Dynamique des infections trypanosomiennes chez des bovins Borgou à la ferme de l'Okpara au Bénin

Dynamics of Trypanosome Infections in Borgou Cattle at the Okpara Ranch in Benin. The dynamics of trypanosome infections have been studied over a period of 12 months in 55 Borgou cattle at the Okpara ranch of which 5 adult bulls, 20 young males and 30 calves. Moderate and temporary weight losses were observed both in infected and uninfected animals which indicates that these are not directly linked to trypanosome infections. Based on parasitological examinations the cumulative infection level reached 95% in young males and 80% in adult bulls, which is much higher than in calves (30%). The results show that the critical age for infection at the ranch is between 1 and 3 years old. These high infection levels indicate the occurrence of infected tsetse flies on the ranch. Therefore, the choice of trypanotolerant cattle is fully justified. Given the fact that the infection level of the calves remains zero until seven months of age and reaches only 3% at 8 months, the systematic trypanocidal treatments which are currently given to 2 month old calves have only a marginal benefit.