AGRICULTURE AND RURAL ECONOMY. 375 



expressed his opinion that fat is formed from carbohydrates 

 by swine ; and this would probably prove to be the case with 

 other animals. With this view Dr. Gilbert, of Rothamstead, 

 seemed to agree. Henneberg, on the same occasion, presented 

 some calculations which led to the inference that 100 parts 

 of albuminoids may produce 51.4 parts of fats. 



Effect of Fodder upon Milk Production. 



The experiments of Kiihn at Moeckern on the effects of 

 different kinds and amounts of food upon the production of 

 milk by cows are coming to assume great importance. Eight 

 series made during the years 1867-74 have now been report- 

 ed. These include eighty-four single experiments with twen- 

 ty-six cows. Detailed accounts of those of 1870-73 were 

 commenced in the Journal filr Landwirthschaft for 1874, and 

 have just been completed in the volume for 1877. Only a 

 brief report of the eighth series has been published. The 

 later ones are not yet published. Dr. Kiihn has, however, 

 given, in a report of the work of the Moeckern station to 

 1877 (Landw. Vers. Stat., xxii., 133-143), a summary of 

 results to that time. It appears that after the ration has 

 reached a certain amount of food of fitting composition, (1) 

 increase of the food brings an increase of the total yield of 

 milk ; (2) the " richness " of the milk, the percentage of dry 

 or solid matters, increases at the same time ; (3) there is a 

 limit to this improvement in quality and amount of the milk, 

 varying with different breeds and individuals; (4) changes 

 in the composition of the rations, in the proportions of albu- 

 minoids, carbohydrates, and fats they contain, do not produce 

 corresponding changes in the composition of the solid mat- 

 ters of the milk. The proportions of casein, albumen, fat, 

 and sugar rise and fall parallel with each other ; at least, the 

 variations are slight, and not parallel with those in the in- 

 gredients of the food. 



In short, it does not seem practicable, by altering the qual- 

 ity of the food, to increase, for instance, the fat at the ex- 

 pense of the casein of the milk ; to change a " cheese cow " 

 into a butter cow, or vice versa. A few exceptions to this 

 rule have indeed been found. Two coavs out of thirty exper- 

 imented upon at Moeckern and Hohenheim have shown an 

 evident and some others an apparent relative increase in 



