Nutritious pond feed yields more protein with lower quality feed

Researchers found that a feed that not only targets fish but also the pond organisms can help break down waste and produce natural feed for the fish.

Nutritious pond feed yields more protein with lower quality feed
July 15, 2021

Wageningen University developed the innovative concept of nutritious pond feeds and partnered with WorldFish to study locally available ingredients for use in feeds. The research was based in Bangladesh, China, Costa Rica, Egypt, France, India, Indonesia, Malaysia, the Netherlands, Vietnam and Zambia, in cooperation with small-scale farmers and commercial feed companies Aller Aqua Zambia, Royal de Heus Asia and Skretting Egypt.

The project aimed to develop nutritious pond feeds for tilapia that increase farm productivity and profitability, enhance natural food production in the pond, and pollute less; identify locally available ingredients for inclusion in pelleted fish feeds; and create tools to integrate the knowledge of locally available feed ingredients in nutritious pond feeds and disseminate them to fish farmers.

Commercially produced feeds are formulated to meet the nutrient requirements of the farmed species but also lead to nutrient-rich fish wastes that, when released, contribute to pollution in water bodies. Nutritious pond feeds, in contrast, nourish both the farmed species and other pond organisms, like bacteria, plankton and protozoa, to stimulate the pond’s inherent capacity to break down fish wastes and produce natural foods for fish.

The new feed used in the study contains more carbohydrates that are only partially digested by fish. Bacteria in the pond convert what is not digested into nutrients for the pond, contributing to the production of natural food for fish through the pond's food web.

As different ingredients are used, nutritious pond feed is cheaper than conventional feed and is of less direct nutritive value to the fish. The difference is compensated by the fact that the pond provides more high-quality feed. “This makes it very attractive for a fish farmer,” according to researcher Marc Verdegem. “Fish production is the same, if not higher, and the fish farmer pays less for the feed.” In Bangladesh, for example, fish farmers saw their income increase by 22%.

Aquaculture has developed rapidly and intensified in recent years, resulting in overfed ponds and a disturbed natural pond ecosystem. Verdegem said, “we studied how we can achieve a food web that ensures the pond stays healthy and functions as it should. Natural products such as pond organisms and plankton can contribute considerably to the fish's menu.”

Check out the study here.