Raising pigs is a common income generating activity in Vietnam. Many farmers in the north of the country use fresh sweet potato as the main pig feed. This makes good use of a crop which does not sell so well, and the pigs provide manure for the farm. This integrated system is very important to rural household economies.
Scientists from the International Potato Center (CIP), together with Vietnamese collaborators from various institutions and disciplines, began working together in 1997 to improve these sweet potato based pig-feeding systems in northern and central Vietnam. Three main improvements were tried through the Participatory Technology Development approach: