that treated animals gained 73 pounds more per head than untreated 
checks under identical management, range, and handling conditions 
over a period of 61 days. Much more work of this nature is needed. 
However, if 10 pounds per animal is lost in only 10 percent of the 
cattle in the United States, an annual loss figure of $20 million 
is reached. 
Several species of ticks affect cattle, especially in the South 
and West. They reduce weight gains and heavy infestations some- 
times kill the animals. Ticks also predispose cattle to screw- 
worm attack by breaking the skin. Losses in cattle due to ticks 
are estimated at $13,800,000 annually. 
Four species of mites cause an estimated annual loss of $4,500,000. 
Goats and Swine 
Lice and mites on goats cause $800,000 annual loss through reduced 
weight gains and unthriftiness. There is also a loss of mohair 
due to rubbing against fences and other objects. The loss caused 
by this group of pests on swine is estimated at $3,100,000 yearly. 
Poultry 
About 4O species of mites and 10 species of ticks and fleas af- 
fect poultry in the United States, These pests cause unthrifti- 
ness, loss of weight and egg production, and some mortality, ese 
pecially in young stock. Edgar and King 8/ studied the effect of 
one species of louse on egg production, body weight, and food 
consumption in Alabama. He concluded, "The difference in net 
income between louse-negative and louse=positive flocks could be 
30 to hO percent. This could mean approximately 75 to 85 cents 
more per louse-negative bird.” The average annual loss to the 
poultry industry has been estimated at $80 million. 
Sheep 
Mites, bots, lice, keds, and ticks take a toll of sheep in re- 
duced weight gains and wool production and in general unthrifti- 
neSSe 
Miscellaneous Insect Pests 
Mosquitoes are a constant source of annoyance to cattle, and 
occasionally livestock has been killed by swarms of mosquitoes. 
8/ Edgar, S. He. and D. F. King. 1950. Effect of the body 
eae Eomenacanthus stremineus,on mature chickens. Poultry Sci. 
29(2)8 ~219, 
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