31 



food witbiu ordinary ranges; and hence, why it should be so difficult by 

 changes in the food to effect any change in the composition of the 

 organic substance of the milk. 



The practical inferences from these researches are thus summed up by 

 Kuehn : " The farmer will then infer that with milch-cows the richest 

 fodder is not always the cheapest. On the other hand too meager fod- 

 der is still worse. * * * * Here, as elsewhere, a fair mean will be 

 found best." As regards the effect of different foods ou the compositiott 

 of the milk, he says that the farmer may not hope by variation iu the 

 fodder to change a " butter cow " to a " caseiu (cheese) cow." He must 

 rather depend for the quality of the milk, the relative richness in fat or 

 caseine, its special fitness for butter-making or cheese-making, upon the 

 peculiarities of different breeds or different individuals, and for quantity 

 upon the peculiarities of the animals themselves ; or, iu few words, for 

 quality of milk, select proper breeds ; for quauMty, good milkers ; and 

 feed well but not over-richly. 



2d. Experiments to determine the proportions of different foods that are 

 digested by different animals. — In these not only the food but also the 

 excrement is accurately measured and its composition determined by 

 analysis. Of the food consumed by the animal a portion is digested, 

 while the rest passes oft' as excrement. If, then, the total amount of 

 the food consumed, and the amounts of its chemical constituents, 

 albuminoids, fat, carbo-hydrates, and mineral matters be known, and 

 the same factors of the excrement be determined also, we have only to 

 subtract the latter from the former, and we have the amounts actually 

 digested. ^ » 



A long series of experiments of this sort have been made at the station 

 at Weende, near Gottiugeu. They were commenced by Henneberg and 

 Stohman, in 1868, and have since been continued by them and by G. 

 Kuehn, Aronstein, Schultze, Wolft', Hellriegel, Lucanus, Hoffmeister, 

 Lehman n, Miircker, and others at Weende and elsewhere, with very 

 important results. The accounts of these researches are to be found in 

 the Journal filr Landwirthschaft, published at Gottiugen, and in the 

 LandicirthschaftUchen J' ersuclis-Stationen. 



Here follows a tabular statement of the mean results of sixty-six 

 experiments made with eleven different oxen at Weende. The figures 

 represent the average percentage of the different food-ingredients 

 actually digested from different food-materials. They are given bj'^ 

 Henneberg Keite Beitriige, Gottiugen, 1872, p. 449. 



It will be seen from these figures that the digestibility of different 

 kinds of straw and of the woody fiber of fodder-plants in general is 

 much greater than has ordinarily been supposed. 



The digestibility of root-fruits, grains, oil-cakes, &c., has also been 

 investigated by Henneberg and Stohiiiann, by Wolff", in Hohenheim, 

 Kuehn, in IMoeckern, Hoffmeister, in Dresden, and others. 



