BULLETIN OF THE 



No. 147 



Contribution from the Bureau of Animal Industry, A. D. Melvin, Chief. 

 January 16, 1915. 



THE EFFECT OF THE CATTLE TICK UPON THE 

 MILK PRODUCTION OF DAIRY COWS. 



By T. E. Woodward and W. F. Turner, Dairy Division, and Cooper Curtice, 



Zoological Division. 



INTRODUCTION. 



The common cattle tick, Margaropus annulatus, infests the cattle 

 throughout the greater part of Florida, Georgia, Alabama, Louisiana, 

 and Arkansas, large portions of Texas, Oklahoma, Mississippi, 

 South and North Carolina, and small areas in Virginia and Cali- 

 fornia. On account of the enormous losses occasioned by the para- 

 site, it has been necessary to quarantine the area infested, so that 

 cattle outside of this area may be protected. Ever since 1906 tick 

 eradication in the infested area has been actively pushed by Federal 

 and State governments, cooperating with citizens of tick-infested 

 regions, to destroy the pest. WhOe the majority of farmers admit 

 some loss, few are aware of its extent, hence the experiments reported 

 in this bulletin were undertaken to bring out the facts, particularly 

 in relation to the effect of the tick on dairy cows. 



The cattle tick is an almost exclusive parasite of cattle. While 

 the ticks may mature on horses, mules, and possibly deer and sheep, 

 their control on these animals has proved to be comparatively easy. 

 AH ticks come from eggs laid by the adult female ticks. An engorged 

 female tick dropping from a cow completes oviposition in from five 

 days to a week; the eggs hatch as a rule in about 21 days in ordinary 

 summer weather; the issuing seed ticks crawl upon the grass and 

 await the coming of cattle upon which they crawl when opportunity 

 offers; they then reach maturity in from 21 to 25 days. 



While maturing each tick abstracts a definite amount of blood 

 from an animal, and to that degree injures it. The quantity of 

 blood abstracted is many times the weight of the ticks when grown, 

 for these represent only that part of the solids and fluids of the 

 blood which may be converted into the tissues of the tick, the remain- 

 ing solids and fluids being rejected. The amount of blood taken 



58970°— Bull. 147—15 1 



