Parasite burdens and host susceptibility of Zebu and N'Dama cattle in village herds in Gambia.

Helminth and tick burdens of N'Dama cattle kept in village herds were compared with parasite burdens in Zebu cattle introduced into the same herds. The animals were monitored regularly for tick and helminth burdens, and blood samples were examined for differential white cell counts. The Zebu were found to have significantly higher numbers of endo- and ectoparasites. The N'Dama had significantly higher levels of circulating eosinophils than the Zebu during peak parasite burdens. No difference in antibody levels to Amblyomma variegatum infestation could be detected between the two breeds. It is suggested that observed differences in susceptibility to endo- and ectoparasites between the two breeds cannot be totally attributed to environmental naivety of the Zebu, but must be partially owing to enhanced innate resistance factors in the N'Dama.