84 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



kept; in fact, 95 pure-bred herds were established around Grove 

 City during the year. 



DAIKY DEMOXSTEATION FAKJI, DENISON, TEX. 



The farm near Denison, Tex., owned by a company of local busi- 

 ness men and managed by a specialist of the Dairy Division, which 

 was bought some years ago for the purpose of demonstrating the 

 possibilities of dairying on worn-out cotton land, showed a con- 

 siderable increase in gross income during the past year, due in part 

 to a better system of marketing. A reduction was made in the dairy 

 herd in order that the field o ops may fully feed the cattle. 



HOLSTEIN-FEIESIAN BKEEDING CIRCUIT IN NORTH DAKOTA. 



The experiment with a Holstein-Friesian breeding circuit in North 

 Dakota, begun in 1908, has been completed and the department's 

 financial assistance terminated. At first this was a community 

 project to demonstrate the effect of developing one breed of dairy 

 cattle. A single breed of dairy cattle was established, herd-record 

 keeping was introduced, and meritorious bulls brought in. The mem- 

 bers have made arrangements to continue the work for another 10 

 years. 



DAIRY RESEARCH LABORATORIES. 



Much of the research work is of a fundamental character and 

 applies to other industries as well as dairying. This is true of the 

 work on hydrogen-ion concentration, which involves the synthesis 

 of new dyes, and also the study of the molds concerned in the ripen- 

 ing of Camembert cheese. With certain molds it was found possible 

 so to adjust the conditions of growth that practically all the sugar 

 of a 10 per cent solution was converted into citric acid. This promises 

 to be of great economic value, since it makes possible the manu- 

 facture, in this country, of citric acid, the entire supply of which 

 is now imported. This acid is much used in tanning, dyeing, and 

 other industries. A great deal of information has been obtained also 

 regarding the classification and origin of the colon-aerogenes group 

 of bacteria. Because of its presence being an indication of fecal 

 contamination, this group is of special sanitary significance. The 

 results obtained have been incorporated in official methods of water 

 analysis. 



EFFECT OF SILAGE ON CEMENT. 



The use of concrete for silos has been criticized because of the sup- 

 posed injurious effect of acids upon cement. Careful investigations 

 have been carried on with oil-mixed concrete and with ordinary con- 

 crete coated with oil, tar, tar dissolved in gasoline, and cement wash. 

 "When in direct contact with silage both mixtures of concrete were 

 slightly affected. 



PHOSPHORUS AND CALCIUM IN MILK SECRETION. 



In the studies of the relation of phosphorus and calcium to milk 

 secretion considerable progress has been made, which, being of a 



