CLAM PROCESSING COPRODUCTS AS AQUAFEED INGREDIENTS

While fish meal and fish oil represent the nutritional 'gold standard' of feed ingredients in many aquaculture diets, the research community has continued to explore reduced fish meal diets and fish meal alternatives.  Given that feed costs are commonly the major variable cost in aquaculture production, there is strong justification to continue to reduce the reliance on not only fish meal as a feed ingredient, but also to further reduce the cost of feed through the identification of suitable alternatives.  

In an effort to find  viable alternatives to fish meal, we are working with a corporate partner to evaluate the utilization of seafood processing waste streams, and their potential as fish feed ingredients.  We have analyzed the nutritional profiles of the handful of unique byproduct streams ,  have identified which byproduct streams are promising as aquaculture feed ingredients, and derived limited quantities of a dried meal using these clam processing coproducts .  

Beginning in 2017 experimental  feeds were manufactured, containing  either  differing levels of clam processing coproducts as attractants or control diets absent of clam processing coproducts .  T wo  trials have been completed with  these original formulations being fed to populations of hybrid striped bass and barramundi.  Initial results indicate that these diets are readily accepted by both species, and adverse effects attributable to clam-processing coproducts were not observed .   A recently completed third trial with re-formulated diets  including a diet containing clam processing coproducts at a 10x (CM10%) safety factor  has shown that growth, feed conversion and feed intake did not differ between the positive control (FISH) and recommended inclusion rate (CM1%) .  CM10% demonstrated higher average growth and feed intake than FISH but these differences were no t significant.  S urvival did not differ among  all treatments (p = 0.124). All liver tissue subjected to histological examination were considered non-pathological across all four diets.