COLOSTRUM 13 
reduced to the amount normally found in milk. Oxydase 
and peroxydase may be absent for thirty hours or less 
following parturition, but after that time they are usually 
present (Gruber). 
The bactericidal power of colostrum is greater than 
that of milk. 
Change from Colostrum to Milk.—The secretion of 
the udder changes gradually in appearance and com- 
position until, in about a week after parturition, it be- 
comes milk. According to Weber, the consistency is 
changed to that of milk by the second to the fifth day, 
usually by the third; the color by the third to the eighth 
day, usually by the fifth, and the reaction by the seventh 
day, although this is variable. The colostrum bodies 
persist for variable periods. In some cows they continue 
to be present indefinitely in small number, while in 
others they are absent even in the first days of secre- 
tion. Shortly before the lactation ceases they again be- 
come numerous. 
Judgment of Colostrum as a Food for Man.—While 
colostrum is of great value to the new-born calf, it is 
not considered desirable as human food. It has not been 
proven to be injurious to the health of man, but the 
odor and taste are obnoxious, and its appearance is unap- 
petizing. Regulations of local health authorities for 
the control of milk supplies, therefore, forbid the sale of 
the product of a cow for food purposes usually for one 
week after parturition, and also for fifteen days before. 
It has been proposed by Weber that the use of the udder 
secretion be prohibited for general food purposes as long 
as it coagulates when boiled (2 to 4 days), and that its 
use for children be forbidden as long as it continues to 
react to the alcohol test (4 to 12 days). 
