The Costs and Effects of Alternative Winter Feeding Strategies for Channel Catfish Ictalurus punctatus in Multiple-Batch Production

Abstract

Previous work suggested that feeding catfish, Ictalurus punctatus, more frequently over the winter might reduce weight loss. Twelve 0.10-ha ponds were stocked with 987 kg/ha market-sized fish and 2,960 kg/ha sub-marketable fish in November 2008 with treatments of: (1) unfed, (2) fed daily (fed 90 d), and (3) temperature-threshold feeding (fed 62 d). Total gross yield was significantly greater for the temperature-threshold feeding treatment than the unfed control, but survival and mean weight of fish at harvest were not. Net yield was negative for all treatments, due primarily to mortality of market-sized fish. Plasma glucose and insulin-like growth factor-1 did not differ significantly, but plasma osmolality was significantly lower in fasted than in fed fish. Mean feed consumption rates in vats provided evidence to support more frequent feeding over the winter. Overwintering costs were $0.11/kg with temperature-threshold feeding. Research on strategies to reduce winter mortality has potential to reduce overwintering costs.

Keywords:

• Catfish
• economics
• winter feeding
• catfish physiology

Acknowledgments

The authors thank Todd Sink, Peter Perschbacher, and Yushun Chen for helpful comments and suggestions on an earlier version of this manuscript. The assistance of the Aquaculture Research Station manager, Bauer Duke, crew, and faculty, staff, and students of the UAPB Aquaculture/Fisheries Center during stocking, sampling, and harvesting is appreciated. We would also like to acknowledge Dr. Brian Peterson (USDA-ARS, Thad Cochran National Warmwater Aquaculture Center, Stoneville, MS, USA) for his help in performing the IGF-1 assay. This study was partially funded by the USDA-Agricultural Research Service through Specific Cooperative Agreement No. 58-6225-80-26, “Economics and Improved Production Practices for Hybrid Striped Bass and Catfish and Viral Relationships to Aquaculture Biosecurity.”

Notes

1. Survival data were not arc sine transformed because the range of percentages was less than 40 (Little & Hills 1978).