The effect of breed of chickens on resistance toEimeriainfections

Abstract

Five strains of chickens were examined for their susceptibility to several Eimeria infections. Mortality, body weight gain and oocyst production were used to measure effects on the host. The depression in the rate of body weight gain was accompanied by increased reproduction of the parasites. In general, mortality rates were also associated with increased reproduction of the parasites. A strain of Light Sussex chickens was more susceptible than one of Rhode Island Reds to E. acervulina, E. brunetti, E. maxima and E. mivati but was not shown to be more susceptible to E. tenella. Where used, Brown Leghorns (one strain) and White Leghorns (two strains) were more susceptible than the Rhode Island Red strain to the infections mentioned. It is suggested that the choice of breed or strain of chicken for experimental studies on the coccidia is important and that the innate resistance of some breeds or strains of chicken deserves further investigation.