ANIMAL PARASITES OF CATTLE. 



By B. H. Ransom, Pli. D., 

 Chief of '/joological Division, Bureau of Animal Industry. 



The animal parasites of cattle comprise more than a hundred 

 different species, belonging to various groups of the animal Idng- 

 dom. Fortunately not all these parasites occur in this country — 

 many are uncommon, and many are comparatively harmless. Some 

 forms, however, occur frequently, and some are of distinct impor- 

 tance to the American stockman on account of the damage for which 

 they are responsible. It is these parasites particularly which will 

 be referred to in the present article, and although some forms are 

 discussed which are rare or apparently of little economic importance, 

 most of the minor and miusual parasites and species not found in 

 this country have been omitted from consideration. ^ 



FLIES.^ 



Of the various species of flies which infest cattle some are inju- 

 rious on account of the annoyance, pain, and loss of blood due to 

 their bites, and sometimes also on account of diseases or parasites 

 which are thus transmitted from the blood of diseased animals to 

 that of healthy cattle, while others, which in the winged adult state 

 do not bite, are injurious because they live parasitic on cattle during 

 their larval stages. 



Bemedies for flies.'^ — Most remedies used for protecting cattle 

 from the attacks of flies have to be applied frequently, and few, if 

 any, will keep flies away for more than a day or two following their 

 application. The numerous proprietary fly repellents to be found 

 on the market are usually more expensive, and often less efficacious 

 than homemade mixtures. 



At the Minnesota experiment station rancid lard 1 pound and 

 kerosene one-half pint, mixed thoroughly until a creamy mass forms, 

 was found to give excellent results as a fly repellent, lasting for two 

 or three days, when rubbed not too thickly with a cloth or with the 

 bare hand over the backs of cows. Mixtures of cottonseed oil and 



T- Fiirtlier information may be found in a very full report on " Insects Affecting 

 Domestic Animals," issued as Bulletin 5, new series, of the Bureau of Entomology of this 

 department. 



- Further information on fly repellents may be found in Bulletin 131 of the Department 

 of Agriculture. 



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