Moderate dietary saccharicterpenin supplement ameliorates growth performance, muscle antioxidant capacity and quality of Procambarus clarkii

A 6-week feeding trial was conducted to evaluate the effect of different saccharicterpenin supplemental levels (0, 0.1, 0.3, 0.6, 1.2 and 2.4 g/kg, named S0, S0.1, S0.3, S0.6, S1.2, S2.4, respectively) on growth performance, muscle antioxidant and quality of crayfish ( Procambarus clarkii ). The results showed that S0.6 showed significant increase in weight gain rate (WGR), specific growth rate (SGR) and significant decrease in feed conversion ratio (FCR) ( P < 0.05). Compared with the S0, S1.2 showed significant increase in feed-meat ratio (FMR). Antioxidant enzyme activities were higher in crayfish muscle in S1.2 compared to other groups ( P < 0.05). Nutritional indices of meat quality showed that saccharicterpenin increased fat and decreased water of the muscle. Compared with the S0, total amino acids, essential amino acids were significantly higher in S2.4 and polyunsaturated fatty acids, docosahexaenoic acid, eicosapentaenoic acid were significantly higher in S1.2 ( P < 0.05). Dietary saccharicterpenin supplemental could reduce muscle brightness since muscle in S2.4 group possessed a higher degree value of yellowness, while S1.2 group had significantly lower redness value. Muscle springiness was significantly lower in S0.3 and S2.4 compared to the other groups ( P < 0.05). Additionally, the cooking loss was significantly lower in S1.2 ( P < 0.05). The muscle fiber diameter was significantly higher in S0.6, S1.2, S2.4 than in the S0 group, and the frequency of coarse muscle fibers was significantly higher in S1.2 and S2.4 ( P < 0.05). Both muscle growth and atrophy genes were upregulated in S1.2 and S2.4. Based on the quadratic regression analysis of FBW, WGR, SGR, FMR with saccharicterpenin supplement, the best growth performance and economic benefits of crayfish were achieved with the addition of 1.3–1.4 g/kg saccharicterpenin to the diet. Higher saccharicterpenin supplement may moderately increase the nutritional value but with the loss of appearance and taste. • Optimal saccharicterpenin (1.3–1.4 g/kg) maximizes crayfish growth (WGR, SGR) and feed efficiency (FCR). • Saccharicterpenin (1.2 g/kg) significantly boosts muscle antioxidant enzymes (SOD, GR, GST) activity. • Saccharicterpenin enhances muscle nutritional value (EAA, PUFA, DHA, EPA) and myofiber diameter.