Location: Warmwater Aquaculture Research Unit
2015 Annual Report
Objectives
1) Evaluate alternative feedstuffs and optimize feed formulations using traditional and alternative feedstuffs for cost-effective production of catfish, and determine if nutrient requirements differ for hybrid and channel catfish.
Sub-objective 1.1 Evaluate diets using alternative feedstuffs in low-protein diets for pond-raised hybrid catfish.
Sub-objective 1.2 Evaluate fortification of alternative diets with lysine and methionine to improve processing yield of channel catfish.
Sub-objective 1.3 Complete replacement of soybean meal using a combination of lower-cost protein sources for pond-raised hybrid catfish.
Sub-objective 1.4 Evaluate 32% or 36% protein, traditional or alternative feeds for fingerling hybrid catfish.
Sub-objective 1.5 Evaluation of growth and disease resistance of fish fed diets supplemented with taurine.
2) Develop more cost effective feeding and production strategies for hybrid and catfish production.
Sub-objective 2.1 Evaluate effects of maintenance feeding on growth and processing yield of market-size hybrid catfish.
Sub-objective 2.2 Compare hybrid fry production when feeding immediately at stocking with fry fed under an alternative feeding strategy of waiting six weeks before offering commercial diets.
3) Evaluate co-culture of alternative species for effects on water quality, biological control of disease vectors, and supplemental income for catfish producers.
Sub-objective 3.1 Co-culturing redear sunfish with channel catfish under commercial conditions.
Sub-objective 3.2 Extensive production of prawn Macrobrachium rosenbergii in fallow catfish production ponds for crop diversification.
Approach
Three 24% protein diets containing 30, 20, and 15% soybean meal will be compared with a 28% protein control diet. Hybrid catfish fingerlings will be stocked in ponds at 6,000 fish/acre. Each diet will be fed to five replicate ponds. All ponds will be harvested in October/November. A partial budget analysis based on feed and fish prices will be conducted to determine the economic benefit (if any) of using low-protein alternative diets versus the traditional control diet.
This study will evaluate five 28% protein diets fortified with varoious supplements. Experimental design, diet analyses, procedures for stocking, feeding, pond management, data collection and statistical and economic analysis will be the same as described for Sub-objective 1.A.
All soybean meal in hybrid catfish feeds will be replaced with various combinations of cottonseed meal, distiller’s grains with solubles, peanut meal, and porcine meat and bone meal. Pond will be stocked with hybrid catfish fingerlings, and diet analyses, experimental design, procedures for stocking, feeding, pond management, data collection and statistical analysis, and economic analysis will be the same as described for Sub-objective 1.A.
Four thousand small hybrid catfish fingerlings will be stocked into 20 tanks with 200 fish each. Four diets of 32% or 36% protein using either soybean meal or soybean substitutes will be evaluated. Diet, statistical, and economic analysis will be the same as described for Sub-objective 1A.
Growth and disease resistance of juvenile channel catfish will be evaluated in fish fed diets with varying levels of taurine in replicated aquaria.
The proposed study will evaluate effects of no feeding, maintenance feeding, and re-feeding on growth, feed conversion ratio, and processing yield of hybrid catfish. Market-size hybrid catfish (1.5 lb) will be stocked into ponds at the end of May or early June. The experimental design, procedures for stocking, feeding, pond management, data collection and statistical analysis will be the same as described for Sub-objective 1.A.
This study will compare production of hybrid fry fed immediately at stocking in 0.4 ha ponds with that of fry not fed until 6 weeks after stocking.
Four ponds will be stocked with channel catfish (600 fish/pond) and redear sunfish (10 fish/pond); four ponds will be stocked with redear sunfish only (10 fish/pond); four ponds will be stocked with catfish only (600 fish/pond). The study will be repeated yearly with the same stocking rates but with varying fish size. Catfish will be fed and managed according to standard industry practices and cultured through one production season.
Each treatment will consist of 4 replicate ponds to evaluate using hay, planted wheat, or rice as substrates to increase freshwater prawn production. Ponds with no substrate addition will served as controls. Ponds will be stocked with 10,000 prawn/ac. All ponds will be fed range cubes. Prawns will be harvested in the fall. All prawns will be counted and collectively weighed, and production will be compared among the treatments.
Progress Report
Studies were conducted evaluating feeds and feeding practices for hybrid catfish production. Low-protein and alternative diets were evaluated for pond raised hybrid catfish. Three 24% protein diets containing decreasing levels of soybean meal (30, 20, and 15%) and increasing levels of cottonseed meal and corn germ meal were compared with a 28% protein control diet. Hybrid catfish fingerlings (mean initial weight = 71 gram (g)/fish) were stocked into 20 earthen ponds at a density of 14,826 fish/hectare (ha). Fish were fed once daily for 191 days to an approximate weight of 2 pounds. There were no significant differences in total diet fed, net yield, weight gain, feed conversion ratio (FCR), survival, or fillet proximate nutrient composition among dietary treatments (Probability = 0.10). However, regression analysis showed for fish fed 24% protein diets there was a linear increase in FCR as soybean meal levels decreased (Probability = 0.06). Compared with fish fed the 28% protein control diet, fish fed 24% protein diets had lower carcass and fillet yield. Results demonstrate a 24% protein alternative diet containing 20% soybean meal may be substituted for 28% protein diets for hybrid catfish during food fish production. A pond study has been initiated to determine if market-size hybrid catfish can be maintained by feeding once a week to satiation and if losses in processing yield can be restored in feed restricted fish following a daily feeding regimen. Ponds have been stocked and feeding regimens implemented. Fish will be harvested at the end of the production season to determine treatment effects. Data will be used to make feeding recommendations in the event of harvest delays. Hybrid fry production studies have been initiated evaluating feed management practices to reduce feed costs. This study is comparing production of hybrid fry fed immediately at stocking with that of fry not fed until 6 weeks after stocking. Fry ponds at the Thad Cochran National Warmwater Aquaculture Center in Stoneville, MS, have been prepared and fertilized with the recommended fertilization strategies. Hybrid fry were stocked into the nursery ponds at 200,000/ha. Fry are currently being fed commercial feeds according to their treatment assignment (fed commercial diets immediately or not fed for 6 weeks) and cultured using common practices. In the fall, all fingerlings will be harvested and total weight and final survival rates will be compared between treatments. Zooplankton, phytoplankton, and water quality (pH, ammonia, nitrite, and dissolved oxygen) are being sampled and will be compared between treatments using a Mixed Model procedure for repeated measures throughout the study.
Accomplishments
1. Use of alternative feed ingredients to reduce production costs of catfish. Previous research has shown no significant differences in weight gain and feed efficiency among hybrid catfish fed diets with protein levels ranging from 28 to 36%. Since the price of catfish food fish diets has reached nearly U.S. $600/ton, there is interest in evaluating low-protein diets for pond-raised hybrid catfish. In efforts to reduce feed costs, scientists at Mississippi State University at Stoneville, MS, compared 24% protein, traditional and alternative diets containing various soybean meal levels with a 28% protein control diet for pond-raised hybrid catfish. Results show pond-raised hybrid catfish can be fed a 24% protein diet with 20% soybean meal from large fingerlings to market size without significantly affecting net yield, weight gain, feed conversion ratio, survival, and fillet proximate composition. However, fish fed 24% protein diets had reduced carcass and fillet yield compared with fish fed the 28% protein control diet. At moderate feed prices a 28% protein diet with ingredient composition similar to the one used in this study should be used to ensure optimum fish growth, feed efficiency, and processing characteristic of hybrid catfish. However, a 24% protein alternative diet with 20% soybean meal may be substituted for 28% protein diets for production of food-sized hybrid catfish, for example, when feed prices are high or when market-size fish must be maintained for extended periods before harvest.
Review Publications
Li, M.H., Robinson, E.H., Lucas, P.M. 2015. Apparent phosphorus availabilities of selected traditional and alternative feedstuffs for channel catfish. North American Journal of Aquaculture. 77:136-140.
Li, M.H., Robinson, E.H., Lucas, P.M., Bosworth, B.G. 2015. Evaluation of low-protein alternative diets for pond-raised hybrid catfish, Ictalurus puncatus X Ictalurus furcatus. Journal of the World Aquaculture Society. 46:228-234.
Li, M.H., Robinson, E.H., Bosworth, B.G., Torrans, E.L. 2014. Growth and feed conversion of pond-raised hybrid catfish harvested at different sizes. North American Journal of Aquaculture. 76:261-264.
Griffin, M.J., Khoo, L.H., Steadman, J.M., Ware, C., Quiniou, S., Mischke, C.C., Terrence, G.E., Wise, D.J. 2014. Chronic pathology and longevity of Drepanocephalus spathans infections in juvenile channel catfish. Journal of Aquatic Animal Health. 26(4):210-218.
Mischke, C.C., Tucker, C.S., Wise, D.J., Brown, T.W. 2015. DEET (N,N-diethyl-m-toluamide) toxicity to channel catfish Ictalurus punctatus sac fry. Journal of the World Aquaculture Society. 46:(3)344-347.
Renukdas, N., Engle, C., Lochmann, R., Li, M., Avery, J., Tucker, C.S., Bosworth, B.G. 2014. Performance of alternative diets containing solvent-extracted distillers dried grains with solubles compared to traditional diets for pond-raised channel catfish Ictalurus punctatus and hybrid catfish I. punctatus x I. furcat. Journal of the World Aquaculture Society. 45:290-300.
