Sweet potato eyed as new low-cost aquaculture feed

MANILA, Philippines - The government is funding a research on the use of protein-enriched sweet potato as a low-cost and high quality aquaculture feed.

Without specifying the total funding granted for the project, the Bureau of Agriculture Research (BAR) said it is supporting the study conducted by the Tarlac College of Agriculture (TCA) for the commercialization of the technology for the manufacture of an alternative aquaculture feed.

Sweet potato (Ipomoea batatas) locally known as kamote, is a food staple for poor families because it is easy to cultivate and costs less than a kilo of rice.

One of the problems facing the aquaculture industry today is the high cost of fish feed.

Nutritionists all over the world are constantly searching for alternative dietary protein sources of fish to maximize growth and increase production within the shortest possible time and at the lowest cost.

TCA’s project titled “Technology Commercialization of Protein-Enriched Sweet Potato as Feed for Aquaculture,” funded under the National Technology Commercialization Program (NTCP) of the BAR, aims to provide fishpond operators with an alternative feed formulation for aquaculture specifically for bangus, crabs and prawns.

Project proponents Dr. Rodolfo Domo-os, Dr. Ma. Teresa S.J. Valdez and Dr. Manuelo Agsaoay are collaborating with fishpond operators in Malolos, Bulacan; Balanga, Bataan; Dagupan, Pangasinan; and Iba, Zambales

Based on the studies conducted by TCA, the protein-enriched sweet potato is created through microbial fermentation. The researchers reported that the protein content of sweet potato pulp rose by 17 times from the original content after enrichment by fermentation.

Sweet potato chips are ground and fermented following the procedures employed in protein enrichment pulp.

The protein-rich feed is harvested after two weeks of fermentation, after which, it is sun-dried to remove the odorous metabolites.

After drying, the fermented protein-enriched sweet potato could remain fresh up to two years without adding anti-oxidants.

The researchers initially produced 16.8 tons of the feed to supply the requirements of the technology demonstration for bangus, tilapia, crabs and prawn aquaculture areas.

The technology developed by PCA is protected by a trademark for a period of 50 years.

The university will next establish a feedmill to mass-produce the product for distribution to the test areas.

Dr. Agsaoay said the cost of production of the feed is already “reasonable and can be mass produced at a village level through technology transfer agreement.” It costs P612.50 to produce every 50-kilo bag of the feed.

“With this technology, fisherfolk can now realize higher profitability compared with commercial feed utilization.  The cost and return analysis comparing PESP from that of commercial feed is comparable. Sustainability in the distribution of the product and sale of the product has been proven. Hence, the product is readily available in Tarlac, sweet potato being its flagship crop,” he said.