34 MILK IN THE UDDER 
cells of animal matter. Some of these particles 
have broken off and are in the center of the 
milk channels, from which they will be discharged 
with the milk. 
BACTERIA IN THE UDDER 
When a cow lies down, dirt may be pushed 
into the ends of the teat, carrying with it bac- 
teria. A scratch on the surface of the udder 
from a barbed-wire fence, or a wound from a 
bruise may become infected. Through such en- 
trances, bacteria find their way into the interior 
of the udder and start an inflammation. It is 
nearly as common for a cow’s udder to become 
inflamed as for a human being to have a cold 
in the head. The bacteria irritate the interior 
of the udder by the poisons which they produce. 
To offset this, the blood discharges enormous 
numbers of white blood cells supplied by nature 
to entangle the bacteria and carry them off. 
This white material is commonly called pus, 
and is often seen by the milker as thick or lumpy 
matter discharged with the milk. The bacteria 
commonly causing such udder inflammations may 
cause tonsilitis or septic sore throat in milk con- 
