674 EXPERIMENT STATION EECOED. 



" The dairymen must keep yearly records of their individual cows, discard 

 the poor ones and raise the heifer calves from the best cows by a pure-bred 

 sire. Records for short periods are inconclusive." 



The university dairy herd; management and records, 1907-8, G. O. Hum- 

 phrey and F. W. Woll (Wisconsin Sta. Bui. 167, pp. 3-27, pis. 2, figs. 5).— 

 Methods of feeding and management of the university herd are described and 

 the herd records for the year ending May 13, 1908, are tabulated and discussed 

 as in previous years (E. S. R., 20, p. 77). 



The herd consists of 8 Jerseys, 8 Guernseys (2 grades), 8 Holsteins, 4 Ayr- 

 shires, and 2 Brown Swiss. The cow making the largest profit produced 13,186.2 

 lbs. milk, with an average fat content of 3.62 per cent, equivalent to 477.96 

 lbs. butter fat. The product is valued at $140.59, and the feed cost $45.28. For 

 the past 5 years the herd averaged 7,246.1 lbs. milk per cow per year, contain- 

 ing 4.23 per cent of fat, equivalent to 306.16 lbs. butter fat. The average cost 

 of feed was $37.03, and the average value of the product $81.69. The live 

 weight of the cows, amounts of feed eaten, and analyses of the feeding stuffs 

 are given. 



Concerning' the changes of the bacterial flora of fresh, milk during the 

 so-called incubation period, A. Wolff (Centbl. Bakt. [etc.], 2. AM. 20 (1908), 

 ISIos. 18-20, pp. 5J,5-563; 21-23. pp. 651-675; 2',-25, pp. 737-780; ahs. in Milchw. 

 Zentbl., 4 (1908), No. 7, pp. 314-320). — A study was made of the bacterial 

 content of milk from the time of milking until the coagulation period. The 

 milk from one stable was run through a strainer and collected in a covered 

 tin vessel, and that from another stable was run over a cooler into tin cans at 

 a temperature of 15° to 16° C. Extended tables show the bacterial content of 

 milk when kept at different temperatures. 



The bacterial flora was divided into six groups, as follows: (1) Cocci; (2) 

 lactic acid forms; (3) short-rod forms not belonging to the coli group, (a) the 

 alkali-producing nonliquefying, (b) the other nonliquefying, (c) liquefying, 

 (d) those unaffected by pasteurizing; (4) coli-aerogenes group; (5) spore- 

 forming, (a) aerobic, (b) facultative anaerobic, (c) obligate anaerobic; (6) 

 miscellaneous. The behavior of the different forms grown as pure cultures is 

 described. Two new species of coccus were discovered, which the author calls 

 Sarcina niobilis A. and 8. mobilis B. 



In milk kept at 5° to 7° C. all kinds of bacteria increased for 3 days, espec- 

 ially the cocci and the alkali-producing rods. At 20° all kinds increased faster 

 than at the lower temperatures. The first 3 hours lactic-acid forms were 

 not much in evidence, but after that they made a proportionally larger gain 

 than the others and soon composed over 90 per cent of the flora. At 30° the 

 lactic-acid forms gained still more rapidly and in a few hours were the only 

 kinds present except a few alkali-producing forms. At 37° the lactic-acid 

 forms also increased, likewise the gas-forming coli group. I^actic-acid forms 

 were more numerous in the milk that was run over the cooler than that strained 

 into the covered vessel. They do not grow rapidly at the low temperatures 

 but at the higher temperatures develop so rapidly as to be harmful to many 

 other kinds. 



In milk passed over the cooler Bacterium gilntheri was more abundant than 

 streptococcus at first, but when kept at 5 to 7° the latter increased much the 

 faster. At higher temperatures B. gilntheri increased as a rule faster than 

 streptococcus, and in raw milk in some temperatures it increases so fast that 

 eventually it checks itself. Although it has generally been supposed that B. 

 giintheri does not form spores and is killed by pasteurizing, the author found 

 that acidity caused the germs to adhere in small clumps and that some of them 

 do not succumb to pasteurizing. 



