RESUMEN
BACKGROUND & OBJECTIVES: Trypanosomiasis has remained a major set-back in the development of livestock farming in tropical Africa. Thus the need for ascertaining the trypanotolerant levels of domestic animal breeds and possible improvement on them cannot be over-emphasised. METHODS: Level of trypanotolerance in animals was compared between sexes using albino mice infected with a Nigerian strain of Trypanosoma brucei brucei at a 50% mouse lethal dose (MLD50). RESULTS: The male mice showed unrestrained parasite growth with a prepatent period (PP) of two days and a mean survival period (MSP) of six days corresponding to a gradual decrease in packed cell volume (PCV), body weight, diet response and white blood cells (WBC) count to the time of death. Their female counterparts showed a PP of three days and MSP often days with a similar PCV gradient but a refractory WBC count. There was no significant difference in the differential leucocytes count in both sexes. However, the eosinophils count was significantly higher in the infected animals. It was found that female albino mice exercised more parasite restraint than their male counterparts. INTERPRETATION & CONCLUSION: The result suggests that the female animals may be more trypanotolerant hence may be more useful in protein production in trypanosomiasis endemic areas. However, further research using large domestic breeds like goats and sheep may be required to confirm the hypothesis.