March 26, 2009
India develops new technology to lower shrimp feed costs
Researchers at India''s School of Industrial Fisheries have developed a biofloc technology (BFT) that could lower the cost of shrimp feed.
The new technology converts accumulated pond bed waste into biofloc and keeps the carbon-nitrogen ratio at a favourable level even as inorganic nitrogen is immobolised into bacterial cells that later serve as shrimp feed.
BFP can reduce conventional shrimp feed''s protein content, which makes the feed costly, from 40 percent to 25 percent without compromising growth and production, the researchers said.
Fish feed waste on water-bodies is a major source in concern in marine aquaculture, particularly because aquaculture production has increased 45 percent since 2000.
Five types of locally available carbohydrates were screened as carbon sources for C:N ratio maintenance and among them tapioca was found to be the most efficient in shrimp farms, said Madhusoodana Kurup, director of the research group.
Farmers could benefit from the technology since 25 percent of diet with carbohydrate addition to the water column results in a 54-percent higher revenue per hectare.
The necessary dietary protein level of shrimp feed can be sharply reduced by adding carbohydrates to the water, which would lower costs and increase profits, the researchers said.
It may also help reduce the concentration of toxic products such as ammonia and nitrite, and reduce nitrogen discharge into open waters.
The research team has also developed a larviculture technology for the giant freshwater prawn using biofloc technology.
The development of biofloc technology is important in order to reduce the over-reliance on fishmeal produced from trash fish, of which the stock has decreased dramatically in the oceans, Kurup said.