Book excerpt: Significance of Trypanotolerance as a control option; Trypanotolerant livestock, a sustainable option for increasing livestock production in tsetse-affected areas; Biology of Trypanotolerance; Factors affecting estimation of tsetse challenge and the expression of trypanotolerance; Field research on measurement and use of trypanotolerance criteria to enhance trypanotolerant livestock productivity; Field research on measurement and use of trypanotolerance criteria to enhance trypanotolerant livestock productivity: 1. ILCA's achievements and future plans; Field research on measurement and use of trypanotolerance criteria to enhance trypanotolerant livestock productivity: 2 recent results quantifying trypanotolerance indicators; Genetic improvement of growth parameters in N'Dama cattle in Mali; Characterization and mechanisms of trypanotolerance in Baoule cattle; Antibody responses to the surface-exposed epitoses of the trypanosome variable surface glycoprotein in N'Dama and Boran cattle; Antibody responses to invariant antigens of Trypanosoma congolense; CD5+ B lymphocytes in cattle infected with African trypanosomiasis; Comparative bone marrow responses during Trypanosoma congolense infection in N'Dama and Boran cattle; Markers for mapping trypanotolerance genes; The Orma Boran - ten years of field observations; Variation in susceptibility to tsetse-borne trypanosomiasis among Bos indicus cattle breeds in East Africa; Variations in susceptibility to the effects of trypanosomiasis in East African zebu cattle; Adoption, utilization and impact of Trypanotolerance; Promotion of N'Dama stockbreeding and extension activities in village herds in the Yanfolila area of Mali; The economics of trypanotolerant cattle production in regions of origin and areas of introduction; Cattle breed preferences and breeding practices in southern Nigeria; Salvaging the image of the N'Dama breed: productivity evidence from village production systems in The Gambia; Ecological, social and economic impacts of trypanotolerance: collaborative research in Central and West Africa; Conservation, preservation, enhancement and propagation; Characterization, conservation and utilization of indigenous African animal genetic resources - ILCA's proposed program; Progress in molecular and genetic characterization of cattle populations, with emphasis of African breeds; Multiplication of improved trypanotolerant livestock; Programme for conservation of domestic animal diversity: a food and agriculture organization contribution to conserving animal genetic resources; Breeding biotechnologies.