An economic analysis of the performance of three sizes of catfish Ictalurus punctatus fingerlings understocked in multiple-batch production

摘要

Different sizes of catfish fingerlings understocked in multiple-batch production stay result in different survival, yield, cost, and economic risk. A pond production study was conducted to compare net yield, growth, survival, costs, and economic risk of understocking 7.6-cm, 12.7-em, or 17.8-cm channel catfish letalurus punctatus fingerlings in growout ponds. Fingerlings were understocked at 15,000/ha with 1,369 kg/ha carryover fish averaging 0.58 kg. Mean growth rate increased significantly with size of fingerling understocked (1.4 +/- 0.2 g/d, 1.8 +/- 0.07 g/ d, and 2.2 +/- 0.06 g/d for 7.6-cm, 12.7-cm, and 17.8cm understocked fingerlings, respectively). Mean individual weights at harvest also increased significantly with size at stocking but none of the understocked fingerlings reached minimum market size (0.57 kg) over the 201-d study period. Survival of the smallest (7.6-cm) understocked fingerlings was significantly lower, but there was no difference in survival between the two other treatments. Net yields were highest fur the two treatments understocked with 12.7- and 17.8-cm catfish and significantly lower fur the treatment understocked with 7.6-cm fish. Growth of huge carryover fish was significantly less in the treatment understocked with 17.8-cm fingerlings. Breakeven production costs were highest for the treatment understocked with 7.6-cm fish and lower for the other two treatments. Tile risk analysis showed that it was very likely that the 12.7- and 17.8-cm understocked fish could be grown profitably (very little risk of costs exceeding