EVALUATION OF FISHMEAL-FREE, SOYBEAN MEAL-BASED DIETS IN HYBRID CATFISH Ictalurus punctatus x I.  furctatus

James Schwartz*, Waldemar Rossi Jr., James H. Tidwell and Vikas Kumar
 
 Aquaculture Research Center
 Kentucky State University
 Frankfort, KY 40601
 james.schwartz@kysu.edu

As one of the fastest-growing food industries in the world, aquaculture is rising quickly to meet the demand of the world's population of seafood consumers, while the market is in short supply of fishmeal and fish oil. Therefore the development and optimization of fish meal (FM)-free, growth-promoting and cost-effective aquafeeds is essential for the aquaculture industry to flouish. Foremost among the commercially available feedstuffs currently used as surrogates for FM in aquafeeds is soybean meal (SBM). Despite being economical and nutritious, with high protein and a balanced amino acid profile, conventional SBM contains anti-nutritional factors (ANFs) that can negatively affect growth and the physiological status of fish and, hence, limit its applicability as a feed ingredient. In order to increase SBM utilization in animal feeds, different processing technologies including solid-state fermentation and enzymatic treatment have been implemented to reduce or eliminate ANFs in conventional SBM and improve its nutritional value. However, there has been relatively little research done on comparative studies of differently processed SBM in diets for farmed fish. Therefore, our goal was to assess the nutritional value of four types of SBMs such as: I. Dehulled solvent extracted commodity SBM, II. Enzymatically treated SBM, III.  Bio-converted SBM and IV. Fermented SBM in the diets of hybrid catfish (HCF, Ictalurus punctatus x I. furcatus).  

Eight experimental diets were formulated to contain 35% crude protein, 7% lipid, and an estimated 2.9 kcal of digestible energy per gram.  These diets were designed to evaluate four types of commercially available SBMs (I-IV), each at two levels (0 and 10%) of dietary FM. Groups of 15 HCF (average initial weight of 8.2 g) were stocked into 24 ten-gallon tanks in a RAS system and are being fed (in triplicate) one of the randomly assigned diets twice daily to apparent satiation. Group weight was taken at the beginning, and will also be taken halfway through and at the end of the experiment.

At the end of experiment proximate composition, amino acid and fatty acid profiles of diets and fish carcasses will be analyzed. The growth performance, nutrient utilization parameters, muscle yield and physiological parameters including blood chemistry and protein metabolism enzymes activity will be evaluated. Resulting data will be presented. Based on the anticipated outcomes, among the four SBMs, one of them will provide an economical potential alternative ingredient for use in aquaculture diets. It will also provide safe, healthy and profitable seafood.