The Effect of Probiotic-Induced Fermentation of Restaurant Waste on the Growth of Common Carp (Cyprinus carpio) Fry

Abstract

The study explores using the fermentation process to convert organic restaurant waste into fish feed, a promising solution for aquaculture. The aim is to determine the best type and dosage of probiotics for fermenting restaurant waste (FRWM) and evaluate their impact on common carp (Cyprinus carpio) fry growth. Three commercial probiotics (P1, P2, and P3) were used at an 8% concentration for fermenting the waste. The best result from the fermentation trial was tested as feed containing different FRWM proportions: 0% (TA), 10% (TB), 20% (TC), 30% (TD), and 40% (TE) with 30% protein content. The trial lasted 42 days, assessing waste chemical composition before and after fermentation, growth rate, amylase and protease activity, feed conversion, survival rate, and water quality. Results showed P1 was most effective, increasing FRWM protein content by 84.25% and reducing crude fiber and fat by 15.17% and 3.94%, respectively. TE (40% FRWM) yielded the best outcomes, with fry common carp achieving a 1.05% daily growth rate and a feed conversion ratio of 0.80, indicating efficient feed utilization. TC (20% FRWM) exhibited the highest survival rate at 88.33%. The inclusion of FRWM influenced amylase activity, increasing enzyme levels and improving feed efficiency and growth rate. In conclusion, using FRWM, fermented with P1 probiotics, showed significant improvements in its composition, leading to enhanced fish growth and feed utilization. The 40% FRWM diet demonstrated the best fish growth rate and feed conversion performance. These findings support using fermented restaurant waste as sustainable and nutritious fish feed in aquaculture.