Dietary fat content and feed supply influence growth and body composition in juvenile beluga sturgeon (Huso huso)

This study is to evaluate the impacts of two levels of fat on the fish growth, feed intake, and compositions of muscle, liver, and viscera on the juvenile Huso huso. There were four treatments: two experimental diets (high-fat: 30% and low-fat: 15%) and two feeding levels (100 or 60% of satiation). The treatments were assigned to 16 tanks each with 15 fish, with four replicates for each treatment. Beluga sturgeon juveniles with an initial weight of 61.3?±?4.4?g were reared for 3?months. Increasing fat content of the diets resulted in an increased final weight (621.8 vs. 467.5?g for high-fat and low-fat diets, respectively, at 100% feeding level; p?<?0.01), but had no impact on feed conversion rate (FCR; p?>?0.05). Total feed intake was increased by the use of high-fat diet (487.8 vs. 365.0?g for high-fat and low-fat diets, respectively, at 100% feeding level; p?<?0.01). Results also showed no interactions between fat level of the diets and feeding level in final weight and FCR. Beluga sturgeon muscle and liver fed high-fat diets contained higher fat than those fed low-fat diets (186.5 and 329.6 vs. 144.1 and 261.9?g?kg^?1 for high-fat and low-fat diets, respectively, at 100% feeding level; p?<?0.01), and feeding levels did not change protein content of the examined organs. In conclusion, beluga sturgeon shows an enhanced growth on high-fat diet, and feed intake does not reduce by the use of high-fat diets.