Despite continued pursuit of development interventions to improve people’s livelihoods and reduce poverty, intended and actual outcomes of developments interventions may differ. Some scholars attribute this variation to flawed conceptualisation of development interventions while others view this divergence as evidence that implementation processes are complex and actual outcomes result from adaptations of the interventions by actors. To move beyond the discursive approaches to analysis of development interventions, this thesis addresses the question how do actors adapt them, why and with what outcomes in the long run? Empirically, it looks at how project officers and farmers adapted the National Dairy Development Project (NDDP), a dairy intervention implemented in Kenya between 1980 and 1995, and its long run outcomes. The intervention promoted zero grazing, intensive management of dairy cattle whose implementation by farmers was expected to increase land productivity as a means to address land scarcity, increase milk production and reduce poverty through generation of incomes from milk sales. The methodology of this thesis links mechanisms, contexts, and outcomes, three elements of realist explanation, to understand adaptations and outcomes of development interventions. Through thematic synthesis of in-depth interviews and analysis of project documents, this thesis explains adaptations and long run outcomes of the NDDP. Findings reveal that developers and farmers adapted several components of the intervention. With close reference to context, incentives and continuity pressures, this thesis utilises intervention effectiveness and matching mechanisms to explain how project officers adapted the NDDP. Further, through fit and resistance mechanisms, this thesis explains how farmers adapted zero grazing in the context of inadequate fodder, labour shortage and lack of resources to invest in dairy. In the long run, findings show that the intervention diminished as evident in coexistence of indigenous and modern dairy technologies and non-implementation of any dairy technologies by farmers. Despite adaptations of zero grazing by project officers and farmers, intensification of dairy cattle management has diminished in the context of resource constraints, neoliberal policies and labour shortage. Consequently, the objective to increase land productivity through intensive dairy cattle management, the rationale for initiation of the intervention, remains unresolved. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2014.