Development of Channel Catfish (Ictalurus punctatus) Farming Models for Improved Management

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
307	3710	1060	35%
307	3713	1060	20%
307	3715	1060	35%
307	3719	1060	10%

Progress 10/01/05 to 09/30/13

Outputs
Target Audience: catfish farmers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Ten graduate students and one undergraduate student were trained in the development and use of the various models developed. How have the results been disseminated to communities of interest? Results have been disseminated in extension newsletters, fact sheets, multiple presentations at industry trade association meetings, extension meetings, and professional scientific meetings. What do you plan to do during the next reporting period to accomplish the goals? This project has ended.

Impacts
What was accomplished under these goals? More than 20 different models of catfish farming practices were developed and used to evaluate the most profitable management strategies.

Publications

Type: Journal Articles Status: Published Year Published: 2011 Citation: Nanninga, A., C.R. Engle, N. Stone and A. Goodwin. 2011. Winter feeding of channel catfish Ictalurus punctatus in multiple-batch production. North American Journal of Aquaculture 73:1-8.
Type: Journal Articles Status: Published Year Published: 2008 Citation: Kumar, G., K. Quagrainie and C. Engle. 2008. Factors that influence frequency of purchase of catfish by U.S. households in selected cities. Aquaculture Economics and Management 12(4):252-267.
Type: Other Status: Published Year Published: 2012 Citation: Engle, C.R. 2012. Introduction to financial management of aquaculture business. SRAC Publication No. 4400, Southern Regional Aquaculture Center, Stoneville, Mississippi.
Type: Other Status: Published Year Published: 2012 Citation: Engle, C.R. 2012. Assessing the financial position of an aquaculture business: using balance sheets. SRAC Publication No. 4401, Southern Regional Aquaculture Center, Stoneville, Mississippi.
Type: Other Status: Published Year Published: 2012 Citation: Engle, C.R. 2012. Determining the profitability of an aquaculture business: using income statements and enterprise budgets. SRAC Publication 4402, Southern Regional Aquaculture Center, Stoneville, Mississippi.
Type: Other Status: Published Year Published: 2012 Citation: Evaluating the liquidity/cash position of an aquaculture business: using cash flow statements. SRAC Publication No. 4403, Southern Regional Aquaculture Center, Stoneville, Mississippi.
Type: Other Status: Published Year Published: 2012 Citation: Engle, C.R. 2012. Managing fish businesses in hard times workshop held in Lonoke, Arkansas. Aquafarming 29(1):2.
Type: Other Status: Published Year Published: 2011 Citation: Engle, C. 2011. Statistical analysis looking at break even costs of catfish production. The Catfish Journal 25(8):15.
Type: Other Status: Published Year Published: 2008 Citation: Engle, C.R. and N.M. Stone. 2008. The hidden costs of small-scale aquaculture. Aquaculture Magazine 33(5):24-27.
Type: Other Status: Awaiting Publication Year Published: 2014 Citation: Engle, C.R. and N. Stone. In press. SRAC 1800 costs of small-scale catfish production for direct sales. Revision. Southern Regional Aquaculture Center, Stoneville, Mississippi.
Type: Journal Articles Status: Awaiting Publication Year Published: 2014 Citation: Johnson, K., C. Engle and B. Wagner. In press. Comparative economics of U.S. catfish production strategies: evidence from a cross-sectional survey. Journal of the World Aquaculture Society.
Type: Journal Articles Status: Awaiting Publication Year Published: 2014 Citation: Renukdas, N., C.R. Engle, R. Lochmann, M.H. Li, J. Avery, C. Tucker, and B. Bosworth. In press. 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, Ictalurus punctatus x Ictalurus furcatus. Journal of the World Aquaculture Society.
Type: Journal Articles Status: Awaiting Publication Year Published: 2014 Citation: Dey, M., A. Rabbani, K. Singh, and C. Engle. In press. Determinants of retail price and sales volume of catfish products in the United States: an application of retail scanner data. Aquaculture Economics & Management.
Type: Journal Articles Status: Awaiting Publication Year Published: 2014 Citation: Kumar, G. and C.R. Engle. In press. Optimizing feeding and stocking strategies over the 24-month catfish production cycle: a mixed integer multi-year programming model. Aquaculture Economics & Management.
Type: Journal Articles Status: Published Year Published: 2013 Citation: Kumar, G. and C.R. Engle. 2013. Costs of winter feeding of channel-blue hybrid catfish. Journal of the World Aquaculture Society 44(4):511-519.
Type: Journal Articles Status: Published Year Published: 2013 Citation: Engle, C., G. Kumar, R. Lochmann, B. Bosworth, and M. Thompson. 2013. Effects of 28% protein diets differing in quality on channel catfish performance, processing traits, and production economics in a multi-batch system. Journal of Applied Aquaculture 25(2):102-112.
Type: Journal Articles Status: Published Year Published: 2012 Citation: Lochmann, R., C. Engle, G. Kumar, M.H. Li, J. Avery, B. Bosworth, and C. Tucker. 2012. Multi-batch catfish production and economic analysis using alternatives (low-cost) diets with corn gluten feed and traditional diets with meat and bone meal. Aquaculture 366-367:34-39.
Type: Journal Articles Status: Published Year Published: 2012 Citation: Pugliese, N., D. Heikes, C. Engle, B. Bosworth, and R. Lochmann. 2012. Evaluation of the economics of multi-batch channel catfish Ictalurus punctatus production fed an industry standard and three alternative diets. Journal of Applied Aquaculture 24:271-282.
Type: Journal Articles Status: Published Year Published: 2012 Citation: Bastola, U., C.R. Engle, A. Haukenes, and D. Freeman. 2012. The costs and effects of alternative winter feeding strategies for channel catfish Ictalurus punctatus in multiple-batch production. Journal of Applied Aquaculture 24(4):283-298.
Type: Journal Articles Status: Published Year Published: 2012 Citation: Bastola, U. and C.R. Engle. 2012. Economically important production relationships in channel catfish (Ictalurus punctatus) foodfish production: A review. Reviews in Aquaculture 4:1-14.
Type: Journal Articles Status: Published Year Published: 2012 Citation: Sudhakaran, P.O., C.R. Engle, and D. Heikes. 2012. Evaluation of feed response methods to estimate inventory of catfish in commercial ponds. Journal of Applied Aquaculture 24:32-41.
Type: Journal Articles Status: Published Year Published: 2011 Citation: Engle, C.R., M. Thompson, and A. Nanninga. 2011. The effect of varying biomass of carryover fish in multiple-batch catfish (Ictalurus punctatus) poond production. Journal of the World Aquaculture Society 42(6):899-905.
Type: Journal Articles Status: Published Year Published: 2011 Citation: Engle, C.R. and G. Kumar. 2011. The effect of cash flow and credit constraints on financial feasibility and stocking strategies on U.S. catfish farms: a mixed-integer multi-stage programming approach. Aquaculture Economics and Management 15(3):70-91.
Type: Journal Articles Status: Published Year Published: 2011 Citation: Engle, C.R., B. Southworth, P.O. Sudhakaran, and A. Nanninga. 2011. Production and economic effects of in-pond grading of channel catfish. Aquacultural Engineering 45(1):1-8.
Type: Journal Articles Status: Published Year Published: 2010 Citation: Engle, C., G. Kumar, and D. Bouras. 2010. The economic trade-offs between stocking fingerlings and stockers: a mixed integer multi-stage programming approach. Aquaculture Economics and Management 14(4):315-331.
Type: Journal Articles Status: Published Year Published: 2010 Citation: Nanninga, A. and C.R. Engle. 2010. Effects of feeding frequency on multiple-batch channel catfish Ictalurus punctatus production and costs when understocked with large stockers. Journal of the World Aquaculture Society 41(4):594-602.
Type: Journal Articles Status: Published Year Published: 2010 Citation: Kumar, G. and C. Engle. 2010. Production performance and cost of food fish production from fingerlings of channel-blue F1 hybrids, Ictalurus punctatus - Ictalurus furcatus, or NWAC-103 channel catfish, Ictalurus punctatus. Journal of the World Aquaculture Society 41(4):545-554.
Type: Journal Articles Status: Published Year Published: 2010 Citation: Pugliese, N., D. Heikes, and C.R. Engle. 2010. Evaluation of an inexpensive confinement system for growout of channel catfish Ictalurus punctatus stockers. Journal of Applied Aquaculture 22(2):149-156.
Type: Journal Articles Status: Published Year Published: 2009 Citation: Engle, C.R., K. Ruebush, C. Leyva, and J. Trimpey. 2009. The effect of dietary protein level on channel catfish Ictalurus punctatus production characteristics when feeding alternate days in multiple-batch production. North American Journal of Aquaculture 71(2):138-146.
Type: Journal Articles Status: Published Year Published: 2009 Citation: Pugliese, N., D. Heikes, and C.R. Engle. 2009. Evaluation of a barrier confinement system for channel catfish Ictalurus punctatus production. Journal of the World Aquaculture Society 40(3):402-409.
Type: Journal Articles Status: Published Year Published: 2009 Citation: Southworth, B.E., C.R. Engle, and K. Ruebush. 2009. The effect of understocking density of channel catfish stockers in multiple-batch production. Journal of Applied Aquaculture 21:21-30.
Type: Journal Articles Status: Published Year Published: 2011 Citation: Engle, C.R. and G. Kumar. 2011. Biological feasibility and costs of production of large channel catfish Ictalurus punctatus for a speciality product market. Journal of the World Aquaculture Society 42(5):667-675.
Type: Journal Articles Status: Published Year Published: 2011 Citation: Kumar, G. and C.R. Engle. 2011. The effect of hybrid cafish fingerling prices on the relative profitability of hybrid channel catfish. Journal of the World Aquaculture Society 42(4):469-483.

Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: Catfish feed prices in recent years have seen record increases due to increase in price of feed ingredients. This has forced some catfish farms to feed less often in order to meet cash flow needs. Static one-year economic models and analyses may not be adequate to capture the effect of less than daily feeding strategies because understocked fingerlings in multiple batch and smaller stockers in single-batch do not reach market size until the second year of production. A two-year mixed integer-programming model was developed in GAMS to model optimal feeding strategies on catfish farms. Production options considered included the frequency of feeding (every day, every other day, and every third day) and a variety of diets with varying costs. The model selects the profit-maximizing combination of production activities. Options included in the model are: optimal number of ponds, single and multiple batch foodfish production from understocked fingerlings or stockers, on-farm stocker production, on-farm fingerling production activities, stocking various sizes and densities, purchasing and selling fingerlings, stockers, and foodfish, and five farm sizes. PARTICIPANTS: University of Arkansas at Pine Bluff TARGET AUDIENCES: Catfish Farmers PROJECT MODIFICATIONS: No project modifications have been made.

Impacts
Daily feeding is identified as the profit-maximizing feeding strategy in both years. However, by understocking advanced fingerlings (greater than or equal to 60g), farms maximize profit by feeding every other day in Year 1 and daily in Year 2. When feed prices are above $495/mT, every other day feeding becomes the profit-maximizing strategy in Year 2. Results were sensitive to fish prices with Year 2 operations becoming infeasible when fish prices were below $1.43/kg. When operating capital levels fall by 30%, farms maximize profit by feeding every other day in both years.

Publications

Bastola, U., C.R. Engle, A. Haukenes and D. Freeman. 2012. The costs and effects of alternative winter feeding strategies for channel catfish (Ictalurus punctatus) in multiple-batch production. Journal of Applied Aquaculture 24(4):283-298.
Bastola, U. and C.R. Engle. 2012. Economically important production relationships in channel catfish (Ictalurus punctatus)foodfish production: a review. Reviews in Aquaculture 4:1-14.
Sudhakaran, P.O., D. Heikes, C. Engle and S. Pomerleau. 2012. Evaluation of a trawl to estimate the inventory of catfish in commercial ponds. Aquaculture Engineering 48:47-52.
Sudhakaran, P.O., C.R. Engle and D. Heikes. 2012. Evaluation of feed response methods to estimate inventory of catfish in commercial ponds. Journal of Applied Aquaculture 24:32-41.

Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: Increasing feed prices affect production costs for farm-raised catfish. Using low-cost, alternative feed ingredients without compromising fish performance will reduce feed cost. Solvent extracted distillers dried grains with solubles (SE-DDGS) is a locally available by-product that can be a cost-effective ingredient in animal diets. It is the residue after the oil (for human consumption) is solvent-extracted from DDGS, the by-product of ethanol industry. A multi-state pond study was initiated in April 2011, to evaluate alternative (low-cost) feeds containing SE-DDGS as compared with traditional catfish feeds. Diets were fed to channel catfish at University of Arkansas at Pine Bluff (UAPB) and hybrid catfish at the National Warm water Aquaculture Center (NWAC), Mississippi State University, Stoneville, MS. Four diets were evaluated (traditional or alternative 28%- and 32%-protein diets). The two traditional diets (28% or 32% protein) are industry standards while the two alternative SE-DDGS diets (28% or 32% protein) were each formulated with 20% SE-DDGS, supplemental lysine, and contained less soybean meal and corn than traditional diets. Channel catfish fingerlings were stocked in March into five 0.25 ac ponds per diet at 6,000 head/ac (averaging 31 lb/1000, 5 inches) and 1,500 lb/ac of larger, carryover fish averaging 0.50 lb. Ponds were harvested in early October after 186 days of culture. PARTICIPANTS: Mississippi State University and University of Arkansas at Pine Bluff TARGET AUDIENCES: Catfish Farmers PROJECT MODIFICATIONS: No project modifications have been made.

Impacts
Highest yields were obtained from the 28% protein-DDGS diet and lowest from the 32% protein traditional diet (Table1). Yields for fish fed the 32% protein-DDGS and 28% traditional diet were similar and intermediate to the two other diets. FCR of 32% protein-traditional diet (2.02) was significantly higher than for the other diets (1.72). Total feed consumption for the 28% protein-DDGS diet (6.5 tons/ac) was significantly higher than for the other diets (5.9 tons/ac). Two-way ANOVA showed significant effects of both protein amount (28% > 32%) and protein source (DDGS > traditional diet) on gross yield, net yield, carryover survi

Publications

Engle, C.R., M. Thompson, and A. Nanninga. 2011. The effect of varying biomass of carryover fish in multiple-batch catfish (Ictalurus punctatus) pond production. Journal of the World Aquaculture Society 42(6):899-905.
Engle, C.R. and G. Kumar. 2011. The effect of cash flow and credit constraints on financial feasibility and stocking strategies on U.S. catfish farms: a mixed-integer multi-stage programming approach. Aquaculture Economics and Management 15(3):70-91.
Engle, C.R., B. Southworth, P.O. Sudhakaran, and A. Nanninga. 2011. Production and economic effects of in-pond grading of channel catfish. Aquacultural Engineering 45(1):1-8.
Engle, C.R. and G. Kumar. 2011. Biological feasibility and costs of production of large channel catfish Ictalurus punctatus for a specialty product market. Journal of the World Aquaculture Society 42(5):667-675.
Kumar, G. and C.R. Engle. 2011. The effect of hybrid catfish fingerling prices on the relative profitability of hybrid channel catfish. Journal of the World Aquaculture Society 42(4):469-483.
Nanninga, A., C.R. Engle, N. Stone, and A.Goodwin. 2011. Winter feeding of channel catfish Ictalurus punctatus in multiple-batch production. North American Journal of Aquaculture 73:1-8.

Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: The multi-stage integer-programming model was further extended in 2010 to include financial activities of borrowing and repayment in addition to the cash flow constraints for various farm sizes and levels of equity. A pond study was conducted to collect data on production of large sizes of catfish. Results showed that it is possible to produce 3-4 lb catfish with high yields, with a high percentage of catfish in the desired size range, good feed conversion ratios, and estimated the increased costs. PARTICIPANTS: Carole R Engle, Ganesh Kumar TARGET AUDIENCES: Catfish Farmers PROJECT MODIFICATIONS: N/A

Impacts
Sales restrictions (that reduce cash inflow due to a decrease in sales)of only 5% caused small farms to become infeasible (when debt servicing of long-term debt was considered), while the largest farm sizes considered could withstand only a 20% reduction in sales before becoming infeasible. New startup catfish farms would improve cash flow (but not profits) by purchasing large stockers for Year 1, but would need to transition to other management plans to maximize profits in subsequent years. However, use of stockers in Year 1 requires maximum levels on operating capital lines of credit that are much higher than if fingerlings only are stocked. Under-capitalization of catfish farms increases financial risk because the cash flow constraints force farms to operate at sub-optimal levels, leaving them more vulnerable financially to adverse production and/or market conditions. Results of this study confirm suggestions that tight credit for catfish farms may have contributed to recent contractions in the industry.

Publications

Engle, C., G. Kumar and D. Bouras. 2010. The economic trade-offs between stocking fingerlings and stockers: a mixed integer multi-stage programming approach. Aquaculture Economics and Management 14(4):315-331.
Engle, C. and G. Kumar. 2010. The effect of cash flow risk on stocking strategies on U.S. catfish farms: a mixed integer multi-stage programming approach. Aquaculture 2010, Annual Meeting of the World Aquaculture Society, San Diego, California, March 2.
Engle,C. 2010. Is it feasible to grow channel catfish to a size large enough for Delacata? Catfish Channel. June.
Engle, C.R. 2010. Is it feasible to grow channel catfish to a size large enough for Delacata? The Catfish Journal 24(11):5.
Engle, C. and G. Kumar. 2010. How cash flow and credit constraints affect stocking strategies on U.S. catfish farms. Aquaculture/Fisheries Field Day, UAPB, Pine Bluff, AR.
Engle, C.R. 2010. Is it feasible to grow channel catfish to a size large enough for Delacata? Arkansas Aquafarming 27(3):1.
Kumar, G. and C. Engle. 2010. Can You Do Delacata? Aquaculture/Fisheries Field Day, UAPB, Pine Bluff, AR.

Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: The multi-stage integer-programming model developed previously in this project was extended with additional data sets to incorporate cash flow constraints. Cash flow constraints caused smaller farms to be unviable and greater on-farm production of fingerlings and stockers. Financial viability of farms, under cash flow constraints, depends upon the structure of financing options. PARTICIPANTS: Carole R Engle, Ganesh Kumar TARGET AUDIENCES: Catfish Farmers PROJECT MODIFICATIONS: None reported

Impacts
Optimal management of catfish farms under cash flow constraints differs with the size of the farm. Small-scale farms are not viable if cash flow is constrained. Cash flow constraints resulted in greater on-farm production of stocking and fingerlings.

Publications

Nanninga, A. and C. Engle. 2009. Preventing winter weight loss of catfish with implications for preventing VTC. Abstract. Catfish Farmers of America Research Symposium, Natchez, Mississippi.
Nanninga, A. and C. Engle. 2009. Preventing winter weight loss of catfish. Abstract. ARD Symposium, Atlanta, Georgia.
Pugliese, N., D. Heikes, C. Engle and B. Bosworth. 2009. Evaluation of multiple-batch channel catfish production fed four recently-developed commercial diets. Abstract. Aquaculture America 2009, Seattle, Washington.
Pugliese, N., D. Heikes, C. Engle and B. Bosworth. 2009. Evaluation of multiple-batch channel catfish production fed four recently-developed commercial diets. Abstracts. Catfish Farmers of America Research Symposium, Natchez, Mississippi.
Engle, C. 2009. The economics of producing catfish: a review of what we know about stocking densities, sizes, and costs. Abstract. Catfish Farmers of America Research Symposium, Natchez, Mississipi.
Nanninga, A. and C. Engle. 2009. Measuring feed intake for Channel Catfish Ictalurus punctatus during cool weather. Abstract. Aquaculture America 2009, Seattle, Washington.

Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: The multi-stage integer-programming model developed previously in this project was further refined with additional data sets to accommodate varying farm sizes. On the smallest farm sizes (24 & 52 ha), all fingerlings were purchased and all pond produced food fish from purchased fingerlings. The larger farm sizes (102 ha, 172 ha, & 403 ha) shifted to a three-phase production system. This system used some ponds to stock fry to produce 10-cm fingerlings that were then grown to stockers that were then transferred to final food fish growout. The model was robust with respect to pond size and fingerling price, but was sensitive to the feed conversion ratio and survival rates of the stocker phase. PARTICIPANTS: Carole R. Engle, David Bouras TARGET AUDIENCES: Catfish Farmers PROJECT MODIFICATIONS: None reported

Impacts
Optimal management of catfish farms differs with the size of the farm. Smaller-scale farms are more profitable by stocking fingerling catfish directly into food fish growout, while larger farms are more profitable with a three-phase production system. However, financial constraints must be considered before making final management recommendations.

Publications

Nanninga, A. and C. Engle. 2008. Winter feeding channel catfish in multiple-batch production. Aquaculture America 2008, Annual Meeting of the U.S. Aquaculture Society, Orlando, Florida. Abstract.
Southworth, B.F., C.E. Engle, and K. Ruebush. 2008. The effects of understocking density of channel catfish stockers in multiple-batch production. Journal of Applied Aquaculture.
Engle, C. and A. Nanninga. 2008. Preventing winter weight loss in catfish: hunger is not seasonal. Abstract. Aquaculture Field Day, UAPB, Pine Bluff, Arkansas.

Progress 10/01/06 to 09/30/07

Outputs
OUTPUTS: A multi-stage mixed integer-programming model that included production alternatives to produce three different sizes of fingerlings (7.6-cm, 12.7-cm, and 17.8-cm) and six different types of stockers (114-g, 136-g, 176-g, 255-g and 365-g) for various growout alternatives was developed. Results revealed that foodfish production from fingerlings was the most profitable strategy across all farm sizes. Profits were maximized with on-farm production of 12.7-cm fingerlings. The model did not select stocker production as part of the profit-maximizing set of production activities. Of the stocker alternatives included, stocking a 114-g stocker was the most feasible. Sensitivity analyses suggested that the results were robust to changes in catfish prices, levels of capital, market prices of fingerlings, harvesting cost and feed cost. The results however were sensitive to varying levels of feed conversion ratio, growth rates, and to some extent survival rates of stockers. Stockers were selected as the profit-maximizing alternative only at very high survival rates of stockers. PARTICIPANTS: Carole R. Engle, David Bouras TARGET AUDIENCES: Catfish Farmers PROJECT MODIFICATIONS: None reported

Impacts
This study shows that stocking 12.7-cm fingerlings into final growout is the optimal production choice. While some farms have experimented with a three-phase system that includes a stocker phase of production, this analysis indicated that multiple-batch production with 12.7-cm understocked fingerlings maximized profits on catfish farms.

Publications

Bouras, D. and C.R. Engle. 2007. Optimal size of fingerling to understock in catfish growout ponds: an application of a multiperiod integer programming model. Aquaculture Economics and Management 11(2):195-210.
Bouras, D. and C.R. Engle. 2007. Assessing oligopoly and oligopsony power in the U.S. catfish industry. Journal of Agribusiness 25(1):47-57.

Progress 01/01/06 to 12/31/06

Outputs
A multi-period linear programming model was developed to identify the optimal size of fingerling to understock to maximize multi-period returns on a catfish grow-out farm. Growout production alternatives included understocking three different dizes (7.6-cm, 12.7-cm, and 17.8-cm) of fingerlings in multiple-batch production at 15,000 fingerlings per hectare. Fingerlings were produced either with or without thinning at different stocking densities. Results showed that the optimal size of fingerling to understock was 12.7 cm. On-farm production of fingerlings was optimal across all farm sizes but the fingerling production technique selected varied with farm size. Models of larger farm sizes indicated that it is optimal to thin fingerlings, while for smaller farm sizes, producing fingerlings without thinning was optimal. When farm size was treated as an endogenous variable in the farmer's profit-maximizing decisions, the optimal size of a catfish farm was 404-water-ha. Sensitivity analyses suggested that net returns were sensitive to changes in the key parameters of the model (such as interest rates, feed conversion ratios, survival rates, catfish prices, harvesting costs, and the availability of operating capital), whereas the optimal size of fingerlings to understock was robust to variations in the model's parameters.

Impacts
This analysis confirmed the Arkansas Cooperative Extension Program's recommendation to understock with 12.7-cm fingerlings in multiple-batch production. However, this recommendation was extended to identify what mix of on-farm fingerling production strategies (with or without thinning and optimal density) to maximize profits on farms. Enhancing profitability through refinements in production management will assist U.S. catfish farmers to compete with lower-priced imports.

Publications

Bouras, D. and C. R. Engle. 2006. Optimal size of fingerling to understock in multiple-batch catfish farms. Annual Meeting of the U.S. Aquaculture Society, a Chapter of the World Aquaculture Society, Las Vegas, Nevada.