LONG-TERM EFFECTS OF AN EXPERIMENTAL-INFECTION WITH TRYPANOSOMA-CONGOLENSE ON REPRODUCTIVE-PERFORMANCE OF TRYPANOTOLERANT DJALLONKE EWES AND WEST-AFRICAN DWARF DOES

Ten West African Dwarf (WAD) does and 12 Djallonke ewes were artificia lly infected with a West African strain of Trypanosoma congolense and observed over two years. The infected animals showed a chronic anaemia together with a persistent parasitaemia but very low mortality and in crease in body weights was not significantly different from the contro l. In the infected sheep significant differences were found in offspri ng production at three and five months due to a higher mortality among the lambs. The infected goats had more abortions and stillbirths and period to first kidding, total number of parturitions, production at b irth, one, three and five months were significantly different from the controls. A productivity index was calculated and revealed that a chr onic T congolense infection significantly decreases the productivity o f WAD goats during two years whereas in Djallonke sheep, the loss in p roductivity is recovered after one year. Although both species are reg arded as trypanotolerant, the Djallonke sheep show a better tolerance to a chronic T congolense infection that the WAD goats.