The influence of coccidiosis resistant, susceptible and unselected sires on progeny mortality after infection with Eimeria tenella.

After four generations of selection for resistance to E. tenella, resistant, unselected and susceptible, sires were mated to dams of an unselected population. Mortality from coccidiosis in their progeny following inoculation of every chick with 50,000 sporulated oocysts was only 3.7% in progeny of resistant sires, compared with 20% in progeny of unselected sires and 25% in chicks from sires of a susceptible strain.