220 SCIENTIFIC FEEDING OF ANIMALS 



Sour milk often causes severe and even fatal 

 scouring in young stock, but faulty (blue, yellow, 

 salty, bitter) milk, if boiled, can often be used with- 

 out any bad results ; it is best, though, to give it 

 to older animals. 



Milk from animals suffering from contagious 

 or infectious diseases (tuberculosis, foot and mouth 

 disease, etc.) is the best carrier of infection to other 

 animals, but if the milk is heated to about 190 F., 

 or, better still, boiled for a few minutes, the danger 

 is removed. 



Separated milk from efficient separators does not 

 usually contain more than -05—2 % of fat, whilst the 

 skim milk from the old process of skimming still 

 retains -75-1 % of fat. What has been said 

 previously regarding whole milk applies equally to 

 separated or skim milk, save that the smaller 

 quantity of fat means a less nutritive value. The 

 use of separated milk, and also of whole milk, 

 is discussed in Part III of this book. 



Butter-milk, according to the method of butter- 

 making, has the properties of either sweet or more or 

 less sour separated milk, and contains on an average 

 •4—5 % fat. Sour butter-milk, like sour separated 

 milk, is best used for fattening pigs ; calves and 

 young swine are not able to make much use of it dur- 

 ing the first few weeks of life, and even later only 

 moderate quantities, always boiled, should be given. 



Whey which is left after the coagulation of the 



