Submitted to: Aquaculture
Publication Type: Abstract Only
Publication Acceptance Date: 7/22/2003
Publication Date: 3/1/2004
Citation: Torrans, E.L. 2004.Effect of D.O. on Food Consumption, Growth, Production, and Food Conversion in Channel Catfish, Ictalurus punctatus, Grown in Earthen Ponds. [Abstract]. In: Abstract Book. Aquaculture America, March 1-5, 2004, Honolulu, Hawaii. p. 597. Interpretive Summary:
Technical Abstract: Farmers have long known that increased aeration allows them to feed more and grow more fish. However, since we still do not know how specific dissolved oxygen (D.O.) concentrations affect various production parameters, every farm has its own oxygen/aeration management plan. The purpose of this study was to determine the effect of daily minimum D.O. concentration on food consumption, growth, production, and food conversion of channel catfish grown in ponds. Six quarter-acre ponds were each equipped with three ½-hp aerators and one ½-hp circulator. D.O. and temperature were continuously monitored with a commercial oxygen monitor, which also controlled aeration. Aeration was initiated in the control treatment both years when the D.O. dropped below 5.0 mg/L; aeration was initiated in the low oxygen treatment when the D.O. dropped below 2.5 mg/L (2001 study) or 1.5 mg/L (2002 study). Fish were fed daily to apparent satiation with floating feed. Delaying aeration until the D.O. dropped to 2.5 mg/L (in 2001) reduced feed consumption by 6.3% (Figure 1). Other parameters were similar. Delaying aeration until the D.O. dropped to 1.5 mg/L (in 2002) had major impacts: average fish weight was 30.5% less; net production was 54.0% less, and food consumption was 45.1% less (Figure 1) than the control treatment. Food conversion was not significantly affected by reduced oxygen. Even at the high feeding rates of 2002 (up to 680 kg/ha/day; 44,066 total kg/ha in one pond), other water quality parameters were acceptable. Channel catfish swim-up fry were stocked at 400,000/ha in 2003 and managed under two different oxygen management regimes. Data will be presented on that study as well.