Nile tilapia fed insect meal: Growth and innate immune response in different times under lipopolysaccharide challenge

Abstract

Insects have been the subject of recent attention as a nutritious source and nutraceutical potential. Hence, we studied the effects of diets containing superworm larvae (Zophobas morio) meal on growth performance and innate immunity of Nile tilapia (Oreochromis niloticus). During 12 weeks, fish were fed with diets containing 0, 15% and 30% of superworm larvae meal (SWM) and then challenged with lipopolysaccharide (LPS). Cellular counts, lysozyme and complement system activity (HACS) were recorded over 0, 3, 6 and 9 hr post-challenge. The results revealed that dietary inclusion of SWM had no negative effects on growth performance of tilapia (p < .05). The moisture and lipid content increased (p < .05) in fish fed 30% SWM while ash and protein content decreased. However, there were no differences between fish fed 15% SWM and the control group. Thrombocytes and neutrophils showed increasing levels (p < .05) in those fed SWM diets mainly 6 hr after challenge. Increased lysozyme activity in serum and liver was registered in both groups fed SWM (p < .05). Fish fed SWM diets showed an increase in HACS in which higher haemolysis was registered at 0 hr and 3 hr (p < .05). The current study indicates that dietary inclusion of at least 15% SWM could influence selected innate immunity parameters of tilapia while maintaining growth performance and feed utilization. However, further investigations are needed to evaluate the effect of SWM on other immune parameters to better understand how this ingredient can improve the health of Nile tilapia.