Earthworms and yam beans: feeding fish in the future

Aquaculture is the world’s fastest growing food production industry, with farms supplying around half of the global fish supply. But to satisfy our soaring appetite for aquatic food, we first have to be able to feed the fish and shellfish. This isn’t such an easy task, as conventional feeds are becoming less sustainable and available. It’s no wonder then that the “Animal feeding and nutrition” Thematic Session was unofficially re-named “the fish and aquaculture” session, as all three presenters shined a spotlight on innovative aquaculture feed sources that are nutritious, but that can also address the challenges and demands of intensified fish and prawn farming. So what’s on the plate? Farmed Nile Tilapia, Cairo, Egypt. Photo by Samuel Stacey, 2012. The search for affordable, high-protein feed for fish gave rise to two very different proposals from our speakers. Johnny Ogunji from Ebonyi State University in Nigeria has been looking at African yam bean, a tropical legume seed local to central and western Africa, to replace soybean feed for catfish. His team has experimented with fermenting and boiling the yam bean to improve its protein content and amino acid composition, all in the attempt to ensure better catfish growth and health. Johannes Pucher, on the other hand, has turned to farmed earthworms as a potential solution. His research group from the University of Hohenheim in Germany is concerned that conventional fishmeal is inaccessible to farmers raising the low-value fish that are important for food security. Their earthworm trials on Nile Tilapia found promising results with protein digestibility and essential amino acids. Because these alternative feeds are quite novel, the discussions were very engaging, as presenters and participants critically debated how feasible each would be. What impressed me most was that some of the questions came from non-aquatic animal scientists. They may have been out of their depth in the world of fish and prawn science, but they were concerned with the same types of questions that matter in their own field: whether these proposals would be cost-effective and accepted by the farmers.


Post new comment

The content of this field is kept private and will not be shown publicly.
This question is for testing whether you are a human visitor and to prevent automated spam submissions.
Enter the characters shown in the image.