ABSTRACT

Many reports now indicate that cattle that survive trypanosomiasis, with or without the aid of chemotherapy, gradually become more resistant to challenge. The exploitation of trypanotolerant breeds of cattle offers one of the most important approaches to the control of the continental problem of African trypanosomiasis in animals. The survival or resistance trait has been termed trypanotolerance and is generally attributed to the taurine breeds of cattle in West and Central Africa, namely the N'Dama and the West African Shorthorn. While trypanotolerant breeds are a well-recognized component of livestock production in certain areas of Africa, they represent only about 5% of the total cattle population in the 38 countries where tsetse occur. The skin reactions that develop after bites with trypanosome-infected tsetse are much shorter, and the time to parasitaemia is much longer than in susceptible cattle, suggesting that parasite growth is being controlled at the level of the skin.