Submitted to: Aquaculture America Conference
Publication Type: Abstract only
Publication Acceptance Date: 8/26/2003
Publication Date: 3/1/2004
Citation: Trimpey, J., Engle, C., Heikes, D., Davis Jr, K.B. 2004. A comparison of new in-pond grading technology to live car grading for food-sized channel catfish, ictalurus punctatus [abstract]. In: Aquaculture America Conference. p. 600. Interpretive Summary:
Technical Abstract: Grading trials were performed at the University of Arkansas at Pine Bluff and on commercial catfish ponds to determine if a new in-pond horizontal floating bar grader outperforms current live car grading techniques. Trials were conducted at UAPB with three fish size distributions: (75:25, 50:50, 25:75) % sub-harvestable:harvestable fish at three different temperature ranges. Commercial trials were replicated three times during each temperature range. Stress was measured by plasma glucose and cortisol levels. Grading speed was significantly greater with the UAPB/Heikes grader than the traditional live car. Chi-square tests show that the UAPB/Heikes grader significantly decreased the proportion of sub-harvestable fish during all trials. The traditional live car did not significantly grade fish in the 25:75 distributions during hot and cold trials or during commercial trials. The UAPB/Heikes grader returned from 2-52 times more kilograms of sub-harvestable fish to the pond than the traditional live car grader. Repeated measures tests indicate that grading performance of the traditional live car was significantly influenced by size distribution and temperature. The traditional live car graded best during the 50:50 size distribution during all three temperature ranges. The UAPB/Heikes grader was only significantly affected by size distribution with best performance at the 25:75 size distribution. Temperature had no effect on grading efficiency with the UAPB/Heikes grader. Glucose and cortisol levels in fish graded with the two graders were not significantly different. The UAPB/Heikes grader can reliably grade fish more accurately and consistently over a broader range of temperatures and size distributions than the traditional live car.