254 MODERN DAIRY PRACTICE. 



made from it, so as to make it unpalatable to the least par- 

 ticular palate. 



2. Oily Butter. This disease is characterized by a 

 disagreeable taste and smell in the butter, reminding one 

 of ordinary lubricating oils. Faulty methods of working 

 the butter or of feeding (as regards the composition or the 

 quality of the fodder) are often given as causes. Jensen's 

 investigations which are not yet furnished show, however, 

 that the disease is caused by a small oval bacterium be- 

 longing to the lactic-acid bacteria, which produced a firm 

 white coagulum in the milk within 12-24 hours. This at 

 the same time assumed a disagreeable, oily odor. The 

 bacteria thrived best at about 77 F. (25 C.); at ordinary 

 room temperature it developed somewhat more slowly. 



3. Root-taste (Turnip-taste). As is natural, this disease 

 was long believed to be due to a too liberal feeding of 

 roots; but Jensen has shown conclusively that the ap- 

 pearance of disease does not stand in any relation to the 

 method or system of feeding, but is caused by one or 

 more forms of bacteria which develop in the milk before 

 or during the ripening of the cream. In a sample of but- 

 ter suffering from this disease, Jensen isolated a staff -like 

 bacteria possessing locomotive power; this sample origi- 

 nated from cows that were not fed any roots. When the 

 bacteria was inoculated into milk or cream it caused " a 

 disagreeable, very bitter taste, reminding of turnips or 

 rutabagas." 



4. Rotten Taste. This very troublesome disease was 

 mentioned already in the introductory chapter (see p. 20). 

 It appeared in 1888 at Dueland and neighboring farms 

 (Denmark), and is caused by a bacterium carefully studied 

 by Jensen, and by him named bacillus fcetidus lactis. 



