DAIEY FARMING — DAIRYING. 183 



and during the other 6 months of the year, when silage was fed, the average yield 

 was 3,050 lbs. of milk and 156 lbs. of butter. The use of nitrate of soda at the rate 

 of 150 to 160 lbs. per acre was found to be profitable in the case of rye, wheat, and 

 barnyard millet, and slightly unprofital)le in the case of barley sown very late in the 

 season. Liming proved beneficial in all the tests made. 



Data concerning the fertilizing elements contained in the feeding stuffs purchased 

 and in the milk produced by the dairy herd showed a decided gain to the farm dur- 

 ing the 6 years in which dairying in relation to soil exhaustion has been studied. 



Four cases of milk fever, with 3 recoveries following the Schmidt treatment, are 

 reported. 



The average cost of milk production for 6 years was 2.39 cts. per quart, which 

 includes food, labor, and interest on and decrease in the value of the herd. 



A monthly record of 22 cows for the year ended April 1, 1902, is given. The 

 average yield of milk per cow was 6,671.1 lbs. and the average fat content of the 

 milk was 4.22 per cent. The waste in handling and delivering milk during the year 

 was 2 per cent, as compared with 10.8 per cent in 1897. 



Dairy herd records, J. H. [Grisdale and R. Robertson {Canada Expt. Farms 

 Upts. IDOJ, pp. 63-72, 252, 253). — Records for one year are given of 26 cows at the 

 Central Experimental Farm and 22 cows at the Experimental Farm for the Maritime 

 Provinces. 



Tests of pure-bred cows, J. B. Lindsey { Massaclimeits Sla. Bpt. 1902, })p. 57-60). — 

 Seven-day tests of 10 Jersey cows are reported. Of the 133.38 lbs. of fat produced 

 by the 10 cows, 128.59 lbs., or 96.41 percent, was recovered in the manufactured but- 

 ter. Analyses of 16 samples of the butter showed the following average composition: 

 Water 14.03 per cent, fat 82.88 per cent, salt 2.45 per cent, curd 0.74 per cent. 



Milking- experiments, J. H. Grisdale {Canada E.vpt. Farms Rj^ts. 1902, jj. 70). — 

 Four ex])eriments to determine the effect upon the yield and quality of milk of milk- 

 ing cows at unequal intervals are briefly summarized. The results are considered as 

 indicating that — 



" (1) Slight inequalities in the intervals between milkings do not affect the average 

 percentage of fat in the daily yield of milk, nor the average daily yield of milk. 



" (2) N'ery considerable inequalities in the intervals between milkings would appear 

 to affect slightly both the quantity and quality of the milk produced, the quantity 

 Ijeing reduced and the quality somewhat inferior. The amount of butter fat in 100 

 lbs. of milk seemed to be reduced by about 3^ per cent. 



" (3) Very considerable inequalities in the intervals between milkings affected the 

 amount of milk and the percentage of fat in the milk at the different milkings. The 

 amount of milk after the long interval was much greater than that yielded after the 

 short interval, but the jiercentage of butter fat in the milk after the long period was 

 much lower than the percentage of fat in the milk after the short interval. 



" (4) On the whole, it would appear that inequalities in the intervals between milk- 

 ings need arouse no anxiety as to their effect upon the quantity or quality of the prod- 

 uct, provided no considerable sudden changes are made." 



The bacterial contamination of milk, F. C. Harrison {Rev. Ghi. Laii, 2 {1903), 

 Nos. 20, pp. 457-463; 21, pp. 481-4^9; 22, pp. 510-519; 23, pp. 538-546).— The author 

 discusses the infection of milk by bacteria contained in the udder and contamination 

 from the exterior of the animal, from the milker, from the air of the stable, and from 

 dairy utensils, reviewing consideral)le literature to which references are appended, 

 and reporting briefly the results of experiments conducted by himself. The experi- 

 ments relating to the bacterial flora of freshly drawn milk have been noted from 

 another source (E. S. R., 14, p. 907). 



In the author's experience the use of a milking machine greatly increased the bac- 

 terial content of the milk. The purification of milk by centrifugal separation was 

 investigated. The bacterial content of the cream and skim milk mixed after separa- 

 tion was greater than that of the milk before separation in 24 out of 30 experiments. 



