Delayed Feeding of Channel Catfish Fry Stocked in Ponds

Abstract

We compared production variables between channel catfish, Ictalurus punctatus, nursery ponds fed according to industry standards, that is feeding immediately at stocking, to an alternative practice of delaying feeding for 6 wk after stocking in an effort to utilize natural pond productivity and reduce feed use. Twelve 0.04 ha ponds were fertilized and stocked with swim-up fry (4-5 d posthatch) at a rate of 10,000/pond (250,000/ha). Ponds were then randomly assigned to either the standard feeding protocol (feeding daily starting immediately at stocking) or an alternative feeding protocol (no feeding until 6 wk post-stocking). After 18 wk of production, there were no differences in water quality or zooplankton abundance between the two treatments. Fish length was not affected by treatment throughout the study, and survival and total weight harvested were similar. Total kg of feed fed was significantly reduced in the delayed feed treatment, averaging 26 kg/pond less feed fed. If proper fertilization practices are implemented, large numbers of desirable zooplankton for catfish fry culture are attained, and these zooplankton are able to sustain catfish fry stocked up to 250,000/ha. Therefore, no commercial diets are required during the first 6 wk of culture, saving over $95.55/ha in initial feed costs.

Rotenone Has Little Effect on Water Quality, Phytoplankton, Zooplankton, or Macroinvertebrates in Aquaculture Nursery Ponds

“…Furthermore, fry of both Channel Catfish and hybrid catfish (female Channel Catfish × male Blue Catfish I. furcatus ) can rely on natural food sources until reaching a development stage allowing for acceptance of a floating commercial diet without reducing growth or survival (Mischke et al. 2013, 2017). Verifying the importance of zooplankton to catfish fry culture, Mischke et al.…”

“…Mischke et al (2009) showed that when fry diets in the laboratory were supplemented with zooplankton, weight increased 40-50% over commercial diets alone. Furthermore, fry of both Channel Catfish and hybrid catfish (female Channel Catfish × male Blue Catfish I. furcatus) can rely on natural food sources until reaching a development stage allowing for acceptance of a floating commercial diet without reducing growth or survival (Mischke et al 2013(Mischke et al , 2017. Verifying the importance of zooplankton to catfish fry culture, Mischke et al (2019) used stable isotope ratios to show both Channel Catfish and hybrid catfish used zooplankton and feed equally (~50% from each source) to support growth throughout initial fry development.…”