Effect of carryover biomass of channel catfish on production and profitability in intensively aerated multiple-batch system

Abstract

Multiple-batch production is the most common farming strategy for raising channel catfish. Increased adoption of intensified alternative production practices has changed the cost structure of many catfish production practices including multiple-batch systems. Production efficiency in multiple-batch production can be enhanced by providing optimal stocking recommendations for fingerlings and carryover fish. Twelve 0.4-ha ponds were understocked with 20,782 channel catfish fingerlings (mean weight = 30 g/fish) at three different carryover biomass rates (3440; 4580; and 5702 kg/ha). Fish were fed once daily to apparent satiation with a 28% protein floating feed, and ponds were aerated with a 7.4-kW electric paddlewheel aerator. Gross, net, daily net yields, sub-marketable yields (<0.54 kg), growth (g/day), and survival were statistically similar among the three treatments, but yield of marketable fish yield (fish ≥0.54 kg) increased significantly with increased carryover biomass. The cost of production was reduced while net returns increased with increased carryover biomass. The lowest carryover biomass treatment (3440 kg/ha) had negative cash flow and net returns when sub-marketable fish were not assigned value. However, all three carryover biomass treatments attained positive annual net cash flows and net returns when sub-marketable fish were valued as revenue, the two higher carryover biomass treatments (4580 and 5702 kg/ha) outperformed the low carryover biomass treatment (3440 kg/ha). This study indicates channel catfish carryover biomass rates should be between 4580 and 5702 kg/ha to improve cost efficiency in intensively aerated, multiple-batch production systems.