Comparative evaluation of raw and fermented Eichhornia crassipes leaf meal in the diet of Cyprinus carpio fingerlings: Effects on growth performance, body composition and haemato-biochemical responses

Abstract

Eichhornia crassipes leaf meal (ELM) was fermented by solid-state fermentation using Chaetomium globosum MTCC 4179 that resulted in considerable changes in its nutrients and anti-nutrient profile. Both fermented ELM (FELM) and raw ELM were evaluated in the feed of Cyprinus carpio fingerlings through a feeding trial of 56 days. Five iso-nitrogenous and iso-caloric diets viz. C, Control (30% DORB and 0% ELM or FELM), ELM15 (15% ELM with replacement of 50% DORB), ELM30 (30% ELM with replacement of 100% DORB), FELM15 (15% FELM with replacement of 50% DORB), and FELM30 (30% FELM with replacement of 100% DORB) were prepared and fed on satiation basis to 180 acclimated fish (body weight 8.38–8.48 g) of five respective groups in triplicate with the stocking density of 12 fish /tank. Significantly (P<0.05) higher weight gain (%), specific growth rate, and protein efficiency ratio and lower feed conversion ratio (FCR) were observed in ELM15 and FELM15 groups compared to the control. However, the growth performance of ELM30 and FELM30 groups showed no significant (P>0.05) difference with control group. Furthermore, fermented diets (FELM15 and FELM30) could not improve the growth performance of fish as compared to their non-fermented counterparts (ELM15 and ELM30). Total red blood cell count, packed cell volume (%), and total serum protein (g/dl) were significantly (P<0.05) higher in ELM15 compared to other ELM and FELM-based groups. Better body composition was observed in fish of ELM15 group, however, fish of control, and ELM30 showed similar body protein, lipid, ash and total carbohydrate. Thus, it is concluded that raw ELM can be incorporated in the diet of common carp up to the level of 30% with complete replacement of DORB without compromising the growth performance of fish. However, the fermentation of ELM with Chaetomium could not impart any additional benefits in terms of growth performance of fish. In addition, dietary inclusion of 15% raw or fermented ELM, in replacement of 50% DORB, can result in higher growth performance with better health condition of common carp fingerlings.