Better ways to raise catfish by genome mapping, feed efficiency

Catfish farmers hope that research at Auburn University makes the state’s haul of catfish bigger, healthier and cheaper than ever before.

Zhanjiang Liu, an AU alumni professor in the department of fisheries and allied aquacultures — the science of raising water-based animals in a controlled environment — and his research team are hoping to breed catfish that grow bigger on less food, and that are more disease resistant than current catfish.

To do that, the team is going back to the basics — mapping the genome (the complete genetic makeup) of the catfish.

Liu, who has won one of Auburn University’s two creative research and scholarship awards, said it took $6 billion for scientists to map the human genome, but that only a few million dollars have been spent worldwide to map the catfish genome, according to AU Report, a university publication.

Mitt Walker with the Alabama Catfish Producers, a division of Alabama Farmers Federation, said a major focus of the research is being able to produce fish more cost effectively.

“The largest cost is feed cost,” he said. “Food cost is going to be extremely high this year … it is tied to a more national picture.

“The demand for corn and soy beans is up really high right now — those are two of the main components of catfish feed. And when the demand is higher, the cost is higher.”

Alabama has about 25,000 water acres of fish farms where nearly 250 commercial farmers produce 25 different aquatic species, according to the Alabama Catfish Producers. Farm-raised catfish is by far the dominant species, with Alabama ranking second in the U.S. in annual catfish sales.

During the past 20 years, production has grown by 1,600 percent, and Alabama still has the land and water resources to support an industry 10 times its current size.

Liu and his AU team have been working for 12 years on the genome project and have developed thousands of DNA markers that are being used to construct the genome map, according to AU Report.

Dennis Herndon, who lives in Eutaw, but has a catfish farm in Boligee, said Liu’s research certainly would benefit the catfish farmer first, and “you’d be able to produce cheaper and help the consumer, too.

“We do need a breakthrough, and we hope it would come on feed conversion,” he said.

At this time, it takes 2.2 pounds to 2.4 pounds of food to produce a pound of catfish. Chickens, he added, get a pound for almost half that.

“If we could get on that level, we could purchase at 20 to 30 percent cheaper than what we do now,” Herndon said. “The feed efficiency is what we need, as far as the taste of the fish.”