[Trypanosomiasis and trypanocidal treatments in Ndama calves in a glossina infected area (the ranch of Madina-Diassa in Mali)].

This work aims at contributing to the knowledge of trypanosomiasis epidemiology in calves of trypanotolerant breeds and at defining an appropriate treatment to improve the survival of such calves in a tsetse infested area. The first study was a parasitological survey of 100 calves from the day of birth to the age of one year. According to the results of this survey, the period from birth to three months is a "critical" moment in the life of the calves, due to a high infection rate and mortality related to trypanosomiasis. The purpose of the second study was to investigate the possible interference of early trypanocidal treatments with the further expression of trypanotolerance. For this purpose three groups of over one-year old animals were established. The groups had different trypanosomiasis history due to the different treatments they had undergone during their first year of life. All the animals had been exposed to trypanosomiasis without treatment and followed up parasitologically and clinically during the second year. The results showed no interference of early trypanocidal treatments (including preventive ones) with the expression of resistance in potentially trypanotolerant animals.