For 2014, the last year accurate figures are available, Vietnam aquaculture produced an estimated 1.2 million tons of catfish, requiring an estimated 2.4 million tons of compound feed, traditionally produced from locally-available cassava.
However, the production of cassava in Vietnam has not kept pace with the growing demand for its use in aquaculture, swine and even the production of ethanol for use in fuels, resulting in both higher prices for cassava and shortages.
To test the viability of substituting sorghum or corn for cassava, the Council recently concluded in-country feeding trials, with support from the United Sorghum Checkoff Program, for Pangasius, a catfish species native to Southeast Asia that is sometimes called basa.
The trials were conducted at a private research farm in Vietnam and compared diets based on sorghum (20% inclusion rate), corn (10% inclusion rate) or cassava (15% inclusion rate).
The results of the trials reached the conclusion that both grains could efficiently and profitably be substituted for cassava as a source of starch for feeding Pangasius on Vietnamese catfish farms.
Results showed no difference between the sources of starch on growth performance, fillet colour or physical properties of feed pellets (density and floatability). Beyond starch, sorghum is also low in tannins and contains higher protein (more than 10% versus 2.5 percent) and amino acids (like corn) than cassava, particularly tryptophan and threonine.
The new data will bolster local efforts the Council is undertaking to promote corn and sorghum for new uses, like in aquaculture.
Both grains - sorghum and corn - can be used for feeding catfish, but limited research on doing so was previously unavailable, said Manuel Sanchez, USGC assistant director for South and Southeast Asia.
This report helps fill the gaps for more information about feeding sorghum and corn to Vietnamese catfish as a substitute for cassava.