Resistance of sheep from different genetic groups to gastrointestinal nematodes in the state of São Paulo, Brazil

Infections by gastrointestinal nematodes cause large losses to sheep breeders. In the study reported here, the resistance to gastrointestinal nematodes was analyzed in sheep of adapted and non-adapted breeds, maintained in naturally infected pastures. A total of 134 females from seven genetic groups were monitored during 20 months: Santa Inês (OSI), Dorper (ODO), Texel (OTX), Ile de France (OIF), and animals from crosses of Santa Inês ewes with...