Morgan Cheatham and Tom D’Alfonso, USSEC

Aquaculture accounts for more than 50% of total global seafood production volumes, and aquaculture production volumes are increasing at a rate of 3.3% globally _¹. Meanwhile, capture fisheries volumes have remained relatively constant for decades, and have declined slightly in recent years. Demand for seafood products will continue to increase with the increasing global population _{^{1; 2}}. By 2050, global demand for protein will increase by 20%, leading to a corresponding rise in demand for seafood. The FAO predicts that aquaculture production volumes will reach 140 Million MT by 2050, which means that aqua feed production volumes will also minimally double during this time _¹. The aquaculture industry will have to find alternative protein sources for feed production to achieve this growth level sustainably _³. Soy products are well positioned to play a crucial role in this effort _⁴.

Transitioning to Sustainable Feed Sources

Moving away from a reliance on marine-derived ingredients has been a priority for the aquaculture industry for decades. Plant proteins are already the most used ingredients in aquafeed production globally _⁵. Soy has been a key ingredient used to replace marine ingredients in aquaculture, and its use has played a critical role in the aquaculture industry’s rapid expansion over the past two decades. Soy is a highly digestible protein source for aquatic species and presents advantages throughout the supply chain to ingredient purchasers, feed millers, and fish producers _⁶.   

The Advantages of Soy in Aquafeed

Using quality protein sources in aquafeed formulation is critical for the performance and, ultimately, cost efficiency of feeds. Access to a consistent, non-seasonal supply of one protein source benefits a feed miller who will not have to modify formulations regularly to account for variability in ingredient availability. Using soybean meal with consistent protein, amino acid content, and digestibility reduces or sometimes eliminates the need for safety margin use in feed formulation _⁷. Undamaged soybeans of consistent quality before crushing provide this advantage. This consistency reduces the cost of feed production, which is a savings that the owner can then pass down to the end user. Soybean meal is also easily stored in bulk at the feed mill, eliminating the need for multiple ingredient storage containers and increasing feed mill organization and efficiency _⁸. It is also a commonly and easily shipped cargo.

Nutritional and Operational Benefits

Soy is a protein-rich, low-cost feed ingredient suitable for inclusion in the diets of many aquatic species _⁶. The amino acid profile of soy protein products matches that of many finfish and crustacean species, and these amino acids are highly digestible and available to the fish. The benefits of soy extend beyond protein and amino digestibility to energy content. An example is the sucrose levels of U.S. Soy, which are significantly higher than soy of other origins. The increased energy content can be of greatly benefit fish with high metabolic demands.

Enhancing Sustainability with Soy

Improved environmental sustainability is yet another benefit of soy utilization in aquaculture. U.S. soybean yields have increased by over 90% per hectare since 1980 _⁴. This yield increase has improved land use efficiency and eliminated the need to convert virgin land into cropland in the U.S. This differentiates U.S. Soy from soy of other origins, and is an increasingly important consideration for those purchasing soy products. Soybean farmers in the U.S. committed to reducing land use impact, soil erosion, and greenhouse gas emissions to reduce the environmental impact of soy production even further _⁴. It is crucial to note that soybean meals produced from undamaged beans of consistent quality eliminate the need to use safety margins in feed formulations. Thereby allowing for higher volumes of animal and aqua feeds to be produced (and, in turn, animal protein) with the same gross quantity of soybeans, perhaps the most significant sustainability benefit of U.S. Soy to businesses.

The Future of Soy in Aquafeed

In addition to the inclusion of soybean meal in aquafeed formulations, the inclusion of value-added soy products also shows promise in the aquaculture space. Fermented soy and soy protein concentrate are exciting ingredients with the potential for broad application in aquaculture _⁹. The microbial fermentation process reduces soy’s antinutritional factors and increases nitrogen and phosphorous availability, thus producing a feed ingredient of high digestible protein content. This digestibility helps to overcome some of the challenges faced when feeding carnivorous species plant-based ingredients and may allow for the replacement of higher-cost ingredients.  White soy flakes undergo aqueous alcohol extraction to produce soy protein concentrate (SPC) and then may undergo thermal processing to produce low-antigen SPC.  SPC has a protein content similar to many fishmeals (65-67%) used in aquafeed production and has a comparable amino acid profile. These characteristics make SPC a suitable ingredient, and lower-cost alternative to fishmeal, in marine fish or fingerling feeds _⁹.

Reducing dependance on marine-derived ingredients using scalable solutions is critical for the expansion and improved sustainability of aquaculture globally. The inclusion of soy products in aquafeeds has already played a crucial role in the exponential growth of the aquaculture industry over the previous two decades. Soy will continue to play an essential role in the industry’s efforts to sustainably meet growing protein demand due to economic, biological, and sustainability benefits. The future of soy in aquaculture lies in the continued inclusion of soybean meal in feed formulations and the development and application of value-added soy products such as fermented soybean meal, soy protein concentrate, and others.

###

This article was first published in Aquafeed: Advances in Processing &
Formulation Vol 16 Issue 2 2024.

Citations: