1911.] PUBLIC DOCUMENT — No. 31. 87 



varying the proportion of the milk eonstituents. Armsby,^ as 

 well as Whitcher and Wood,- has drawn similar conclusions. 

 Morgan et aJs. conclude from numerous investigations that 

 protein is without specific influence in the formation of milk 

 fat.^ Kellner,'* in summing \\\) the results of numerous ex- 

 periments, especially of German 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 f(Jod groups exerts a very 

 pronounced influence. This influence is especially noticeable 

 in increasing the quantity 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 influence of difterent amounts of 

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

 re(piirements of dairy animals and also to study its influence 

 in modifying the })roportions of the several milk ingredients. 

 Some of these results have been published in reports of the 

 station. It is proposed to briefly summarize the results already 

 given publicity, and to describe somewhat in detail our more 

 recent observations. 



Experiment I.^ — 1895. 



This experiment was undertaken wuth six cow^s by the re- 

 versal method. The animals Avere from five 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 w^ere weighed once be- 

 fore feeding and watering at the beginning and end of each 

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

 of the experiment. 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. 



' Landw. Vers. Stat., 62 (100.5), nos. 4,5; pp. 251-286; Ahs. Experiment Station Record 

 Vol. 17, p. 286. 



* Die Ernahrung d. Landw. Niit^^thiere, erste Auflage, p. 519; aI.so, funfte Auflage, p. 539. 



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



