1911.] PUBLIC DOCUMENT — No. 31. 87 



varying tho proportion of the milk constituents. Arnisby/ as 

 well as Wliitclier and Wood,- lias drawn similar conclusions. 

 Morgan et als. conclude from numerous investigations that 

 protein is without specific influence in the formation of milk 

 fat.'"' Kellner,"* in summing up the results of numerous ex- 

 periments, es])ecia]ly of (Jerman origin, says '' in so far as it 

 is possible by means of food to effect the action of the milk 

 glands, the protein of the several food groups exerts a very 

 pronounced influence. This influence is esp(H'ially noticeable 

 in increasing the quanlUij of the milk. Only after the long- 

 continued feeding of a ration known to be deficient in protein 

 does the water content of the milk increase, and the dry matter 

 and fat show a noticeable decrease." 



This station from time to time has conducted a number of 

 experiments to observe the infiuence of difl^erent amounts of 

 protein in increasing the quantity of milk, to note the protein 

 requirements of dairy animals and also to study its influence 

 in modifying the proportions of the several milk ingredients. 

 Some of these results have been published in reports of the 

 station. It is proposed to briefly summai-ize the results already 

 given publicity, and to describe somewhat in detail our more 

 recent observations. 



Experiment IJ' — 1805. 



This experiment was undertaken with six cows by the re- 

 versal method. The animals were from fi\'e to ten years of 

 age, had all calved in the early autumn, and none had been 

 served when the experiment began. 



Weighing Animals. — The animals were weighed once l)e- 

 fore feeding and watering at the beginning and end of each 

 half of the trial, and once each week during the continuance 

 of the ex]">erinient. It would have been better to have weighed 

 each animal for three consecutive days at the beginning and 



•Wisconsin Experiment Station, reports for 1885-86, New Hampshire Experiment Station, 

 Bulletin 90, pp. 12-14; Bulletin 18, p. 13. 



' Ibid. 



3 Landw. Vers. Stat., 62 (190.5), nos. 4,5; pp. 251-286; Abs. Experiment Station Record 

 Vol. 17, p. 286. 



* Die Ernahrung d. Landw. Niitzthiere, erste .\uflage, p.510; also, fiinfte Auflage, p. 539. 



5 Ninth report of the Hatch Experiment Station, pp. 100-125. 



