Inclusion of cricket (Gryllus bimaculatus) meal in African catfish (Clarias gariepinus) feed influences disease resistance

Abstract

In our present study, we observed the effect of cricket meal (CM) on disease resistance of African catfish. Fish were fed diets containing 350 g kg–1 and 400 g kg–1 of CM and 350 g kg–1 of fishmeal as control. The fish were divided into triplicates treatments of ten fish per replicate, weighed 22.5±0.6 g and fed with experimental diets for 40 days before being challenged against Aeromonas hydrophila. Relative percentage of survival (RPS) was recorded over 12 days post-challenge. White blood cell count, total protein, globulin and lysozyme showed significantly increasing levels in those fed with cricket meal diet compared to the control group. Mortalities at 12-day post-challenge significantly decreased to 30% (RPS: 66.7%) and 27% (RPS: 70%) for 35% and 40% CM respectively compared to 90% mortality in control group. Intestines and liver tissues of infected fish were dissected for pathogenic confirmation. The intestines of control diet showed the highest bacterial load (58.2×107 cfu g–1) compared to CM diets. The current study indicates that dietary CM could enhance the innate immune system and disease resistance of African catfish.

Keywords

• Immunostimulant
• bacteria challenge
• fishmeal
• fish feed
• cricket meal
• Aeromonas hydrophilla