MILK DEFECTS 71 



5. Stable-like, turnip-like, and beet-like tastes, and a 

 burnt or malt-like taste and odor are each caused by cer- 

 tain species of bacteria. 



6. Blue Milk. The Bacillus cyanogenus, also called 

 the Bacterium syncyaneum, produces a grayish color on 

 the surface of milk and, when the milk is sour, blue spots, 

 which may become confluent. There are several other 

 species of bacteria which produce a blue color in milk. 



7. Red Milk. Red spots or a diffuse red color on the 

 surface are produced by the Bacillus prodigiosus, also by 

 Sarcina rosacea and several other species of organisms. 

 The Bacterium lactis erythrogenis curdles milk, then 

 dissolves the curd and colors the fluid diffusely red. 



8. Yellow- or orange-colored spots are produced 

 usually by the Bacillus synxanihus; also by the Sarcina 

 lutea, Sarcina ftava and the Bacterium fulvum. 



9. A yellowish-green discoloration is produced by the 

 Bacillus pyocyaneus. 



10. Greenish-yellow spots and diffuse discoloration 

 may occur in sour milk as a result of the growth of the 

 Bacillus ftuorescens. 



11. Violet-colored spots are produced by the Bacillus 

 violaceus, Bacterium janihinum, Bacillus lividus and 

 Bacterium amethystinus. 



In some cases, although very rarely, these pigment- 

 forming bacteria are present in the udder. Usually, they 

 enter the milk after it is drawn from the udder. They 

 can generally be excluded by sterilizing the milk vessels 

 and cleaning and disinfecting the places where the milk 

 is stored; sunning it also if possible. Sometimes it will 

 also be necessary to clean and disinfect the stable and to 

 see that the cows are thoroughly cleaned before milking. 



