EFFECT OF CATTLE TICK ON MILK PRODUCTION. 17 
the milk flow decreased faster in the heavily infested than in the 
lightly infested cows. This is additional evidence that the tick is a 
great hindrance to profitable dairying in the South. Even in so- 
called immune cattle, ticks cause irritation of the skin and withdraw 
blood that otherwise would produce milk or meat. 
Fever-producing parasites are present in the blood of cattle once 
infested by ticks, though they may be so few in number that no 
symptoms of the disease are apparent. The danger from them lurks 
there, nevertheless, for under certain conditions the parasites may 
multiply so rapidly as to cause marked disease or death, or they may 
be transferred by ticks to uninfected animals. Thus the tick con- 
stitutes a source of danger, and should be exterminated. Further- 
more, eradication must be by cooperative, concerted action. One 
farmer may free his premises of ticks, but reinfestation is liable to 
occur at any time from neighboring farms or strange cattle, unless 
the entire community is free from the tick. 
The only means of preventing losses by ticks is through disinfection 
and clean pastures. While dipping may temporarily diminish the 
quantity of milk given, in the long run it largely conserves the flow 
of milk. The arsenical solution should be used to frustrate the great 
dissemination of ticks during their most favorable season. In infected 
areas where there is no concerted effort to eradicate ticks it may not 
be wise to use the solution on slightly infested milch cows. 
Methods of exterminating the ticks on the farm are described in 
Farmers' Bulletin 498, a copy of which will be mailed to anyone on 
application. 
