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Upton Hatch Terrill R. Hanson Walter Zidack Richard T. Lovell Menghe Li 《Aquaculture Economics & Management (Blackwell Science)》2013,17(1):13-22
Abstract Nutritional requirements for catfish (Ictalurus punctatus) feeds based solely on maximizing growth may not lead to the best economic performance. In addition, the choice of protein level may have important implications for dress‐out percentages in the processing sector. Processors may be able to send pricing signals to farmers to improve processing efficiencies. The objectives of this paper are to quantify the economic incentives to use different protein levels in catfish feeds and to investigate the possibility of processor incentives to affect these decisions. Data from research ponds, in conjunction with pricing and cost data, were used to quantify the changes in net returns associated with alternative protein levels. Both experimental results and estimates using commercial practices were developed. In addition these data were utilized in developing price premiums that might be implemented by the processing sector to provide incentives that would result in higher dress‐out percentages and thus greater processing efficiency. In a restricted‐feeding regime, selection of the higher protein feeds resulted in higher net returns, however, in a satiation‐feeding regime, lower protein levels resulted in higher net returns. Specifically, catfish enterprise profitability could be enhanced by feeding a 38% protein ration when fish are fed on a restricted basis whereas, in a satiation‐feeding regime profitability could be enhanced by feeding a 26% protein ration. Results indicate that the potential for a price premium policy that encourages a higher dress‐out percentage might be adopted in the future by the’ catfish processing sector as has been done in other meat processing industries. 相似文献
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Oxygen depletion is a serious problem for the catfish industry, especially as producers attempt to increase their production intensity. Aeration, either emergency or continuous, is the most common method used to address oxygen depletion.
A risk-programming model using Target MOTAD methodology was developed to study the aquacultural producer's aeration decision-making process. Effects of stocking rate, aeration yield response and availability of labor, capital and electricity on the selection of aeration strategy were analyzed.
Continuous aeration with electric paddlewheels was most often selected as the best aeration strategy. However, as farmers become increasingly concerned with financial risk, they apply continuous aeration with pump sprayers first, then no aeration and lastly emergency aeration with tractor-powered paddlewheels. Emergency aeration was only used when: 1) electricity was not available and the producer desired a highly conservative financial strategy, and 2) the relative efficiency of continuous aeration in the field was dramatically reduced from experimental results. 相似文献
A risk-programming model using Target MOTAD methodology was developed to study the aquacultural producer's aeration decision-making process. Effects of stocking rate, aeration yield response and availability of labor, capital and electricity on the selection of aeration strategy were analyzed.
Continuous aeration with electric paddlewheels was most often selected as the best aeration strategy. However, as farmers become increasingly concerned with financial risk, they apply continuous aeration with pump sprayers first, then no aeration and lastly emergency aeration with tractor-powered paddlewheels. Emergency aeration was only used when: 1) electricity was not available and the producer desired a highly conservative financial strategy, and 2) the relative efficiency of continuous aeration in the field was dramatically reduced from experimental results. 相似文献
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Gregory Upton 《CATENA》1983,10(4):383-392
Crabholes are small depressions averaging 50 cm in diameter and 30 cm in depth, and occur on a range of land surfaces in the generally flat alluvial plains extending either side of the Barrier Range in western New South Wales, Australia. At Fowlers Gap, on the eastern side of the range, the alluvial surfaces consist essentially of two types: crusted and non-crusted. Crabholes most commonly occur on non-crusted surfaces, with minimal development on crusted surfaces. The main processes of crabhole formation include shafting in the topsoil and tunnelling in the subsoil, and occur only where a direct path to the subsoil is provided by combinations of vertical cracks. 相似文献
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Upton Hatch Terrill R. Hanson Myung Kon Kim Richard T. Lovell 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):141-150
Abstract Overwintering is a major source of uncertainty for US catfish farmers, particularly decisions on feeding. To address this issue, economic analysis was undertaken using results from pond experiments. Three overwintering strategies (full‐feed, partial‐feed, and no‐feed) for two year classes of catfish were compared. Year 1 fin‐gerlings were 22 g and year 2 fish were 420 g at stocking. Winter feeding was based on temperature and body weight percentages; (1) full‐feeding followed the regime during the November to April period; (2) partial‐fed treatments followed the temperature/body weight regimen only during the months of November, March and April, with no feeding during the coldest months of December to February; and (3) no‐feeding treatments received no feed during the overwinter period. Cost and returns were estimated for each alternative and each alternative was assessed using: (1) overwinter period experimental results, (2) overwinter period experimental results extended through the grow‐out period, (3) overwinter period experimental results extended to minimally acceptable fish sizes, and (4) adjusted estimates to reflect commercial‐scale practices. Sensitivity analyses on feed conversion ratios, stocking rates and fish selling prices were also conducted on commercial‐scale enterprises. Results consistently showed partial‐fed overwinter practices to be most profitable. Secondly, year 1 fish always had higher returns than year 2 fish due largely to the additional overwintering period and associated variable and fixed costs incurred by the year 2 fish production practices. The data upon which this analysis was based do not include the possibility of having a harvest‐sized fish going into the winter period. 相似文献
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Brian L. Nerrie L. Upton Hatch Carole R. Engle R. Oneal Smitherman 《Journal of the World Aquaculture Society》1990,21(3):216-224
Yields of channel catfish in the United States have increased as a result of higher levels of stocking, feeding and aeration. A Cobb-Douglas production function was estimated using survey data from 66 catfish ponds in West-Central Alabama to determine if further intensification of catfish production in West-Central Alabama would be profitable. Feed, capital, stocking rate, and length of production period explained most of the variation in yield. Values of the marginal products for feed, stocking rate and capital were consistently higher than input costs during the study period. Profit-maximizing levels of input use were higher than the levels of inputs used in West-Central Alabama during the study period. Results indicated that more intensive use of production inputs would increase yield and profits. However, careful interpretation of these results requires consideration of non-profit factors such ns cash Row and risk as well as the specific nature of the data used to develop the production relationship. The method utilized in this study can generally be applied to any aquaculture production system, but the recommendation for more intensive input use is specific to the pond data collected for this study. 相似文献
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