EPIDEMIOLOGY OF GASTROINTESTINAL NEMATODE S OF CATTLE IN THE TREE-CROPPING PASTURE SYSTEM OF SENEGAL

From october 1990 until september 1991, 52 bovines in a tree-cropping pasture system were examined, all animals appeared to be infected with at least one of the following species of nematodes: Haemonchus contor tus was found in 92 %, Cooperia punctata in 88%, Oesophagostomum radia tum in 75% and Bunostomum phlebotomum in 54% of the bovines. In the ab omasum, the mean charge of adult Haemonchus contortus was 63 and 14 re spectively in january and february; while larvval stages reach 1635 an d 1203 respectively. During these two months, 96% to 99% of Haemonchus were hypobiotic. Adult Cooperia sp., Oesophagostomum sp. and Bunostom um sp. were found during the whole year. The results showed massive in festations of the animals during the rainy season with losses during t he dry season as a result from the combination of malnutrion and paras itisms. Haemonchus, constraint to bovine health and production.