Vietnam produced an estimated 1.2 million tons of catfish in 2014, requiring an estimated 2.4 million tons of compound feed, traditionally sourced from locally-available cassava. However, the demand for cassava for aquaculture, swine and even fuel ethanol production has risen significantly while domestic production has not increased in the last five years, leading to concerns about supply and price.
“Fish is the one of the most affordable protein sources in the Southeast Asia region,” said Manuel Sanchez, USGC assistant director for South and Southeast Asia. “Aquaculture is a key sector primed for potential import growth, providing U.S. feed grains a substantial market opportunity.”
To test the viability of substituting sorghum or corn for cassava, the Council recently concluded in-country feeding trials for Pangasius, a medium-large to very large catfish species native to Southeast Asia that is also called basa fish or bocourti.
The trials were conducted at a private research farm in Vietnam and compared diets based on sorghum (20 percent inclusion rate), corn (10 percent inclusion rate) or cassava (15 percent inclusion rate). They concluded both grains could replace cassava as a source of starch for feeding Pangasius.
Results showed no difference between the sources of starch on growth performance, fillet color or physical properties of feed pellets (density and floatability). Beyond starch, sorghum is also low in tannins and contains higher protein (more than 10 percent versus 2.5 percent) and amino acids (similar to 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 is available,” Sanchez said. “This report helps fill a need for information about feeding sorghum and corn to Vietnamese catfish as a substitute for cassava.”