Effects of yeast culture substituting fishmeal on growth, nonspecific immunity, intestinal, and hepatopancreatic histology of Litopenaeus vannamei

This study investigated the effects of yeast culture (YC) substituting fishmeal (FM) on growth, nonspecific immunity, intestinal and hepatopancreatic histology of Litopenaeus vannamei. Based on the control diet with an FM content of 200 g/kg, YC was used to decrease dietary FM to 200, 160, 120, and 80 g/kg (FM20, FM16, FM12, FM8), respectively. Then, the four diets were fed to shrimp (2.78 +/- 0.10 g) for 8 weeks. The results indicated that the FM8 group had poorer weight gain and higher feed conversion ratio than the control (p < .05), while the FM16 and FM12 groups showed no significant difference to the control (p > .05). Protein and lipid retention in the FM12 and FM8 groups were decreased (p < .05), and hepatopancreatic activities of superoxide dismutase and alkaline phosphatase were increased and malondialdehyde content was decreased in the FM12 group (p < .05). In the FM8 group, the crude protein digestibility, hepatopancreatic protease and amylase activity, the intestinal villi length and width were decreased (p < .05), and hepatic corpuscle was observed with atrophy and irregular lumen shape. In conclusion, YC can successfully replace 40 g/kg FM in a shrimp diet with FM inclusion of 200 g/kg.

Automated summary

This study found that yeast culture can successfully replace 40 g/kg fishmeal in a shrimp diet with 200 g/kg fishmeal inclusion. Shrimp fed diets with 160 and 120 g/kg fishmeal showed no significant differences in growth and immunity, while diets with 80 g/kg fishmeal had negative effects on shrimp.