Effect of partially replacing fish meal with honey locust seed (Gleditsia triacanthos) on growth, feed utilisation and body composition of mirror carp, Cyprinus carpio, fingerlings

Abstract

Honey locust seed (HLS) (Gleditsia triacanthos) was evaluated as a partial replacement for fish meal (FM) in Cyprinus carpio fingerlings diets formulated to contain 38% crude protein, 13% lipid and 19.9 MJ/kg gross energy. An 60-day feeding trial was conducted in a recirculation system aquarium. HLS was included in the diets at different levels (0, 100, 200, 300 and 400 g raw and 100, 200, 300 and 400 g heat-treated for diets Control, Rw1, Rw2, Rw3, Rw4 Ht1, Ht2, Ht3 and Ht4, respectively) and FM was replaced by 0%, 5%, 10%, 15% and 20% of HLS (raw and heat-treated). The fish were handfed daily at of 3% of their body weight during the experiment. Diet had a significant effect on the growth performance. Heat treatment increased the inclusion level of HLS. There were no significant differences (P>0.05) among fish fed diets Control, Rw1, Rw2, HT1, HT2 and HT3 in terms of growth performance. Fish fed diets containing higher levels (>30%) of raw HLS seed had significantly lower whole body fat content. Raw and heat-treated HLS has potential as an alternative feed ingredient. These results show that up to 20% Raw HLS can be used to replace 10% of FM in diets for mirror carp. However, HLS should be heat-treated if inclusion rates are to exceed 20% of the diet.