158 SCIENCE AND PRACTICE OF DAIRYING. 



will keep for some time, may be easily prepared with the separator. 

 In feeding pigs it is possible to increase the nutritive value of 

 skim-milk by feeding with potatoes at the same time. 



Under favourable circumstances, a kilo, of fresh skim-milk, as 

 a food for calves, may have a value of 3 pfennig. The utilization 

 of skim-milk as a food for other domestic animals, besides calves 

 and pigs, is very limited, and we need not deal with it here. 



Skim-milk possesses, on an average, the following composition : 



Old method. Separator. 



Water, 89-85 90*30 



Fat, 0-75 0-25 



Protein matter, ... 4 -03 4 -00 



Milk-sugar, ... 4-60 470 



Mineral matter, ... 077 0*75 



100-00 100-00 



Sp. gr. at 15 C., 1*034 1-035 



The analysis of the ash of a sample of skim-milk, obtained by the 

 separator, is as follows : 



Potassium oxide, 31*634 



Sodium oxide, 10*265 



Calcium oxide, 21-913 



Magnesium oxide, ... ... ... 3*115 



Iron oxide, 0-921 



Phosphoric anhydride, ... ... ... 19*478 



Carbonic anhydride, 1-000 



Chlorine, 15*071 



103-397 

 Deduct oxygen replaced by chlorine, ... 3*397 



100*000 



The 19*478 per cent of phosphoric acid includes that formed in the 

 burning of .the proteids containing phosphorus, and the sulphuric acid 

 arises entirely from the sulphur of the proteid substances. 



The value which a kilo, of skim-milk possesses in any district is very 

 easily determined. If it be known that 100 kilos, of milk, for example, 

 yield, on an average 3*5 kilos, of butter at 2 marks, and 16 kilos, of 

 butter-milk at -02 of a mark, the value of the cream will be 7*32 marks. 

 If the value of 100 kilos, of milk be assumed to be 12 marks, and if 78 

 kilos, of skim-milk be obtained from this quantity of milk, the value of a 



