Duckweed (Lemna minor) as a plant protein source in the diet of common carp (Cyprinus carpio) fingerlings

The present study was carried out to use dried duckweed, Lemna minor, as a dietary protein source for (Cyprinus carpio) common carp fingerlings. Four experimental diets were prepared with similar E:P ratios were fed to common carp fingerlings with an average initial weight of 16.0 g for 60 days. A diet containing 15%, 30% and 45% duckweed respectively was substituted for the commercial 32% protein control-group diet, fed in normal rations to common carp. The results revealed that there was no significant difference between the growth performance of fish that were fed diets containing up to 45% duckweed and fish that were fed the control diet (P>0.05), except for the group of fish on the 15% duckweed diet. Also, no significant difference was observed among treatments with respect to feed utilization (P>0.05). While carcass lipid content increased, protein content of the fish fed a diet of 15% duckweed increased compared to other groups (P<0.05). The results showed that a diet consisting of up to 15% content could be used as a partitial replacement for fish meal in the diet of common carp fingerlings.