzed into simpler compounds. 

 During this hydrolysis, amino acids are formed as one of the decomposition 

 products. The degree of hydrolysis depends upon the initial condition of the 

 proteids, the quantity of hydrolizing agents present, and the tempei'ature at 

 which the butter is kept. The percentage of gain in proteid nitrogen not 

 precipitated by phosphotungstic acid was 4.157 for raw cream butter, 3.465 for 

 butter from cream pasteurized at 145° for 20 minutes, 3.161 for butter from 

 cream pasteurized at 165° flash, and 2.99 for butter from cream pasteurized at 

 185° flash. Little variation was found in the constants of the fat of stored 

 butter with the exception of the acid value, which showed a marked increase 

 in the raw cream butter and smaller increases in butters from cream pas- 

 teurized at different temperatures. 



Bacteriological analyses made of the cream and butter in connection with 

 the pasteurization experiment show that pasteurization at 145°, holding process, 

 " gives the greatest killing efficiency for all varieties of micro-organisms pres- 

 ent. The flash system at 185° gives next best killing efficiency but does not 

 give uniform results. The flash system at 165° shows lowest killing efficiency 

 for all varieties of micro-organisms and is the most variable of the three 

 methods." 



Preliminary studies upon the cause of oily flavor in butter from cream pas- 

 teurized at 185° indicate that this condition is due to a combination of the 

 high degree of heat in the presence of high acidity. 



Notes are given on the activities of the department in the testing of pure- 

 bred dairy cows and creamery inspection work. 



Feeding and management of dairy calves and young dairy stock, W. K. 

 Brainerd and H. P. Davis {U. S. Dept. Agr., Farmers' Bui. 777 {1917), pp. 19, 

 figs. 5). — In addition to a detailed discussion of this subject, brief information 

 is given on calf diseases. 



