The effects of wealth on livestock dynamics among the Datoga pastoralists of Tanzania

agricultura de subsistencia agriculture de subsistance animal production bovin caprin caprinos cattle commercialisation economic viability effectif du cheptel ganado ganado bovino goats hogares households livestock livestock numbers marketing mercadeo mortalidad mortalite mortality ovin ovinos pastoralism pastoralisme pastoralismo pobreza poverty production animale productividad productivity sheep subsistence farming tanzania tanzanie