Determination of optimal feeding rates for juvenile lake sturgeon (Acipenser fulvescens) juvenile fed with a formulated dry diet

Authors: YANG, S - University Of Wisconsin; ZHAI, S - University Of Wisconsin; Shepherd, Brian; BINKOWSKI, F - University Of Wisconsin; HUNG, S - University Of California, Davis; SEALEY, W - Us Fish And Wildlife Service; DENG, D - University Of Wisconsin

Submitted to: Aquaculture Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2019
Publication Date: 5/29/2019
Citation: Yang, S., Zhai, S., Shepherd, B.S., Binkowski, F.P., Hung, S.O., Sealey, W.M., Deng, D.F. 2019. Determination of optimal feeding rates for juvenile lake sturgeon (Acipenser fulvescens) juvenile fed with a formulated dry diet. Aquaculture Nutrition. 25 (6). https://doi.org/10.1111/anu.12932.
DOI: https://doi.org/10.1111/anu.12932

Interpretive Summary: Sturgeon products (flesh and roe) are among the highest value commodities in world-wide aquaculture. In the Great Lakes Region of the U.S., there is strong interest in developing capacity for commercial production of this species mainly for fisheries restocking efforts. Production is limited due to the lack of a cost-effective formulated diet and knowledge of required feeding rates for juvenile lake sturgeon. The aim of this work was to develop a semi-purified formulated dry diet, determine the optimal feeding rates and assess the effects of this diet on growth and biochemical composition of juvenile lake sturgeon (Acipenser fulvescens) with differing initial sizes (30 grams body weight and 80 grams body weight) during a three week trial. In both trials, growth and biochemical indices of juvenile sturgeon increased with dietary ration level. Based on growth rates, we calculated the optimal feeding rates to be 3.45% and 2.9% for fish of 36 grams and 80 grams in body weight, respectively. These findings show that juvenile sturgeon can be fed formulated dry feed and the estimated feeding rates can enable establishment of best management practices that facilitate maximum growth of juvenile lake sturgeon in production systems. Use of best feeding practices will improve production efficiency and contain feed costs for aquaculture producers.

Technical Abstract: Two three-week growth trials were performed to determine the optimum feeding rate (OFR) of juvenile lake sturgeon (Acipenser fulvescens) fed a semi-purified formulated diet based on evaluation of growth performance and effects on body composition. Fish with initial body weight of 36 g were fed with five feeding rates (0.5, 1, 2, 3, and 4% body weight per day; BW.d-1) for trial I, and fish of initial body weight of 80 g were fed three feeding rates for trial II (0.25, 0.5, 1, 2, and 3% BW.d-1) at 22 C with three replicate tanks per treatment. The fish were hand-fed three times daily and feed consumption observed. Final body weight, weight gain, hepatosomatic index, carcass somatic index, condition factor, energy and protein retention, feed conversion ratio and protein efficiency ratio were significantly affected by the different feeding rates (P < 0.05). The whole body lipid level increased, but moisture content decreased significantly with higher feeding rates. The ratio between total carbon and total nitrogen was shown to be positively responsive to the feeding rates and whole fish lipid content. The results also showed that suboptimal feeding rate significantly depressed protein synthesis based on the measurement of RNA/DNA ratio in white muscle. Based on the polynomial regression model analysis, the optimal feeding rate to support the maximum growth of 36 g and 80 g size of fish was estimated to be 3.45% and 2.90% BW.d-1, respectively. Based upon protein and energy retention measurements, optimal feeding rates for the two different sized fish were estimated to be 2.2-2.73% BW.d-1 and 1.68-1.99% BW.d-1, respectively.