Effects of different European catfish feeds on production parameters and water quality in limnocorrals

Absztrakt

Fishmeal replacement in diets for intensive aquaculture has become a high priority area for the global aquaculture industry. In this study, a 95 day long experiment was carried out between June and September with one-year-old European catfish (Silurus glanis) (72.7 ± 1.3 g initial weight). The fish were fed with 6 isocaloric and isoproteic (35% CP) feeds in three replications. Feeds differed according to the main protein source as follows: fish meal (FM), meat meal (AP), corn (SC), wheat (SW), wheat treated with Axtra XB xilanase (SW-A), wheat treated with Belfeed B 1100 MP xilanase (SW-B). FM diet was regarded as the control. The mean body weight rose from 72.7 ± 1.3 g to 325.9 ± 14.2 g. The mean body weights of AP and FM groups differed significantly from the SW, SW-A and SW-B groups. The SGR range was significantly higher in the AP and FM diets. The feed conversion ratio of AP group did not differ from the FM group significantly. Significant differences were found among the water quality parameters in case of total suspended solids (TSS). Significant differences were also found among FM, AP and SW-A treatments in the Kjeldahl-N content of the sediment at the end of the experiment. According to the results processed animal protein is a suitable alternative instead of fish meal. Enzymatic supplementations have not been as useful as expected. Its reason needs further investigation.