Harnessing the sacred beast: introducing ox-cultivation to the pastoral Toposa, Southern Sudan

agricultura tradicional agriculture traditionnelle boeuf buey bullocks cambio social changement social comportamiento humano comportement humain draught animal cultivation entorno sociocultural environnement socioculturel extension extension activities human behaviour innovation modernisation modernization nomadism nomadisme nomadismo pastoral society sistemas de valores social change sociedad pastoral sociocultural environment soudan sudan traditional farming transhumance trashumancia value systems vulgarisation