Location: Warmwater Aquaculture Research Unit
Title: Improved Survival in Channel Catfish Fed Mannanoligosaccharides in an Extruded Diet Authors
Submitted to: Journal of the World Aquaculture Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 20, 2009
Publication Date: N/A
Interpretive Summary: Research examined the effects of extrusion temperature on the efficacy of prebiotics in channel catfish grown for 9 wks and then challenged with virulent bacteria. Weight gain and feed efficiency were similar in all treatments. Survival was higher only in diets that had been extruded at a lower temperature (225 degrees Fahrenheit). The results show that supplementing prebiotics into diets extruded at lower temperatures may provide another strategy to control enteric septicemia of catfish (ESC) in channel catfish.
Technical Abstract: Research examined the effects of extrusion temperature on the efficacy of mannanoligosaccharide (Bio-Mos) in channel catfish grown for 9 wks and then challenged with virulent Edwardsiella ictaluri. Seven hundred and fifty catfish (10.3 ± 0.3 g) were randomly assigned to six treatments with five replicates each: Con-Sink (36% crude protein (CP) catfish sinking diet, control); Bio-Mos®-Sink (36% CP catfish sinking diet with Bio-Mos® supplemented at 4 g/kg); Control-255 (36% CP catfish diet extruded at 255 degrees Fahrenheit); Bio-Mos®-255 (36% CP catfish diet extruded at 255 degrees Fahrenheit with Bio-Mos® supplemented at 4 g/kg); Control-225 (36% CP catfish diet extruded at 225 degrees Fahrenheit); and Bio-Mos®-225 (36% CP catfish diet extruded at 225 degrees Fahrenheit with Bio-Mos® supplemented at 4 g/kg). SGR was higher and FCR was lower for the fish fed floating diets compared to sinking diets (P < 0.01). Survival after E. ictaluri challenge was higher (P < 0.01) in the Bio-Mos-sink compared to Control-sink (60.0 +/- 5.3% vs 40.0 +/- 6.4%) and Bio-Mos®-225 compared to Control-225 (70.0 +/- 4.2% vs 45.0 +/- 5.4%). Survival after E. ictaluri challenge was similar between the Bio-Mos®-255 compared to Control-255 (50.0 +/- 5.2% vs 55.0 +/- 7.4%). Extrusion temperature appears to affect the efficacy of Bio-Mos added to catfish diets. Extruding catfish diets supplemented with Bio-Mos at a lower temperature may provide another strategy to control ESC in catfish.