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. 



