Tsetse Control in the Yalé Agropastoral Zone (Burkina Faso): Results of Socio-economic Surveys. The study examines the impact of a tsetse campaign (1994-1997) in southern Burkina Faso. In the absence of health - productivity monitoring, data were collected in cross sectional surveys to generate quantitative estimates of relevant productivity traits for cattle. The results indicate the following: 25% increase in herd size; reduction in mortality from 63.1% to 7.1% and increase in live births of 57.6%. Milk yield rose from 0.2 to 2.2 litres/cow/day in the dry season. These results show the impacts trypanosomosis control can have on zebu cattle exposed to a high tsetse challenge. The study underscores the importance of well designed surveys as a cost-effective way of generating estimates of productivity impacts. These estimates can be a useful alternative to subjective assessments in modelling the economic benefits.