The National Inland Fisheries Institute, NIFI, situated on the campus of Kasertsart University in Bangkok, was established by the Directorate of Fisheries with assistance from USAID and the Canadian International Development Agency, CIDA. In 1979 it was designated one of four lead centres for research and training in aquaculture Centres in Asia, NACA (RAS/76/003). The project receives support from UNDP in the form of experts and equipment.
In March 1980, the Aquaculture Development and Coordination Programme (ADCP) of FAO, responsible for the organization of the project, fielded a task force to formulate the research programme for the lead centre with respect to culture systems considered important to the development of aquaculture in the region in general and in the country in particular. Among areas identified as requiring particular attention was the development of efficient and economical diets, using local ingredients, for intensive culture of selected species.
Some diet formulation work had been initiated under two earlier FAO/UNDP country projects relating to catfish (Clarias batrachus and C. macrocephalus) and Macrobrachium culture. Similar work was started, under NIFI's own research programme, involving other species of commercial importance, viz., snakehead (Ophicephalus striatus) and Pangasius. Much of this work, however, is based on the use of purified or semi-purified diets specifically designed for determining nutrient requirements of the respective species. Nevertheless, useful knowledge has been obtained, especially with regard to protein requirements for growth, and experience gained in the production of water-stable pelleted feed.
The traditional feed employed in commercial catfish culture in Thailand consists of a mixture of trash fish and rice bran usually in a 9 to 1 ratio. This mixture is extruded through a motor-driven meat mincer fitted with a 4 mm die. The pelleted product containing 60–70 percent moisture is prepared fresh and fed, twice daily, at a rate of 10 percent body weight, by broadcasting into the pond. Recent modifications include replacement of 10 percent of the trash fish with cooked broken rice, serving as an energy source. With the expansion of the poultry processing industry, chicken entrails are also becoming increasingly available as a substitute for diminishing supplies of trash fish. Some farmers use this new feed resource exclusively for feeding snakehead in ponds. Advantages of a feeding system based on the use of trash fish and chicken offal are: (a) low cost; (b) simple technology; (c) readily available ingredients with the possible exception of trash fish; and, (d) fairly good water stability of the feed. Major disadvantages include: (a) uncertain quality and composition of trash fish depending upon its stage of deterioration; (b) undetermined value of chicken offal as an exclusive feed for fish; (c) high biological demand of unconsumed feed in water; and, (d) extremely short shelf-life of unrefrigerated moist pellets containing raw animal protein. Disease outbreaks that frequently occur in ponds employing the traditional system of feeding appear to be associated with one or more of these disadvantages. While commercial, dry, pelleted feeds for catfish and acrobrachium have been available for almost ten years, their popularity among farmers has been rather limited. No similar products for snakehead have yet been marketed. Failure of the local feed milling industry to develop products sufficiently acceptable to the aquaculture industry may be attributed to a general lack of reliable information concerning the nutritional requirements of the cultured species and how such requirements can be met, using ingredients the nutritional value of which remains largely undetermined for fish.
The result is the marketing of products that have been found to be less efficient and economical to use than traditional feeds, despite their convenience with regard to storage and handling. Nevertheless, development of efficient and economical commercial feeds, based on alternative feed resources, is desirable for three important reasons. These are: (a) rapid expansion of intensive aquaculture in the country; (b) increasing scarcity and rising cost of trash fish; and (c) need for feeds over which quality control measures can be more easily exercised. The success of such a development effort would require more precise knowledge concerning: (i) the nutrient requirements for growth of the respective species; and, (ii) the nutrient composition as well as feeding value of individual feed ingredients that are available and considered suitable for feeding fish.
