“Fish-Free” feed for largemouth bass is feasible and economically viable
The print version (Aqua Culture Asia Pacific, Issue May/June 2022) published a F3 press release on a new study by McLean et al (2022) in Aquaculture Research where fishmeal, fish oil-free feeds deliver excellent growth, survival, feed conversion and fillet quality. Total replacement of fishmeal and fish oil in largemouth bass feed is both feasible and economically viable. The fish fed experimental feeds without fishmeal or fish oil also had higher DHA-to-EPA ratios than those fed commercial feeds, with algae oil having the highest ratio. Consumers ultimately benefit from these higher amounts of heart and brain healthy DHA and EPA from eating the fish.
The vast majority of the farm-raised largemouth bass is farmed and consumed in China—an estimated 432,000 tonnes in 2018 according to the China Fishery Statistics Yearbook. As the world’s largest producer of farmed fish, China is working toward more sustainable farming practices nationwide. Largemouth bass, which is native to North America, was first introduced into mainland China in 1983 and today is a major freshwater aquaculture product throughout the county. “This will also come as good news for fish farmers in China at a time when consumers are shifting their appetites toward high-value species like largemouth bass that consume large amounts of fishmeal and fish oil,” said Ewen McLean, lead author of the study and principal at Aqua Cognoscent. “Switching to locally sourced, and often cheaper feed ingredients could help put more money in the pockets of fish farmers.”
The price of fishmeal has increased 3.4-fold over the last 20 years, and the present-day cost is around USD1429/tonne. On the other hand, the price for soybean meal, an often-used substitute for fishmeal in aquafeeds, has risen 2.8-fold over the same timeframe and is roughly half the price according to Index Mundi. Alternatives to fish oil, such as soybean and canola oils are on average less expensive as well.
During the 10-week feeding trial conducted in a recirculating aquaculture system at Texas A&M, McLean and colleagues compared weight gain, survival rates, feed conversion ratio and fillet quality of fish fed fishmeal, fish-oil free experimental diets against two commercial feeds (Huifu, Xinxin Tian’en Company, Zhejiang Province, PR China and Alltech Coppens, Leende, The Netherlands), specifically designed for juvenile largemouth bass (Micropterus salmoides).
The fishmeal component of experimental diets was replaced using poultry by-product meal and soy protein concentrate. One experimental diet contained fish oil whereas in others, fish oil was replaced with canola, flax and/or algal oil or combinations thereof.
At the end of the trial all fish fed the experimental fishmeal and fish-oil free diets had similar weight gain and survival rates matching those fed the Xinxin commercial feed. The Coppens commercial feed had the lowest growth and survival rates. The experimental diets also had excellent feed conversion ratios.
According to a 2018 study in Nature Sustainability if current use of fishmeal and fish oil by the animal feed sectors remain the same, forage fish populations will be overextended by 2050, or before. Commercially valuable species such as salmon, cod and tuna, as well as marine mammals and seabirds depend on forage fish in the wild. Since over 50 percent of seafood is farmed, the variety of seafood on consumers’ plates could shrink without innovation in “fish-free” feeds, since they rely on wildcaught resources.
This study is a step towards removing the supply chain bottlenecks by testing more available and sustainable ingredients that will make seafood available into the future.
The study was supported by the F3 – Future of Fish Feed’s Feed Innovation Network. The F3 – Future of Fish Feed is a collaborative effort between NGOs, academic institutions, and private partnerships to accelerate the commercialisation of innovative, substitute aquaculture feed ingredients to replace wild-caught fish. It is available as open access. https://f3fin.org
McLean, E., Alfrey, K. B., Gatlin, D. M., & Barrows, F. T. (2022). Responses of largemouth bass (Micropterus salmoides, Lacépède, 1802) to fishmeal-, and fish oilfree diets. Aquaculture Research, 00, 1– 12. https://doi.org/10.1111/are.15815
Reference
Froehlich, H.E., Jacobsen, N.S., Essington, T.E. et al. Avoiding the ecological limits of forage fish for fed aquaculture. Nat Sustain 1, 298–303 (2018). https://doi.org/10.1038/s41893-018-0077-1
F3 Challenge – Carnivore Edition
In September 2019, F3 launched a contest F3 Challenge – Carnivore Edition. At the halfway point, in May 2022, it reported that contestants have sold a combined total of over 3,141 tonnes of fish-free feed at the halfway point in the sales contest, which is designed to spark innovation in the aquafeed industry to find viable, cost-competitive replacements to fishmeal and fish oil in aquaculture feed.
Dainichi Corporation takes the lead in the Other Carnivorous Species Category for its “fish-free” feed for red sea bream. The contestant teams Star Milling Co./ The Scoular Company (salmonid category) and Empagran/Veramaris (shrimp category) maintain their leads in their respective categories.
An estimated 84.6 million forage fish have been saved from being fish food since contestants began reporting sales, according to the F3 Feed Innovation Network’s forage fish savings calculator.
The goal of the F3 – Future of Fish Feed is to assure greater global food security by reducing the aquaculture industry’s reliance on fishmeal and fish oil derived from small forage fish such as menhaden and sardines and to future-proof it against shocks to the supply chain.
The award is USD100,000 in each of three categories—salmonid, shrimp, and other carnivorous species. The F3 Challenge is a sales competition to award prize monies to the contestants that produce and sell the most “fish-free feed” within their designated category.
Eight qualifying F3 feeds were submitted by the six contestants competing toward the USD300,000 in prizes. Contestants began recording sales as of Oct. 1, 2020 or after submitting their feed. The qualifying F3 feeds for all prize categories must not contain any ingredients consisting of or derived from marine animals, including but not limited to: fish, squid, shrimp, or krill.
Reliance on wild-caught resources threatens the ability to grow many aquacultured species because the supply of small fish fluctuates globally and without any changes in technology, are slated to reach ecological limits by 2037. Reliance on wild-caught resources also threatens wild-caught commercial fisheries, such as tuna, salmon and cod, since these larger fish depend on smaller fish for their sustenance. Since aquacultured and wild-caught seafood comprises the entire supply of seafood, finding nutritionally equivalent alternatives to small fish is important for maintaining the supply of seafood globally.
All sales reported by companies remain unverified. F3 Challenge judges will verify F3 feed sales prior to announcing the winners per the contest rules.
Sponsors of the F3 Challenge include the University of Arizona, The Campbell Foundation, Synbiobeta, The Nature Conservancy, University of Massachusetts-Boston, Anthropocene Institute, Dawson Family Fund, Sustainable Ocean Alliance, Tides Foundation, Cuna Del Mar, the National Renderers Association and Shanghai Jiao Tong University.
The next rep0rting will be in July 2022.
