Comparative Production of Channel Catfish and Channel x Blue Hybrid Catfish Subjected to Two Minimum Dissolved Oxygen Concentrations

The effect of daily minimum dissolved oxygen (DO) concentration on the growth and yield of channel catfish Ictalurus punctatus and channel catfish hybrids (female channel catfish x male blue catfish I. furcatus) sharing the Jubilee strain of channel catfish as the maternal parent was evaluated in a 234-d study in sixteen 0.1-ha earthen ponds (15,113 fish/ha). Ponds were managed to maintain a minimum DO concentration of 25% or 50% of saturation. The total consumption of 32%-protein feed at the high and low DO concentrations was 12,973 and 10,262 kg/ha, respectively, for channel catfish and 12,805 and 11,592 kg/ha, respectively, for hybrid catfish. The net yield of hybrid catfish (8,069 kg/ha) did not differ from that of channel catfish (8,037 kg/ha), but the mean individual weight of hybrid catfish was significantly greater. Net yield (8,740 kg/ha), individual weight (0.75 kg/fish), and feed consumption (12,889 kg/ha) were higher for fish in the high DO than in the low DO concentration treatment (7,366 kg/ha, 0.65 kg/fish, and 10,927 kg/ha, respectively). Net yield, individual weight, and feed consumption for channel catfish were 22, 23, and 21% lower, respectively, for the low-DO treatment than for the high-DO treatment, whereas the respective differences for the hybrid catfish were 10, 4, and 10%. Growth did not differ between fish genetic groups but was faster in the high-DO treatment. Channel catfish grew faster in the high-DO treatment, whereas the growth of hybrid catfish did not differ with respect to DO concentration.