GOSSYPOL FREE COTTONSEED PROTEIN PROVIDES AN OPPORTUNITY TO ENHANCE THE SUSTAINABILITY OF AQUACULTURE BY REPLACING FISH MEAL - A REVIEW

Tom Wedegaertner*
 
Cotton Incorporated
6399 Weston Parkway
Cary, NC 27513
919-678-2271
twedegaertner@cottoninc.com

Many plants that exist on the planet today are here because they have evolved a chemical defense mechanism. Cotton is one such plant, which contains the antinutritional factor "gossypol". Gossypol is a cumulative toxin that can be detrimental to some animals who consume high levels of cottonseed protein over a long period of time. This has greatly reduced the utilization of this massive protein source, which is a natural by-product of cotton production.

Many different approaches to mitigate this toxin have been investigated. While there are physical and chemical methods to reduce the toxicity of gossypol, it seems that genetic removal of gossypol is the simplest and most effective solution.

Over the past several decades, there have been many research projects conducted to determine the maximum level of gossypol that can be tolerated by various aquaculture species. It has been known for some time that catfish and shrimp can tolerate much higher levels of gossypol in their diet than some other species. Shrimp are also fairly tolerant.

There is a renewed interest in cottonseed protein due to the recent biotechnology breakthrough that offers promise that gossypol can be almost eliminated in cottonseed protein by using current, safe, and effective plant biotechnology techniques. This technology could potentially eliminate gossypol as a concern and make available more than 10 million metric tons of cottonseed protein worldwide.

In anticipation of the huge volume of high-quality protein becoming available over the next several years, extensive research is underway to investigate its use in aquaculture feeds. Cottonseed protein flour has been recently evaluated in diets fed to shrimp, pompano, black sea bass, hybrid striped bass, flounder, and trout. Almost without exception cottonseed protein has replaced most or all of the fish meal in the diet. The replacement of marine proteins with terrestrial plant proteins dramatically improves the sustainability of aquaculture. It has been recognized for some time that cottonseed protein contains an "unidentified feeding stimulant," so palatability doesn't seem to be an issue with most species. This is not true for many other plant-based proteins. This presentation will review all the research to date on the utilization of cottonseed protein in aquaculture feeds.