Fish Nutrition Research for Semi-Intensive Culture Systems in Asia

Abstract

Asia, considered the cradle of aquaculture, accounts for over 80% of the world's production. Most finfish production is of omnivorous/herbivorous species, cultured ex­tensively and/or semi-intensively. In the light of increasing, conflicting demand for land and water, to be cost-effective, culture practices need to be intensified to varying degrees, mostly through increasing levels of supplemental feeding. Feed cost is one of the highest, if not the highest, operational cost in aquaculture. Because of these developmental trends, fish nutrition research has become in­creasingly important. However, most research has followed basic nutrient requirement approaches often based on developed-country priorities. There is increasing evidence that the gross nutrient requirements of cultured. species groups are close to one an­other. Equally, diet development aimed at reducing feed cost by substitution of the fishmeal component, an ingredient not readily available in rural Asia, by agricultural by-products has been mostly confined to laboratories and findings are difficult to ex­tend to farm conditions. This paper considers the above aspects and suggests strategies for fish nutrition research, particularly where funding and personnel are increasingly limited. These strategies essentially encompass a holistic approach to research on feed-cost savings carried out on farm at minimal cost, primarily through research on improved hus­bandry, and taking into consideration the natural environmental inputs under tropical culture conditions.