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OHIO EXPERIMENT STATION: BULLETIN 356 



animal. Therefore dusting is not as expeditious as is dipping; 

 however, after a little experience the sheep can be dusted at the 

 rate of one in every 10 to 15 minutes. This can be readily accom- 

 plished if the man opening the wool moves his hand along with 

 sufficient rapidity to maintain a constant operation of the gun and 

 a uniform spray of dust. 



The amount of material used is another important item and 

 materially effects the cost of the operation. In the treatment of 

 the 104 ewes only 5 pounds of sodium fluorid was used. At this 

 rate it would take only about six-tenths of an ounce to one sheep. 

 Thus at 50 cents per pound (the price paid for the material) the ex- 

 pense for the salt would average less than 2 cents per sheep. 



Louse in sheep's wool. 



While the statement cannot be made that one dusting with 

 sodium fluorid is a completely effective remedy for sheep lice, yet 

 the salt may be used in winter to check their ravages until warmer 

 weather when sheep may be safely dipped. Two days after the 

 sheep were treated we found a half-dozen lice on a few of the sheep 

 examined. Bishopp states that the action of sodium fluorid when 

 applied in dust form on poultry is comparatively slow, hence if an 

 examination is made the day following or even 2 or 3 days later, 

 some lice may be found ; but the action of the powder persists, and 

 after 4 or 5 days all lice disappear. However complete oxtermina- 



