Author
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Torrans, Eugene |
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Submitted to: The Catfish Journal
Publication Type: Trade Journal Publication Acceptance Date: 9/3/2009 Publication Date: 5/12/2010 Citation: Torrans, E.L. 2010. Can We Improve Catfish Growth and FCR Through Oxygen Management? The Catfish Journal. 24(9):10-11, 14 Interpretive Summary: Technical Abstract: Studies were conducted in 15 1-acre and six ¼-acre ponds over several years to determine the effect of low dissolved oxygen (DO) concentration on food conversion ratio (FCR), food consumption, growth, and net production of channel catfish. Control ponds in each study were maintained with a minimum DO concentration above 4.3 mg/L during the peak feeding months of the growing season (June-September); test ponds were maintained at 1.7 – 3.0 mg/L in different studies. The fish were stocked as fingerlings and fed once daily to apparent satiation and clean harvested at the end of the growing season in all studies. Results demonstrate that food intake is reduced when DO drops below 3.0 mg/L. At a mean minimum DO concentration of 1.7 mg/L, food consumption was reduced by 45%. FCR was poorer in larger ponds, but was not affected by DO within the range of concentrations examined. We would expect a poorer FCR at lower DO concentrations (below 1.5 mg/L) as a greater proportion of the increasingly restricted feed goes toward maintenance. Catfish can be grown from egg to food fish in two seasons, but reduced growth resulting from restricted feeding may extend the production cycle by several years. Increased mortality during an extended production cycle may cause the poor FCR’s currently reported from the industry. Management should focus on reducing the length of the production cycle to improve FCR’s. |
