326 ON THE MILK OF THE COW. 



Its composition shows that it should form a nutritious and fattening food, and one also well 

 adapted to produce milk of a rich quality. Horses are more fond of oil-cake than cows, and 

 it probably constitutes a kind of food upon which they can perform more work, and with less 

 fatigue than any other. 



Prof. Johnston of Durham, England, has placed the value of oil-cake in its true light. He 

 remarks that the percentage of the protein compounds, albumen and gluten, is nearly equal to 

 what is contained in pease and beans ; and that therefore, for the production of milk for the 

 cheese dairy, and for laying on of muscle, oil-cakes are as valuable as beans, pease and clover. 

 He goes on to remark, that this result is somewhat unexpected, inasmuch as their value, in the 

 feeding of stock, has hitherto been supposed to depend upon their power of laying on fat, in 

 other words, upon their percentage of oil. I subjoin his analysis of the English oil-cake : 



Water, 1005 



Mucilage, 39-10 



Albumen and gluten 22-14 



Oil, 11-93 



Husk, 9-53 



Sand, ash, &c 7-25 



The analysis which I made I had some doubt of the freedom of the fibre or husk from mu- 

 cilage. The proprietor of the establishment remarked, that occasionally there were portions 

 of the cake which contained impurities, sand, &c., and that tons of these foreign matters were 

 sifted out to his loss. Whatever may be the fact, as to impurities in particular samples of the 

 substance, there can be no doubt of its great value in feeding stock ; it is borne out both by 

 analysis and by experience. I may remark, in confirmation of this view, that the cake I em- 

 ployed for analysis was uncommonly impure and filled with sand, by the uncommon quantity 

 of sand which appeared in the ash. Prof Johnston estimates the amount of ash as at least 

 equal to 6 per cent. One-third of this ash is phosphoric acid ; 100 pounds of oil-cake, there- 

 fore, contains 2 pounds of phosphoric acid. On the other hand, wheat leaves only 2 per cent 

 of ash, of which one half only is phosphoric acid, or 100 pounds of wheat contain 1 pound of 

 phosphoric acid : therefore, for laying on bone, or supplying the materials of bone to growing 

 stock, oil-cake is twice as valuable as wheat, weight for weight, and more than twice as valu- 

 able as oats or barley, which are covered with husk. But this goes to sustain the view which 

 I have stated elsewhere, that flax must be an exhausting crop, inasmuch as the phosphates are 

 derived from the soil ; it follows that it is twice as exhausting as wheat. 



The influence of carrots on the milk of the cow. 



I fed my cow with half a bushel of carrots per day, after having finished, for the time, my 

 experiments with oil-cake. The temperature had very materially increased, and the weather 

 was comparatively warm, being a large proportion of the time above 40° of Fah. The car- 

 rots were crushed and fed without cooking : hay was allowed, and this feeding continued three 



