74 EXPERIMENT STATION RECORD. fVoI. 38 



the difference in the lactation and gestation periods of the cows used in the 

 experiments. 



No definite conclusions as to the protein requirements of dairy cows in 

 milli are suggested, but the results are thought to indicate that the standard* 

 proposed by Eckles is a safe guide for practical feeding. 



Standard cows, W. A. N. Robeetson {Jour. Dcpt. Agr. Victoria, 15 {1911), 

 No. 9, pp. 513-541, figs. i5).— This is the fifth annual report on the testing of 

 pedigree herds of dairy cows, conducted by the Victoria Department of Agri- 

 culture for the year ended June 30, 1917. During the year 265 cows completed 

 their 273 days' term. Of the three breeds represented, 176 Jerseys, 20 Ayrshires, 

 and 38 Red Polls obtained certificates, thereby becoming " standard cows." 

 The records of the certified cows for the year are tabulated. 



Should all heifers be raised? W. J. Fbaseb {Cream, and Milk Plant Mo., 6 

 {1911), No. 2, pp. 65-67). — It is noted that of a large number of cows tested 

 in dairy herds in different parts of the State the poorest third produced an 

 annual average of 3,654 lbs. of milk and 134 lbs. of milk fat, each cow lacking 

 about $7 of paying for her keep. The middle third of these cows averaged 

 5,000 lbs. of milk and 198 lbs. of fat and returned a yearly profit of about $7 

 each. The best third averaged 6,765 lbs. of milk and 278 lbs. of fat, each cow 

 making an annual profit of about $27. The author advocates saving only the 

 heifer calves from the best third of the cows, and these calves should be sired 

 by bulls from good producers. 



Age at first calving G. C. White {Jour. Dairy Sci., 1 {1917), No. 2, pp. 

 1S9-147, figs. 2). — Tabulated data are given showing the age at first calving 

 fend the milk and fat production during each lactation period of the 12 Holstein 

 cows in the Connecticut College dairy herd. Of the 10 of these cows which have 

 completed a year or lactation period, 5 are grouped as early calvers, or those 

 calving at 30 months of age or under, and 5 as late calvers, or those calving at 

 the age of over 30 months. The production for each lactation period of each 

 group is averaged and discussed. 

 No conclusions are drawn. 



Sunflowers as a silage crop, G. Lagkange {Jersey Bui. and Dairy World, 

 36 {1917), No. 45, p. 1749, figs. 2). — Sunflowers cut at the blooming stage were 

 successfully used as silage. Cows greatly relished the sunflower silage but did 

 not eat as much of it in bulk as they did of corn silage. 



Bacteriological methods for determining the quality of milk. I. — The re- 

 action of agar for the bacterial analysis of milk, J. M. Sherman and F. P. 

 Reynolds, jb. {Pennsylvania Sta. Rpt. 1915, pp. 294-299, pis. 5). — Comparisons 

 were made of agars with neutral, +0.5, +1, and +1.5 reactions, phenol- 

 phthaleln being used as indicator. The lactose agar plates were incubated for 

 48 hours at 37.5° C. Average counts of 10 plates each of 15 samples of milk 

 show much lower counts obtained with the +1.5 reaction than with the others. 

 In all these samples the +0.5 agar gave the highest counts. In a further com- 

 parison of +0.5 and +1 agars 12 samples were plated as above. In 9 of these 

 samples the higher count was obtained with the +0.5 agar. 



In order to get definite information on the size of colonies which develop on 

 agars of different reactions, pure cultures of four common milk organisms were 

 plated, and the colonies were measured with a micrometer. The organisms used 

 were Bacterium lactis acidi, BaoiUus coli, a liquefying coccus from the interior 

 of the udder (probably Micrococcus albus), and an udder streptococcus. The 

 ten largest colonies on each plate were measured except in the case of B. lactis 

 acidi in which case ten average sized colonies were measured. The colonies of 

 B. lactis acidi were measured differently because this organism produced a few 



