Nutritional challenges in white sturgeon aquaculture, particularly during the grow-out phase, have been linked to suboptimal commercial diets, often resulting in excessive visceral fat deposition and fatty ovaries. These issues suggest inefficiencies in nutrient partitioning, prompting the need for diet optimization. A 2×3 factorial experiment was conducted to evaluate the effects of varying dietary protein and lipid levels on growth performance, nutrient utilization, and mesenteric fat deposition in white sturgeon. Six experimental diets were formulated with two levels of dietary protein (40% and 45%) and three levels of dietary lipid (15%, 20%, and 25%).
A total of 264 one-year-old white sturgeon, with an average initial weight of 930.29 g ± 25.58 g, were randomly allocated to 12 tanks (1500L), with two replicates per diet (n=22 fish per tank) for 20 weeks. The fish were fed a 6mm pellet diet at 2% body weight per day, using a combination of hand feeding and automatic feeders. Individual fish were measured for weight and length every four weeks, and linear regression analysis was performed to model the relationship between time (weeks) and weight gain across dietary treatments.
After 16 weeks, fish fed diet of 45% protein and 25% lipid (45/25) exhibited the highest growth rate (71.64 g/week) and the lowest feed conversion ratio (FCR), while those fed a diet of 40% protein and 15% lipid (40/15) had the lowest growth rate (61.65 g/week). After the 20-week feeding trial, response surface methodology (RSM) will be employed to identify the optimal nutrient combinations that achieve at least 90% of the maximum growth response. These findings will help develop cost-effective diet formulations for white sturgeon farmers and feed producers. This study is funded by the USDA Western Regional Aquaculture Center.