Dr. Ron Johnson and scientists of the Aquaculture Program at the Northwest Fisheries Science Center (NWFSC) are currently searching for promising alternative feed ingredients to replace fish meal and fish oil in aquaculture feeds. The use of terrestrial plants, such as soybeans, can replace much of the fish meal in aquaculture feeds, but there are many nutrient deficiencies associated with these ingredients, such as taurine that is absent from plants. Dr. Johnson is nominated for the Technology Transfer Award for studies he conducted that determined taurine requirements for marine fish. This work led to FDA approval of taurine as a fish feed ingredient. This is a major accomplishment of the NOAA-USDA Alternative Feeds Initiative which identified determining taurine requirements in marine fish as a high priority in 2011 (see http://www.nmfs.noaa.gov/aquaculture/docs/feeds/the_future_of_aquafeeds_final.pdf). The use of taurine supplemented fish feeds in the U.S. benefits several sectors of the economy: fish growers, fish feed companies, soy industries, and consumers. Globally, taurine approval will facilitate the transition of marine based fish feeds to more sustainable fish based feeds. By doing this, aquaculture producers will lower fish in: fish out ratios of their operation and ultimately, aquaculture could become a net producer of fish protein.
This is a significant contribution to growth and economic viability of the aquaculture industry for the following reasons. Aquaculture is the fastest growing food-producing sector in the world today, and demands for feed ingredients, especially fish meal and oil, have increased dramatically in recent years. World industrial fisheries of feed grade pelagic species are currently managed at or near maximum yield, and harvests cannot increase in the future without severe ecological impacts. Furthermore, fish meal is the most costly ingredient in fish feeds for carnivorous fish and prices have tripled since 2002 ($600 to $1800/ton) while at the same time soy prices doubled ($200 to $400/ton). There is a need to replace fish meal and fish oil in aquaculture feeds if further growth of the industry is to be sustained.
Taurine, an amino sulphonic acid, has important roles in many critical physiological processes in all vertebrate animals. While taurine is ubiquitous in animal proteins, it is absent from terrestrial plant proteins commonly used in alternative fish feeds. Though many animals biosynthesize taurine, felines and some marine finfish have limited ability to produce taurine. In cats, a diet devoid of taurine will cause blindness and multiple birth defects. Taurine is allowed in cat, dog, and chicken feeds in the United States and is generally recognized as safe for humans. Taurine is a key ingredient in many energy drinks for human consumption.
There is a need to supplement alternative plant based fish feeds with taurine for optimal growth, nutrient retention, and overall health of many farmed marine fish species. However, until recently, taurine was prohibited in fish feeds in the United States because of the lack of evidence for its requirement. Through a series of experiments at the NWFSC, aquaculture program scientists led by Dr. Johnson demonstrated that taurine was beneficial and safe in alternative plant-based feeds for sablefish Anoplopoma fimbria, a model cold water marine fish. These studies also showed that human consumption of sablefish that received taurine-supplemented feeds would result in a low to moderate exposure to taurine, with minimal human health risks. Consumption of a typical 100 gram serving of a fillet from sablefish fed a taurine supplemented feed would equate to less than 6% of the total permissible daily allowance for taurine.
In early 2016, NWFSC Aquaculture Program Manager Ron Johnson joined scientists from Auburn University and the USFWS to petition the FDA to allow taurine as an ingredient in fish feeds. The petition was reviewed by scientists of the American Association of Feed Control Officers (AAFCO), a voluntary organization of local, state, and federal agencies and universities that collaborate with the FDA. After review, at the AAFCO 2017 mid-year meeting AAFCO accepted the petition recommendations and a new ingredient definition was adopted for taurine, allowing use of the nutrient in fish feeds (in addition to cat, dog, and chicken feeds). From the AAFCO ruling, taurine is now approved for use in fish feeds in the United States and U.S. feed manufacturers are now allowed to sell taurine-supplemented feeds internationally. It is anticipated the approval will facilitate the use of domestic crops (e.g. soybeans) in alternative fish feeds and further increase the environmental sustainability and economic potential of the aquaculture industry. Industry partners from the Soy Aquaculture Alliance (Indianapolis, IN) and Zeigler Feeds (Gardners, PA) congratulated Dr. Johnson and other petitioners in a formal letter, and stated that they believe taurine approval will greatly facilitate the use of U.S. soybean products in aquaculture feeds worldwide, which will reduce reliance on costly fish meal and oil as feed ingredients. Prior to this ruling, taurine supplemented fish feeds were approved for use in other countries such as Europe and Canada for many years and U.S. fish farmers have been at a competitive disadvantage at not having an option to use less costly plant-based feeds.
The use of fish feeds containing plant-based components supplemented with taurine is expected to reduce feed costs for U.S. farmers by at least 20%. Thus the economic benefits to the U.S. include: fish growers with the availability of less costly feeds, fish feed industries with expansion of international sales, soy farmers with increased use of their products in fish feeds, and consumers with reduced costs of farmed fish products. For example, in 2015, five million metric tons of U.S. produced soy beans were used in aquaculture feeds, which is $2 billion dollars at current prices. The approval for use of taurine as a supplement will substantially expand that market, resulting in many millions of dollars increases in the economy of soy beans for aquafeeds.
The research that Ron’s group conducted has been published in peer-reviewed literature, and provided the scientific basis for the recommendation.
Johnson, R.B., S.-K. Kim, A.M. Watson, F.T. Barrows, E.L. Kroeger, P.M. Nicklason, G.W. Goetz, A.R. Place. 2015. Effect of dietary taurine supplementation on growth, feed efficiency, and nutrient composition of juvenile sablefish (Anoplopoma fimbria) fed plant based feeds. Aquaculture 445, 79-85.