Page 29


recovery during mixing and extrusion), to estimating the quantitative requirement for various species (Florida pompano, California yellowtail, white seabass, sablefish) and evaluate any toxicity effect when feeding very high levels of taurine in the same species. Dr Salze acknowledged, “I also want to recognise the support of funding agencies, starting with the Soy in Aquaculture Alliance (SAA), who supported us for both research and meetings to facilitate discussions. The Auburn Agriculture Experimental Station and NOAA Sea Grant also funded a significant portion of this work. Finally, the institutions of all teams above contributed resources.”

Collaboration and project development

Talking about how the project came about, Dr Salze divulged, “I initiated the project by reviewing the literature for all current knowledge on the use of taurine in any species of fish. After that, it was critical to identify the knowledge gaps I mentioned. Filling them was necessary for a successful amendment petition to the AAFCO. For this, the help from FDA’s Center of Veterinary Medicine (CVM) and its now director, Dr Charlotte Conway, was instrumental. Their role is to review applications similar to the one we were preparing, so they provided invaluable counsel, in terms of both knowledge gap as well as the best application pathway to achieve our goal.” He continued, “All the collaborative work I mentioned was centralised by me at Auburn. My job was to crunch numbers on the research we all had conducted (with the help of corresponding team), and bring it all together in a single document with my co-authors (Drs. Gaylord, Johnson, and Davis) we could then put forward to the CVM and AAFCO.”

Length of project and future aims

Dr Salze expanded, “The issue of the absence of fish in the AAFCO’s taurine definition became clearly apparent in 2012. We obtained our initial grant to support the work that year, though the bulk of the research was conducted in 2013. It is particularly rewarding to see such a long-term project come to fruition. I think we are all looking forward to see the impact this will have on the American fish feed industry – I expect it to be quite significant. Even though our work is now complete with regard to the AAFCO taurine definition, there is still a lot of work to be done with taurine. In fact we are currently investigating the effect of taurine supplementation in broodstock spawning output and larval performances.”

Will there be a future application for the use of taurine?

He concluded, "With the amended definition, it has already become another arrow in the fish nutritionist’s quiver. We know it will help reducing our use of animal protein, especially fishmeal. After that, who knows? It is used in pet food, as an essential nutrient for cats, and now fish. It is included in infant formula, as well as in so-called energy drinks. Taurine is a small molecule involved in many, many physiological functions. I always say that taurine does everything for you, short of your laundry. This is precisely why the exact mechanism of action is so difficult to discern, since there are more than one, and they are all happening simultaneously in the body. Once we understand these mechanisms better, perhaps we will be able to give direction to these functions and promote the ever-important things to us aquaculturists: feed costs, growth, health, gamete quality, larval development, feed efficiency, etc. In one word (heck, for what it’s worth) sustainability.” International Aquafeed - July 2017 | 27

Jul 2017 - International Aquafeed magazine