18 Milk and Its Products. 
per cent of fat is recorded from any cow giving as 
much as 15 pounds of milk per day. Any analysis 
above 7 per cent is extremely rare, and should be 
regarded with suspicion unless well authenticated. 
The mixed milk of herds seldom falls below 3 per 
cent of fat and rarely rises above 5.5 per cent. 
Colostrum.—The first milk secreted by the animal 
after parturition is quite distinct in composition and 
physical properties from that produced after the 
secretion has become well established. Such milk 
is called colostrum, and is ordinarily considered 
unfit for consumption or manufacture. Colostrum 
differs from common milk chiefly in its less propor- 
tion of water, in the much greater proportion of 
albumin and ash, and in the presence of small 
organized bodies known as colostrum corpuscles, which 
are probably debris of the cell structure of the gland. 
The percentage of albumin in colostrum is so great 
that it will cause the whole amount of milk to 
thicken upon boiling, and this is ordinarily consid- 
ered a sufficient test for determining the suitability 
of the milk for consumption or manufacture. With- 
in four or five days after calving, the milk loses its 
colostrum character and takes on its normal condi- 
tion. This change is a gradual and progressive one, 
and is more or less dependent upon the physical 
condition of the animal. When the cow is feverish, 
or when there is local inflammation in the udder, 
the colostrum character of the milk is retained 
for a longer period than otherwise. The amount 
of coloring matter. DUSSiMbosolf also considerably 
