Growth, Body Composition, and Fatty Acids Changes in Siberian Sturgeon during Starvation and Refeeding; Effect of Different Macronutrients Levels

In this study, the effect of dietary macronutrient composition (two levels of protein 44% and 38% with two carbohydrate/fatty ratios of 1.4 and 3) was studied during starvation and re-feeding with the aim of achieving growth, body composition, and fatty acids in the body of Siberian Sturgeon (Acipenser baerii, Brandt, 1869). This experimental study was carried out at the International sturgeon research institute in a completely randomized design. 360 fish (with an initial weight of 30±5g) were randomly distributed in 24 tanks of 500 liters (15 fish per tank) with a volume of 350-400 liters capacity. Fish were fed on 4 different diets; protein 38% - carbohydrate: lipid ratio 3 (LP-St), protein 44% - carbohydrate: lipid ratio 3 (HP-St), protein 38% - carbohydrate: lipid ratio 1.4 (LP-L) and protein 44% - carbohydrate: lipid ratio 1.4 (HP-L), respectively. The fish were fed apparent satiation for 3 weeks, then, starved for two weeks, and, then, re-fed for 5 weeks. The results were analyzed, using SPSS 22 software by multivariate analysis of variance and Duncan's test. Findings: Compensatory growth did not occur in any treatments. In the control group, the best growth was observed in HP-L, while after re-feeding, HP-St represented the best weight gain and feed conversion ratio The dietary composition has a significant effect on the SFA, MUFA, and PUFA fatty acids, while the two weeks of starvation slightly increase only MUFA and have no significant effect on other fatty acids.