In conclusion, we support Mischke et al.'s (2013) management recommendation that manufactured feeds be withheld from nursery ponds during the early weeks after stocking fish. We add, however, that live zooplankton and insects continue to support growth long after feed is first used by the fish. Thus, zooplankton and insect densities in ponds must be adequate to support the consumptive demands of the fish crop throughout the growing season to achieve the fastest fish growth rates. Because zooplankton densities during summer months in eutrophic nursery ponds tend to be extremely high, as in the current study (Filbrun et al., 2013), it is unlikely that most ponds require fertilization to enhance live prey densities to meet fish foraging demands. Should fertilization be required to increase zooplankton densities, we recommend careful additions of inorganic nitrogen and phosphorus at rates such as those recommended by Culver et al. (1993). Although we applied the use of stable isotopes to quantify live prey and feed contributions to channel catfish growth in nursery ponds, this research approach can be applied to any species and culture system to improve production efficiency and sustainability by refining feed use.