Location: Warmwater Aquaculture Research UnitTitle: Effect of grading fingerling hybrid catfish on food fish size distribution Author
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/5/2015
Publication Date: 2/3/2015
Citation: Torrans, E.L., Ott, B.D. 2015. Effect of grading fingerling hybrid catfish on food fish size distribution. Meeting Abstract. P. 15.
Technical Abstract: In spite of record high feed prices (averaging over $400/ton during the past five years) and a flood of cheap imports being dumped on the country, the U.S. farm-raised catfish industry has remained viable by increasing production intensity while decreasing FCRs (food conversion ratios). Two technical advances led to this – an understanding of the impact of DO (dissolved oxygen) management on the feed intake and growth of catfish, and the commercialization of hybrid catfish fingerling production. By maintaining the minimum DO concentration at or above 2.5-3.0 ppm, feed intake and growth is more than doubled over traditional oxygen management regimes. Hybrid catfish, with their greater disease resistance, allow farmers to utilize this increased feed consumption and grow out food fish in a single season from fingerling, compared to 2-4 years typically required of channel catfish a decade ago. Farmers now can truly capitalize on intensive production systems, greatly increasing yields while achieving FCRs better than 2.0:1. Two systems, “split-ponds” and “intensively aerated traditional ponds” are the production systems now used by most farmers producing yields in excess of 12,000 lbs/acre. In this study we attempted to push the limits of catfish production in traditional earthen ponds using high stocking rates of hybrid catfish (20,000/acre) and intensive aeration (10 hp/acre) capable of maintaining a minimum DO over 3.0 ppm while feeding the fish to satiation. This was compared to a more traditional stocking rate of 5,000/acre and similar DO management. At the higher stocking rate we achieved an average (N=3) yield of 27,704 lbs/acre, compared to 10,176 lbs/acre at the lower stocking rate. Although the harvest size was smaller at the higher density (1.6 lbs vs. 2.2 lbs, resulting in a slightly greater fingerling cost per lb produced), the FCR was identical (1.8) and the aeration cost similar. Commercial farmers in Arkansas, Mississippi and Alabama, while not achieving these yields yet, have produced up to 15,000-20,000 lbs/acre using similar techniques in 3-6 acre commercial ponds. Farmers not ready to construct split ponds but willing to divide larger ponds can greatly increase their on-farm production using intensive aeration.