U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
2009
Citation
Green, B., Perschbacher, P., Ludwig, G., 2009. Effect of using threadfin shad as forage for channel catfish fed daily or every third day. North American Journal of Aquaculture 71, 46-51.
Abstract
We evaluated whether stocking threadfin shad Dorosoma petenense as a forage fish in multiple-batch production ponds for channel catfish Ictalurus punctatus could substitute for formulated feed when channel catfish were fed daily or every 3 d. A completely randomized design in a 232 factorial arrangement was used for the experiment, which was conducted in twelve 0.1-ha earthen ponds. Prespawn adult threadfin shad were stocked at 404 kg/ha in six of the ponds, whereas the remaining ponds received no threadfin shad. Channel catfish stockers (0.35 kg/fish) were stocked at 5,040 kg/ha, and fingerlings (28.2 g/fish) were stocked at 14,820 fish/ha. Channel catfish were fed a floating feed (32% protein) to apparent satiation daily (D; 6 ponds) or every 3 d (3D; 6 ponds). After 144 d, mean channel catfish total net yield was unaffected by the presence of threadfin shad but was significantly greater for fish in the D treatment (7,256 kg/ha) than for fish in the 3D treatment (2,431 kg/ha). Mean fish weight at harvest also was greater in the D treatment than in the 3D treatment. The amount of feed administered in the 3D treatment was 62% of that used in the D treatment, thus reducing net total yield by 66% and slowing growth in fish from the 3D treatment. Nearly 90% of stockers in the 3D treatment failed to reach market size (0.68 kg/fish) and would have required a third season to reach harvest weight. At the rate used in this experiment, stocking of threadfin shad as forage fish into channel catfish production ponds did not appear to be a viable method of substituting for formulated feed during the growing season.
Comments
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