Resistencia a los parásitos externos en algunas razas de bovinos

Abstract

Data is hereby presented from experimental evidence which proves the greater resistance to ticks (Baophilus sp) and "tórsalo" (Dermatobia hominis) of "cviollo" cattle from Nicaragua and Honduras, of the tropical milking criollo type

Crossbred cattle of balf breed Brown Swiss x Zebú breeding, showed com-parable vesistance to some of the criollo strains but, were more susceptible than the best strain of criollos The greatest susceptibility was shown by Emopean cattle, represented by the Jersey breed.

No significant correlation was found between susceptibility to one parasite and susceptibility to the other. Significance may be attached to the empirical ob-servation, that those animals which showed the least number of parasites counted, haves a marked resistance to skin punctme by a bypodermic needle.