Ganesh Kumar

Technological Advances that Led to Growth of Shrimp, Salmon, and Tilapia Farming

ABSTRACT Aquaculture has been the worlds fastest growing food production sector with an annual growth rate of 8%. Total aquaculture supply increased dramatically from 0.7 mMT in 1950 to 90 mMT in 2012. Growth of the global seafood supply was made possible through adoption of new technologies that brought more control over aquaculture production processes. This review presents evidence of supply-side technological progress that spurred growth in shrimp, salmon, and tilapia production from 1981 to 2012. Greater availability of hatchery-raised post-larvae, better feed formulations, and a shift in preferred shrimp species from Penaeus monodon to Specific Pathogen Free (SPF) Litopenaeus vannamei appear to have been critical technological advances that triggered rapid growth of shrimp farming. Nutritionally balanced feed, use of automated labor-saving equipment, genetic selection programs, and development of vaccines triggered growth of Atlantic salmon production. Diffusion of Genetically Improved Farm Tilapia (GIFT) was a key technological development that fueled rapid growth of tilapia farming. Understanding the technological advances that led to growth of shrimp, salmon, and tilapia farming may provide insights for future growth of other aquaculture species.

FACTORS THAT INFLUENCE FREQUENCY OF PURCHASE OF CATFISH BY U.S. HOUSEHOLDS IN SELECTED CITIES

Increased understanding of the factors that influence the frequency of purchase of catfish (Ictalurus punctatus) by U.S. households would provide guidance for catfish marketing programs. A household survey was conducted to analyze consumer preferences and consumption trends of U.S. farm-raised catfish in Birmingham, Memphis, Chicago, Jackson (MS), New Orleans, Baton Rouge, Little Rock, Oklahoma City, Dallas, Houston, and San Antonio. An ordered probit model was developed to examine the variables influencing frequency of catfish purchase. Household respondents in all cities except Jackson, New Orleans, Oklahoma City, and San Antonio were found to be more frequent buyers of catfish products. Respondents who preferred fresh catfish had a greater likelihood of frequent catfish purchase while buyers of frozen catfish were less likely to purchase catfish frequently. Method of preparation and serving had no influence on catfish purchase frequency. Buyers purchasing from supermarket outlets had a higher probability of being more frequent buyers of catfish products than those who purchase from other market outlets. Product origin labels and vacuum-sealed packaging influenced the frequency of catfish purchase. Caucasians and African Americans were found to be more frequent buyers of catfish products while Hispanics were found to be significantly less frequent buyers of catfish products. Married couples had a greater likelihood of purchasing catfish more frequently than unmarried couples. Age of the respondents as well as number of household members had no significant effect on frequency of catfish purchase. The results from this study support the importance of country of origin labeling, supplying high-quality fresh products, and alternative packaging to enhance sales of U.S. farm-raised catfish in supermarkets.

OPTIMIZING CATFISH FEEDING AND STOCKING STRATEGIES OVER A TWO-YEAR PLANNING HORIZON

Rising costs of feed ingredients in recent years have resulted in record increases in catfish feed prices. Since understocked channel catfish (Ictalurus punctatus) do not reach market size until the second year of production, static one-year economic models and analyses may not be adequate. A previous mixed-integer profit-maximizing model was extended to include a second year to evaluate the effects of varying feeding frequencies on farm management decisions, particularly on adjustments in the second year. Production options considered included frequency of feeding (every day, every other day, and every third day), multiple-batch production from four different fingerling sizes, and single-batch production from three different stocker sizes. Every day feeding was identified as the profit-maximizing feeding strategy on farms using multiple-batch production but unfavorable market prices, high feed prices, and operating capital constraints reduced feeding frequencies. Every day feeding remained the optimal strategy for farms in single-batch foodfish production. Market and capital constraints reduced the scale of farms operating in single-batch foodfish production, but did not change the optimal every day feeding strategy. Farms maximized profits by transitioning from multiple batch to single batch over the two-year period.

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

The availability of credit for aquaculture businesses historically has been problematic in the U.S., but little attention has been paid in the aquaculture economics literature to effects of restricted credit and cash flow deficits on the feasibility and optimal management of fish farms. An existing multi-stage mathematical programming model of catfish production was extended to include cash flow, lending and repayment constraints and activities for various farm sizes and levels of equity. Cash flow constraints affected the optimal management plan for catfish farms, with greater changes occurring in the optimal plans for smaller farms. Smaller farms generally were affected more severely than larger farms by restricted access to capital. 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.

THE ECONOMIC TRADE-OFFS BETWEEN STOCKING FINGERLINGS AND STOCKERS: A MIXED INTEGER MULTI-STAGE PROGRAMMING APPROACH

This paper addresses the economic trade-offs associated with stocking varying sizes of fingerlings and stockers either purchased or produced on farm in catfish growout. A mixed integer-programming model of catfish growout was developed that included seven fingerling, six stocker, and eight foodfish production activities as well as options to purchase and sell fingerlings, stockers, and foodfish. Results showed that profits are maximized on farms of 102 ha and larger by adopting a three-phase production system that includes a stocker phase. On farms smaller than 102 ha, profits are maximized by understocking 17.5-cm fingerlings in multiple-batch. The choice of stocking fingerlings or stockers depended on the efficiency of the stocker production phase; at stocker FCRs of 2.4 or above or survivals less than 40%, stocking fingerlings in multiple-batch was more profitable than the three-phase system with stockers. Additional research is needed to develop farm-level datasets of the variability in key stocker production parameters to expand this model to explicitly evaluate the effect of risk on optimal management strategies.

Effects of 28% Protein Diets Differing in Quality on Channel Catfish Performance, Processing Traits, and Production Economics in a Multi-Batch System

Three 28% protein feeds (premium, standard, or a low-cost diet) were fed to channel catfish in a pond study to compare growth, production, and costs as a follow up to similar work with 32% protein feeds. Twelve 0.1-ha earthen ponds at the University of Arkansas at Pine Bluff (UAPB) Aquaculture Research Station were stocked with carryover fish (0.39 kg mean weight) at 5,860 fish/ha and fingerling catfish (mean individual weight of 15.4 g) at 12,500 fish/ha. Total yield (gross and net) did not differ between fish fed the premium as compared to the standard diet, but that of the premium diet was significantly higher than that of fish fed the low-cost diet. The feed conversion ratio (FCR) did not differ between fish fed the premium and standard diets, but was lower than the FCR of fish fed the low-cost diet. There were no differences found in processing yields among treatments. Given the lower cost of the 28% standard diet and yields equivalent to those of the 28% premium diet, the 28% standard diet was economically preferable to the other diets tested.