Intensive production of fish in raceways are conducive to carefully controlled feeding practices and inventory management. Though feeding below satiation will not yield maximum growth, it has been shown to improve feed efficiency. A tool was developed to estimate daily ration and create a production plan based on empirical data describing potential growth across a range of water temperature. Daily ration is based on potential growth, water temperature, size of fish stocked, number stocked, date of stocking, condition factor, and estimated feed conversion. An option to input target mortality distributes loss evenly throughout the culture interval. Each day ration by both weight and volume, total fish weight, average fish weight, feeding rate as %BW/day, are determined creating a day by day production plan. It also estimates the amount and size of feed required for the culture unit during the culture period.
This tool has been in use with rainbow trout and is being developed for use in floating raceways with largemouth bass. Trout (150g/fish) in one set of raceways were fed a commercial diet (44% protein, 20% fat) to apparent satiation. Another set of raceways were fed a daily ration using the tool set at 86% of growth potential. Feeding with the tool yielded a relative harvest of 87% as compared with yield in the satiation treatment. Feed conversion for fish fed to satiation was 1.53 whereas feed conversion was 1.12 for fish fed a ration based on the tool.
As a management device, the tool can run different scenarios to determine what size fish to stock, when to stock, when fish in production can be expected to reach harvest size, or weight of fish over the market interval.