Influence of replacement of fish meal with the earthworm Eisenia fetida on growth performance, feed utilization and blood parameters of Nile tilapia (Oreochromis niloticus)

Abstract

A total of 450 of Oreochromis niloticus fingerlings with initial average weight of 4.10±0.02g were obtained by the Fish Hatchery of the General Authority for Fisheries Development, Aswan governorate, to evaluate the effect of replacement of fish meal with earthworm meal (EWM), on growth performance, survival and blood parameters of Nile tilapia. The stocking density was 30 fingerlings per tank and each diet was tested in triplicate. Fish were manually fed with experimental diets at the rate of 5%, twice/day for 60 days. Once every ten days, the total number of survivors in each tank was counted and fish biomass determined. Crude protein content of Nile tilapia juveniles increased significantly (P<0.01) for juveniles maintained at the control, 75, 100% EWM. While average lipid content less for Juveniles fed at 0% EWM. The Juveniles maintained at 75, 50, and 100% EWM were have significantly (P<0.01) higher SGR, PPV, PER, ER and the best food conversion ratio FCR (wait/gain) than the other Juveniles. There were no significant differences (P<0.01) in mean values of creatinine, triglyceride, lipase, glucose, albumin and globulin among all the diets, while cholesterol and amylase varied significantly.