88 ELEMENTARY TREATISE ON STOCK FEEDS AND FEEDING 



the higher dry matter are also higher in nitrogenous substances 

 and ash, and lower in sugar than those lower in dry matter. 



Milk By-Products. Skim milk, buttermilk and whey are the 

 principal milk by-products used for feeding live-stock, i. Skim 

 milk is obtained by allowing milk to stand skimming off the 

 cream or by separating it by centrifugal force. 2. Buttermilk 

 is what remains after making butter. It has about the same 

 composition as skim milk. 3. Whey is the by-product obtained 

 in making cheese. The fat and casein of the milk are removed 

 in cheese making. 



COMPOSITION OF Miuc BY-PRODUCTS 



Skim milk and buttermilk run lower in water and higher in 

 nitrogenous substances than whey. Therefore whey is more of 

 a carbohydrate food than skim milk and buttermilk. 



Packing House By-Products. From the packing houses come 

 tankage, dried blood, meat scraps, bone meal, and meat and bone 

 meal. These products are sometimes fed to hogs and are ex- 

 cellent for poultry. Tankage is composed entirely of animal 

 matter. It consists of meat and T)one (from which the fat has 

 been extracted) and more or less dried blood. It is variable in 

 composition, but it usually contains a high content of protein. 

 Dried blood is simply what the name signifies. It has a black 

 brown color and is ground very fine. It is sold as red blood 

 and black blood; the red blood being of higher protein composi- 

 tion. Bone meal is finely ground bone and is generally sold 

 after the fat has been extracted because of its better keeping 

 qualities. 



