Aquatic feeds are traditionally based on fishmeal and soybean meal. Photo: Dreamstime

Dejan Miladinovic writes in that in recent years, the price hike for feed raw materials, in global and national markets, has resulted in an increased number of malnourished and hungry people. Even though the awareness of the general public and policy-makers has been increased, the fragility of the global food and feed system remains.

Optimally, an adult person needs to consume 60 g of protein per day. To feed enough protein to the world’s population by 2050, about 790 million tons of protein will be required. This number is 50% more than today’s production.

The global feed industry needs to start the feed-protein revolution to ensure that the world population will be able to have access to food in the future. This means that we have to move away from the so-called first generation feed sources.

Feed raw material sources can be defined through three generations. First generation feed is commercially available. However, it is in direct competition with human food supply and depends on vast resources of arable land, irrigation and fertilizers.

The second generation is less competitive with human food and not based on arable land and irrigation. Second generation feed sources are based on insects and microbes and its usage is challenging due to getting into new technologies and unknown demand.

A third generation of aqua feed source is recapturing nutrients from, for example, dairy and pig farms’ wastewater. Science is already developing technologies that can recover phosphorous and nitrogen from manure. These technologies are economically feasible, however markets are quite immature.

Aqua feed is a great example of where big steps can be made in the protein revolution. The feed-grade materials used in aquatic feeds are traditionally based on fishmeal and soybean meal. Globally, more than 80% of soybean produced is used for manufacturing animal feed. Fishmeal is manufactured by processing the wild catch, where problems such as overfishing remain.

About 25% of the world’s fish catches are used as animal feed. In the end, this is not a sustainable way of feeding farmed animals and a sustainable economy with the use of novel feed ingredients is therefore unavoidable.

Good examples of second generation feed sources are microalgae, yeast and bacterial biomass. These single cell organisms are proliferating much faster than any other biomass on the planet, with an excellent amino acid profile in their protein and with a high digestibility rate in the research model animals.

Microalgae are well known as immune boosters and strong sources of protein. The space required for growing microalgae is insignificant. Overall, microalgae do not require any arable land, or a freshwater supply. The harvest of microalgae can be year round.

The timeworn open pond systems are being replaced by new and more efficient systems like photobioreactors, flat panels and tubular systems. With such new systems, the production-optimization is exponentially increasing.

As well as protein, the microalgae contain valuable polyunsaturated fatty acids, which are a more sustainable source of valuable nutrients for the aquatic organisms than fish oil. Microalgae are rich sources of pigments, chlorophylls, carotenoids and phycobiliproteins. The inclusion of microalgae in diets for various fish and crustaceans has produced a pool of scientific evidence of a positive growth effect and increased intestinal functionality.

Due to the chemical composition of microalgae, they are a promising alternative for enhancing the nutritional value of conventional aquatic feeds, as a partial substitute for fishmeal for intensive aquaculture. The pool of scientific literature is suggesting that the inclusion rate of microalgae as high as 20% is recommended due to the positive effect observed on the functionality of the digestive systems in aquatic farmed species.

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