Fig. 3

Estimated levels of the digestive enzymes’ activity observed in the intestinal homogenate of the O. niloticus fed on 30 or 60 mg/kg BIO-ZnNPs compared to non-supplemented fish for 8 weeks. Data were represented as Mean ± SEM. Values with a different letter superscript are significantly different between groups (ANOVA with post hoc Tukey test, *P (<0.05), **P (<0.01). ***P (<0.001)