FISH FEED

Since capture-based aquaculture was traditionally developed to even out the surplus from capture fisheries during the monsoon season, locally captured, low value fish constituted the basis for aquaculture feed, sometimes mixed with other on-farm products including rice bran.

The large yields of “trey riel” (Cirrhinus siamensis) and other low value species, constitute the basic feed for culture of both Pangasiid catfishes and snakeheads in Cambodia (Ngor, Aun and Hortle, 2005).
In the Nam Ngum Reservoir in Lao People’s Democratic Republic, the locally available small freshwater clupeid “Pa Keo” (Clupeichthys aesarnensis) is the main feed ingredient for the cage culture of snakehead (Hambrey, 2002).
Until recently, 95–97 percent of Vietnamese Pangasiid cage culture systems used home-made feeds (Phu and Hein, 2003). Food safety concerns, fluctuating quality, rising trash fish costs and the establishment and expansion of the fish food production industry in Viet Nam have encouraged farmers to increasingly use commercial pelleted feeds for monoculture grow-out of Pangasiid catfishes in cages and ponds. At present the division between home-made and manufactured feed is approximately 20:80. Pangasiid catfishes are also produced in small-scale integrated grow-out systems in polyculture with other species and fed with small marine and/or freshwater fish species which are either bycatch or targeted low-value species, as a supplementary feed (Edwards, Tuan and Allen, 2004).

Factoring in levels of trash fish in home-made diets and fishmeal content in pelleted feeds for Pangasiid catfishes, moisture content and FCR, Edwards, Tuan and Allen (2004) estimated that a minimum of 64 800 to a maximum of 180 000 tonnes of trash fish were used to produce the 180 000 tonnes of Pangasiid catfishes that Viet Nam produced in 2002.