810 EXPERIMENT STATION RECORD. 



tliOHci ohtairu'd (liirinjx tlu- first ami third periods, when only the control ration, con- 

 sisting for the most part of liay and wheat feed, was fed The nutritive ratio of the 

 rations was approximately 1:5.4. The fat content of the milk was determined 

 gravimetrically and by the Gerber method, and determinations were made of the 

 K()ttstorfer, Reichert-Meissl, and Hiibl numbers, the index of refraction, and the 

 melting point of the butter fat. Slaughter tests were also made in some of the 

 experiments. 



No constant relation was observed between the feeding of 30 or 50 gm, of rape- 

 seed oil per head per day and the yield of milk. Neither was there apparently any 

 S]>ecilic influence exerted by the fat in the food upon the pen-entage of fat in the 

 milk. The yield of fat on the whole was slightly increased by the feeding of rape- 

 seed oil and linseed oil. Cocoanut oil fed at the rate of 30 gm. per head per day 

 increased the yield of fat, and fed at the rate of 50 gm. decrease<l the yield. In 

 no case, however, was the increase in yield sufficient to justify, from a practical 

 standpoint, the intensive feeding of fat. 



In 3 of the experiments the results showed a specific influence of the fat in the 

 food upon the chemical comiiosition of the butter fat, while in the fourth experi- 

 ment no such influence was api)arent. Kape-seed oil and linseed oil decreased the 

 Kottstorferand Reichert-]\Ieissl numbers and increased the Hiibl and refractometer 

 numbers. Cocoanut oil in one experiment increased the K(")ttstorfer number and 

 decreased the Reichert-Meissl, Hiibl, and refractometer numbers, while in another 

 experiment it was apparently without influence in this respect. The melting point 

 of the butter fat was lowered to a slight extent by rape-seed oil and cocoanut oil, 

 and to a greater extent by linseed oil. The influence of feeding fat upon the chemical 

 composition of butter is considered as clearly established by the experiments of the 

 author and by the experiments cited in the article. 



Determinations were made of the Kottstorfer, Reichert-Meissl, and Hiil)l numbers 

 of the body fat of goats killed at the end of the different periods. While the Hiibl 

 numljer of butter fat was increased by the feeding of fat, that of the l)ody fat was 

 decreased. The results are discussed in relation to the hypothesis of Soxhlet, that 

 in the intensive feeding of fat the organism utilizes primarily the body fat rather 

 than the food fat in the production of butter fat, which hypothesis, as well as that 

 relating to the profitableness of such feeding, were not considered as confirmed by 

 the work reported. 



The source of milk fat, its changes, and experiments in the determination 

 of individuality in milk secretion, I. Dolgikii (.1;v7(. Vd. Ndiik, SI. Pfterxhurg, 

 33 {1903), Noa. 11, pp. lllS-1159; 12, pp. 1J43-13 Jo). —The literature of this subject 

 is critically reviewed in connection with bibliographical references, and an attempt 

 is made to draw from this mass of literature conclusions regarding the source of milk 

 fat and the individuality of milk secretion in different cows. 



It was found in a study of the literature that the time of the maximum production 

 of milk varied in different cows according to individual peculiarities, which could 

 not be definitely formulated. In general the quantity of milk produced was greater 

 when the cows were fed on a heavy ration than when fed on medium or light rations. 

 A considera])le difference, however, was observed in the ability of different cows to 

 make profitable use of large quantities of fat. The ability of yielding large quanti- 

 ties of milk and producing eorresiX)ndingly large quantities of milk fat appears to be 

 capa])le of increase, l)ut depends also to a considerable extent upon the potential 

 nervous energy of individual cows and upon the physical development of the' various 

 organs of the body. 



Influence of feeding and milking on the composition of milk, P. Dechambre 

 {Jour. Agricole iP(mi\, U {1903), Nos. 164, pp. 191-194; 165, pp. 216-219).— The 

 author discusses briefly the role of proteids, fats, and carbohydrates in the nutrition 

 of cows, the influence of various feeding stuffs upon the composition of milk, and 



