152 PARASITES OF THE DOMESTIC ANIMALS 



The parasitic life of the ticks, together with the blood-destroying- 

 properties of the protozoan parasites with which they inoculate their 

 hosts, causes a loss of flesh and lack of development in southern cattle 

 conservatively estimated at $23,250,000. 



The lower price which southern cattle from infested districts bring 

 in northern stockyards averages at least $1.50 per head. It is estimated 

 that the loss upon animals marketed under these conditions, including 

 stock, beef, and dairy cattle, will sum up to $1,057,500 annually. 



The shrinkage in milk production of cattle infested with many ticks 

 will average about one quart per day. Upon an estimate of 875,000 

 ticky dairy cattle out of more than 4,000,000 dairy cattle below the 

 quarantine line, the loss thus occasioned, reckoned at three cents per 

 quart, would amount to $26,250 per day, or, counting three hundred 

 milking days for each cow to the year, $7,875,000 annually. 



The loss among nonimmune southern cattle in tick-free pastures 

 through contracting Texas-fever when exposed to the tick has been 

 estimated at $5,812,500 per annum. 



The deaths from Texas-fever of pure-bred or high-grade cattle im- 

 ported from the North for breeding purposes amount to about sixty 

 per cent, among such cattle which have not been immunized by blood 

 inoculations, and to about ten per cent, among those which have had 

 such immunization. Since these are usually expensive animals, the 

 loss in such cases is often excessive. . 



Considering additional losses, direct or indirect, as published by the 

 United States Department of Agriculture in 1914, it will be found that 

 the Texas-fever tick is responsible for a loss of about $40,000,000 an- 

 nually, in addition to which it is responsible for lowering the assets of 

 the infested country to the extent of $23,250,000. 



Progress in Eradication. — Methods of dipping and pasture rotation 

 for the control of the cattle tick have been fully set forth in bulletins 

 and circulars published by the United States Department of Agriculture 

 (Farmers' Bull. No. 498). These are freely available to all interested in 

 details of the subject which need not be repeated upon these pages. 



Eradicative measures carried on by the Federal Government in 

 cooperation with the states affected by the cattle tick have seen in 

 progress since 1906. Up to 1911 twenty per cent, of the infested area, 

 mostly along the northern boundary, had been cleaned through this 

 systematic cooperative work. At the present time (1918), through the 

 continuation of this work, fifty-two per cent, of the tick-infested area 

 has been released from quarantine, and it is authoritatively predicted 

 that five years hence the cattle tick will be entirely eradicated from the 

 South. 



