Gastrointestinal nematode infection in ewes raised in an arid zone of Venezuela

the necropsy of a total 72 ewes coming from the venezuelan arid zone (state of falcón) was carried out as follow: 6 ewes per month; 30 during rainfall period and 42 during the dry period. the following nematode species were identified: haemonchus contortus, trichostrongylus axei, t. colubriformis, cooperia fuelleborni, c. pectinata, c. curticei, c. punctata, trichuris ovis, oesophagostomum columbianum, skrjabinema ovis and bunostomum trigonocephalum. the values of the bulla's diversity and evenness indices for the infracommunity of strongylids of ewes during the dry and rainfall periods, evidenced a low diversity and an unequal numerical repartition of species within the community. the sorensen similarity coefficient (css = 77%) showed a high similarity between the parasite species composition of communities from both periods. however no relationship between the structural patterns of the community was observed (rs = -0.08)