MILK DEFECTS 69 
nish an environment favorable to their development. 
Measures for the correction of these defects must be 
based upon the source of the organisms concerned. 
1. Bitter Milk.—Several species of bacteria, yeasts 
and fungi have been isolated at different times from bitter 
milk. In some instances the organisms responsible for 
the bitter taste were found in the udder. Milk may ac- 
quire a bitter taste from the action of the organisms 
belonging to the peptonizing and gas-forming groups of 
the common milk bacteria. This is especially true of 
heated milk, in which the spores of the soil bacteria (hay 
and potato bacilli ) survive. The occurrence of a bitter 
taste in milk is often associated with the feeding of cer- 
tain substances, notably mouldy or decomposed fodder, 
beet and turnip leaves, and raw potatoes; also vetch, wild 
mustard and other cruciferous plants, leek, dog-fennel, 
tansy, etc. The use of mouldy or decomposed straw for 
bedding is accompanied by the same effect. It is believed 
that the bitter taste is caused by organisms which are 
present on these substances and which enter the milk 
after it is drawn from the udder, and it is recommended, 
therefore, that these feeds be given after milking, except- 
ing, of course, those which are mouldy or decomposed. 
Another theory is that the taste is due to a bitter sub- 
stance which is ingested with the food and eliminated 
through the udder. If milk is stored in rusted vessels 
until a certain degree of acidity develops, it acquires a 
bitter, astringent taste, due to formation of iron lactate 
or acetate. Milk may also have a bitter taste just before 
parturition and near the end of lactation. 
2. Viscid, “ Ropy,” or “ Stringy” Milk.—The milk 
is thick and viscid and when it is poured from one vessel 
to another strings are formed; it may also be drawn out 
