Dietary supplementation with Schizochytrium Limacinum in a plant protein-based diet on growth performance, flesh quality, myofiber development, and antioxidant profile of Litopenaeus vannamei

This research aimed to evaluate the effect of supplementing Schizochytrium Limacinum (S. Limacinum) to a plant protein-based diet on growth performance, flesh quality, myofiber development, and expression of antioxidant-related genes in Litopenaeus vannamei (L. vannamei). Shrimp (initial body weight: 0.25 ± 0.00 g) were fed three isonitrogenous and iso-lipidic diets (HF, 25 % fish meal (FM); LF, SPC and CPC replaced 60 % FM; LFD, LF diet supplemented with 0.8 % S. Limacinum) for 8 weeks. The results showed that the weight gain rate, specific growth rate, and final weight of shrimp were significantly increased in the LFD group compared to the LF group (P < 0.05). In addition, intestinal protein synthesis-related genes (target of rapamycin, tor; eukaryotic translation initiation factor 4E-binding protein, 4ebp; eukaryotic translation initiation factor, eif3k; ribosome protein S6 kinae, s6k1; raptor) were significantly upregulated in shrimp fed the LFD diet compared to shrimp fed the LF diet (P < 0.05). Muscle flesh quality (hardness, chewiness, and gumminess) of shrimp fed the LFD diet were significantly improved compared to those fed the LF diet (P < 0.05). Moreover, the expression of myofiber development and antioxidant-related genes (smych5, smych15, sod, gpx) were significantly higher in shrimp fed the LFD diet than those fed the LF diet (P < 0.05). In conclusion, supplementation of 0.8 % S. Limacinum in a plant protein-based diet improved the growth performance of shrimp, as well as promoted the flesh quality, myofiber development and the anti-oxidative ability of shrimp.