bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARISON OF MARGIN OF SAFETY BETWEEN SENSORY SPOILAGE AND ONSET OF CLOSTRIDIUM BOTULINUM TOXIN DEVELOPMENT DURING STORAGE OF MODIFIED ATMOSPHERE (MA)‐PACKAGED FRESH MARINE COD FILLETS WITH MA‐PACKAGED AQUACULTURED FISH FILLETS
Authors: REDDY N.R. , SOLOMON H.M. , RHODEHAMEL E.J.
Published: April 2007

The margin of safety between shelf‐life (onset of sensory spoilage) and potential time to toxin production by Clostridium botulinum type E in retail type packages of fresh marine cod fillets packaged in high barrier film under selected atmospheres [100% air, a modified atmosphere (MA) containing 75% CO2:25% N2, and vacuum] and stored under refrigeration (4C) and temperature‐abuse conditions (8 and 16C) was investigated. Margin of safety data of MA‐packaged marine cod fillets was also compared with MA‐packaged aquacultured tilapia, catfish, and salmon fillets. Sensory spoilage preceded onset of toxin presence for the marine cod fillets packaged in any of the atmospheres and storage temperatures tested. At 4C, none of the marine cod fillets packaged in either atmosphere developed toxin, even 20 days after spoilage, as determined by sensory characteristics. During storage at refrigeration and mild (8C) temperature‐abuse conditions, MA‐packaged marine cod showed a greater margin of safety compared to aquacultured tilapia, catfish, and salmon packaged under the same atmospheres and conditions. Fat content appeared to potentially influence the margin of safety in MA‐packaged aquacultured fresh fish fillets during storage.
PRESENCE OF LISTERIA IN MEXICAN CHEESES
Authors: SALTIJERAL JORGE A. , ALVAREZ VALENTE B. , GARCIA BEATRIZ
Published: April 2007

The presence of Listeria was investigated in ripened cheeses (Chihuahua, Manchego) and fresh cheese (Panela) from street vendors and retail stores in Mexico City. Cheeses were tested for Listeria, pH, NaCl, moisture and fat. Listeria selective cold enrichment was used to recover Listeria from positive samples. Fresh cheese had the lowest pH and NaCl contents and the highest moisture Chihuahua and Manchego cheeses made with pasteurized milk were negative for Listeria. Panela cheese samples were the most contaminated. The presence of Listeria was 65% in fresh cheeses: Listeria murrayi 20%, Listeria inoccua 15%, Listeria grayi 15%, and Listeria monocytogenes 15%. L. monocytogenes serotypes 1/2a, 1/2b and 4b were isolated from positive samples.
INJURY AND SURVIVAL OF AEROMONAS HYDROPHILA 7965 AND YERSINIA ENTEROCOLITICA 9610 FROM HIGH HYDROSTATIC PRESSURE
Authors: ELLENBERG LESLEY , HOOVER DALLAS G.
Published: April 2007

Responses of Aeromonas hydrophila 7965 and Yersinia enterocolitica 9610 to high hydrostatic pressure were investigated in microbiological media and meat. Cultures were pressurized from 51 to 304 megaPascals (MPa) for 15 min in 200 mM sodium phosphate buffer (pH 7.0), tryptic soy broth and radiation‐sterilized ground pork. Trends in pressure response were similar in all three pressure menstrua. A 7‐log10 CFU/g reduction of A. hydrophila in pork resulted from treatment of 253 MPa for 15 min. A 7‐log10 CFU/g reduction of Y. enterocolitica in pork resulted from treatment of 304 MPa for 15 min. Pressure‐induced injury of both pathogens was detected in all pressure menstrua at most pressure levels. No growth of either pathogen occurred in irradiated pork after pressurization of 128–203 MPa for 15 min and storage at 4C for 14 days; however, an upshift to 30C of cold‐stored A. hydrophila in pork resulted in growth after a lag time of approximately 10 h, and an upshift to 30C of cold‐stored Y. enterocolitica in pork resulted in recovery of injured cells within 2 h, and growth after a lag time of 4–6 h. This suggests that temperature abuse (30C) of pressure‐processed pork for greater than 6 h would allow growth and possibly repair of A. hydrophila and Y. enterocolitica which survive following pressure treatment. Although neither the processor nor the consumer would likely abuse the product to such an extent, the results suggest that A. hydrophila and Y. enterocolitica have the ability to repair or grow following pressure treatment in pork.
SURVEY OF APPLE GROWING, HARVESTING, AND CIDER MANUFACTURING PRACTICES IN WISCONSIN: IMPLICATIONS FOR SAFETY
Authors: ULJAS HEIDI E. , INGHAM STEVEN C.
Published: April 2007

To evaluate the safety of current apple growing, harvesting and cider manufacturing practices in Wisconsin, cider manufacturers were contacted in a three‐phase survey. Results revealed that seasonal, small‐scale production was characteristic of the industry. Most cider mills produced less than 5,000 gal/year; only 6% produced more than 20,000 gal/year. Most cider makers used only tree picked apples (86%), inspected apples before washing (94%), washed (93%) and brushed (87%) apples, but only 16% of mills sanitized washed apples. Most mills (92%) sanitized cider making equipment after each use; however, only a few sanitized between custom pressing apples from different customers. Respondents reported that they strived to improve cider safety by pasteurization (43% of all cider), UV light treatment (4%), use of preservatives (30%), and HACCP (17%). For 31% of all cider, however, processors relied solely on refrigeration and/or freezing. These results show that most cider mills practice many steps believed to enhance cider safety, but results also identify procedures that must be addressed to further improve cider safety.
EFFECT OF HEADSPACE OXYGEN AND FILMS OF DIFFERENT OXYGEN TRANSMISSION RATE ON TOXIN PRODUCTION BY CLOSTRIDIUM BOTULINUM TYPE E IN RAINBOW TROUT FILLETS STORED UNDER MODIFIED ATMOSPHERES
Authors: DUFRESNE ISABELLE , SMITH JAMES P. , LIU JIUN NI , TARTE ILSEMARIE , BLANCHFIELD BURKE , AUSTIN JOHN W.
Published: April 2007

Studies were conducted to determine the effect of various levels of headspace oxygen (0–100%, balance CO2) or film oxygen transmission rate (OTR) on the time to toxicity in modified atmosphere packaged (MAP) fresh trout fillets challenged with C. botulinum type E (102 spore/g) and stored under moderate temperature abuse conditions (12C). In all cases, trout were toxic within 5 days, irrespective of the initial levels of oxygen in the package headspace. However, spoilage preceded toxigenesis. Packaging of trout fillets in low gas barrier films, with OTRs ranging from 4,000 to 10,000 cc/m2/day at 24C and 0% relative humidity, also had no effect on time to toxicity in all MAP trout fillets. All fillets were toxic within 4–5 days and spoilage again preceded toxigenesis. This study has shown that the addition of headspace O2, either directly to a package or indirectly by using a low gas barrier film, had no influence on the time to toxigenesis or spoilage. Additional barriers, other than headspace O2 or film transmission rate, need to be considered to ensure the safety of MAP trout fillets, particularty at moderate temperature abuse conditions.
SURVIVAL OF THREE SALMONELLA SEROTYPES ON BEEF TRIMMINGS DURING SIMULATED COMMERCIAL FREEZING AND FROZEN STORAGE
Authors: DYKES G.A , MOORHEAD S.M.
Published: April 2007

This study investigated the survival of three Salmonella serotypes (S. Brandenberg, S. Dublin and S. Typhimurium) on beef trimmings during simulated commercial freezing, frozen storage for 9 months and subsequent abusive slow thawing and refreezing conditions. This was achieved by plating samples monthly and after thawing and refreezing on nonselective Tryptic Soy Agar (TSA) and selective Xylose Lysine Desoxycholate Agar (XLD) and incubating both at 37C for 24 h to determine Salmonella counts, aerobic counts and the presence, if any, of sublethal injury of this pathogen. Two freezing temperatures (−18C or −35C) to simulate slow or rapid freezing respectively, and two inoculation levels (103 cfu g−1 or 105 cfu g−1) were used. Aerobic counts and counts of all the Salmonella serotypes did not change significantly (p > 0.05) during frozen storage or for any of the other treatments applied in this study. This finding was attributed to the insulating nature of the subcutaneous fat layer in this manufacturing cut. These results are important with respect to food safety associated with ground beef processing.
CONSUMER PREFERENCES FOR PATHOGEN‐REDUCING TECHNOLOGIES IN BEEF1
Authors: FINGERHUT KRISTA , ZHANG PING , FOX JOHN , BOLAND MICHAEL
Published: April 2007

Two surveys were conducted by mail to evaluate consumers’ preferences for beef treated by the steam and hot‐water pasteurization technologies, in a comparison with beef treated by irradiation and nontechnology treated “regular” beef. More than 64% of the respondents reported that they preferred ground beef treated by irradiation to that treated by the two pathogen‐reducing technologies. More than 87% of the respondents stated that they preferred ground beef treated by the two technologies to nontechnology treated beef. Sixty percent of the respondents reported that they were willing to pay for beef treated by the two pathogen‐reducing technologies with an averaged willingness‐to‐pay of 0.36/lb over nontechnology treated beef. Compared with their counterparts; women, those having a better self‐reported health status, and those with children at home (≥ 18 years of age) were more likely to report a preference for beef treated by the two heat‐related pasteurization technologies. The income level of the respondents was negatively associated with their preference for beef treated by the two heat‐related pasteurization technologies. The strong consumer preference coupled with willingness‐to‐pay for beef treated by the two pathogen‐reducing technologies, suggest that consumers are willing to bear the cost of using these technologies if beef packers would invest in such technologies as a means of improving the quality of their products.
EFFECT OF IONIZING RADIATION ON BEEF BOLOGNA CONTAINING SOY PROTEIN CONCENTRATE
Authors: SOMMERS C.H. , FAN X. , NIEMIRA B.A. , HANDEL A.P.
Published: April 2007

Soy protein concentrate (SPC), an extender, is a common additive in ready‐to‐eat (RTE) meat products. SPC contains antioxidants that could potentially interfere with the ability of ionizing radiation to eliminate Listeria monocytogenes from RTE meat products. When L. monocytogenes was inoculated into cooked beef bologna emulsion containing 0, 1.75, or 3.5% SPC the gamma radiation D10 values, at radiation doses of 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kGy, were 0.66, 0.68, and 0.71kGy, respectively. Soluble antioxidant power, as determined by the Ferric Reducing Antioxidant Power (FRAP) assay was 1958, 3572, and 5494 mol in bologna emulsion containing 0, 1.75 and 3.5% SPC, respectively. Soluble antioxidant power was not affected by ionizing radiation. SPC did not prevent ionizing radiation induced lipid oxidation as determined by Thiobarbituric Acid Reactive Substance (TBARS) assay. Hunter color analysis of both unirradiated and irradiated bologna slices containing SPC indicated decreased a value as a result of irradiation, while the addition of SPC helped maintain b‐value and L‐value. The inclusion of SPC did not represent a barrier to ionizing radiation pasteurization of fine emulsion sausages for the parameters examined.
EFFECT OF APPLE DECAY PROPORTION ON THE PATULIN, FUMARIC ACID, HMF AND OTHER APPLE JUICE PROPERTIES
Authors: KADAKAL ÇETIN , NAS SEBAHATTIN
Published: April 2007

Starking apples, classified by the decay proportion on the fruit surface as sound, 30, 60 or 100% decayed were used in the production of apple juice. Then patulin, fumaric acid, HMF, pH, brix and Hunter L, a and b values of apple juice samples were determined. Patulin and fumaric acid analysis were done with HPLC. The patulin concentration in juice samples produced with Starking apples that are sound, 30, 60 and 100% decayed ranged between 0.0–15.9 μg/kg, 47.1–500.3 μg/kg, 156.4–2257.5 μg/kg, 54.9–2508.6 μg/kg, respectively. The fumaric acid concentration in the same juice samples ranged between 0.00–0.20 mg/kg, 0.23–0.69 mg/kg, 0.41–2.08 mg/kg and 1.40–4.14 mg/kg. In general, the color values (L, a, b) of the samples produced from 100% decayed apples measured by reflectance with a Hunter colorimeter were low when compared with the others.
VIRULENCE RESPONSE OF A SALMONELLA TYPHIMURIUM HILA:LACZY FUSION STRAIN TO SPENT MEDIA FROM PURE CULTURES OF SELECTED BACTERIA AND POULTRY CECAL MIXED CULTURE
Authors: NUTT J.D. , KUBENA L.F. , NISBET D. J. , RICKE S. C.
Published: April 2007

Virulence gene expression in Salmonella is triggered by a variety of environmental factors including changes in the gastrointestinal environment of birds during different dietary regimes. The objective of this study was to determine if growth of specific microorganisms alters the environmental conditions sufficiently to signal Salmonella Typhimurium virulence response. Spent media was obtained from a Salmonella Typhimurium hilA:lacZY fusion strain, a poultry Salmonella Typhimurium strain, Eschcrichia coli K12, and Lactobacillus caseii Spent media samples were collected after 2, 4, 8 and 24 h of growth in brain heart infusion broth (BHI) and M9 media, β‐galactosidase assays were performed on the samples to determine virulence expression. Virulence response to Salmonella, spent media was 2‐fold greater than Lactobacillus spent media at 4, 8 and 24 h growth (P < 0.05). Virulence expression almost doubled when exposed to Salmonella Typhimurium (NONA) spent media compared to mixed culture spent media at 4 h, and Salmonella Typhimurium (NONA) was significantly higher than mixed culture spent media at 24 h (P < 0.05). Based on these results, it appears that growth of similar bacterial species may alter the composition of rich media sufficiently to influence virulence.
EFFECT OF RAPID COOLING ON THE GROWTH AND PENETRATION OF SALMONELLA ENTERITIDIS INTO EGG CONTENTS
Authors: CHEN HAIQIANG , ANANTHESWARAN RAMASWAMY C. , KNABEL STEPHEN J.
Published: April 2007

Shell eggs were inoculated internally with approximately 10 cells of Salmonella enterica serovar enteritidis (S. enteritidis) and subjected to three different cooling treatments. Eggs were cooled from an initial temperature of 27C to approximately 7.2C. After cooling, eggs were stored at approximately 7.2C for 36 days, or stored at 5.7–9.5C for 30 days plus 6 days at 37C to simulate temperature abuse. Rapid cooling and subsequent storage of eggs at approximately 7.2C inhibited the growth of S. enteritidis in eggs. Slow cooling, and/or temperature abuse promoted growth of S. enteritidis in eggs. The penetration study indicated that rapid cooling and subsequent storage at 7.2C for 30 days did not affect the penetration of S. enteritidis into egg contents. The S. enteritidis isolated from the eggshell with shell membranes was significantly higher (P < 0.05) than from the internal egg contents, indicating that most of the S. enteritidis cells were trapped within the shell pores and/or shell membranes.
FORMULATION OF SOY‐BASED RTE FOODS INFLUENCES RADIATION SENSITIVITY OF LISTERIA MONOCYTOGENES AND POSTIRRADIATION PRODUCT SENSORY PROPERTIES1
Authors: NIEMIRA BRENDAN A. , SOMMERS CHRISTOPHER H. , FAN XUETONG , SOKORAI KIMBERLY J. B.
Published: April 2007

Ionizing radiation can eliminate pathogenic bacteria from ready‐to‐eat (RTE) food products. An outbreak strain of L. monocytogenes was irradiated after inoculation onto (1) three meatless, soy‐based frankfurter products (“Soyl”, “Soy2”, “Soy3”), (2) soy‐based tofu (“Tofu”) and (3) a beef frankfurter product (“Beef”). The D10 was significantly influenced by the substrate: Beef (0.622kGy) = Tofu (0.622 kGy) < Soy2 (0.680 kGy) = Soy3 (0.695 kGy) <Soy1(0.761 kGy). The antioxidant strength of the products also varied significantly, but was not correlated with the D10 values obtained. To determine the sensory impact of irradiation, the products were treated with 1.5 kGy or 3.2 kGy, doses equivalent to 1.9–2.4 or 4.2–5.1 log10 reductions, respectively. These doses significantly decreased redness in Beef and Soy2, and significantly increased redness in Soy3. The maximum shear force of Beef and Soy1 was significantly decreased following irradiation. Product formulation was found to be key in determining the product response to irradiation.
POTENTIAL FOR BACTERIAL GROWTH ON THE FRESH CUT TROPICAL SQUASH, CALABAZA (CURCUBITA MOSCHATA), DURING STORAGE
Authors: MONTVILLE REBECCA , SMITH SARAH , PERDOMO PEDRO , NITZSCHE PETER J. , SCHAFFNER DONALD W.
Published: April 2007

Calabaza (Curcubita moschata) is a tropical squash which is gaining popularity as a specialty crop for agricultural producers in the Northeast United States. It is commonly marketed by being cut in half, wrapped in plastic and may be held unrefrigerated until sold. This method of display is essential for consumer acceptance, yet unrefrigerated storage means that some potential for food safety problems exists. Experiments were conducted to determine the potential for bacterial growth during storage of cut calabaza. Freshly cut calabaza contained between 1.3 and 4.7 log10CFU/g aerobic mesophiles. By 10 h, duplicate counts from some samples exceeded 4 log10 CFU/g. After 24 h of room temperature storage, total aerobic plate counts ranged from 5.2 to 7.7 log10 CFU/g. Rapid bacterial growth on cut calabaza stored at room temperature indicates that these products are highly perishable, and may be able to support the growth of pathogenic bacteria, should they be introduced during the slicing process.
NUMERICAL ANALYSIS OF THE GROWTH OF CLOSTRIDIUM PERFRINGENS IN COOKED BEEF UNDER ISOTHERMAL AND DYNAMIC CONDITIONS1
Authors: HUANG LIHAN
Published: April 2007

The main objective of this study was to develop a numerical technique to solve a set of biologically‐based differential equations used to describe the growth behaviors of bacteria under isothermal conditions in food systems. A 4th‐order Runge‐Kutta method was incorporated to a computer program to solve these equations covering the entire range of bacterial growth, including lag, exponential, and stationary phases. The differential growth models were tested using the spores of Clostridium perfringens inoculated to ground beef and incubated under various isothermal conditions between 17–50C. Results of numerical analysis showed that the differential equations could accurately describe the growth of C. perfringens in cooked ground beef under isothermal conditions.

The differential equations were also used to estimate the growth of C. perfringens in cooked ground beef under four different dynamic temperature profiles: 2‐square waves, exponential and linear cooling. In combination with a secondary kinetic model, the growth of C. perfringens in cooked ground beef under dynamic conditions was accurately estimated. Results showed the differences between the estimated and experimentally observed growth curves under dynamic conditions were generally less than 0.5 log (CFU/g). The methodology developed in this study can be a new approach for the food industry, food retailers and consumers, and regulatory agencies to predict and estimate the bacterial growth in cooked meat products under dynamic temperature abuse and deviation conditions.
PULSED ELECTRIC FIELD TREATMENT OF LIQUID WHOLE EGG INOCULATED WITH SALMONELLA ENTERITIDIS
Authors: HERMAWAN N. , EVRENDILEK G. AKDEMIR , DANTZER W.R. , ZHANG Q.H. , RICHTER E.R.
Published: April 2007

The effects of pulsed electric fields (PEF) on the inactivation of Salmonella Enteritidis inoculated into liquid whole egg (LWE) and on the physical properties and the shelf‐life of LWE were studied. PEF processing conditions were 1.2 mL/s flow rate, 200 pps frequency, 2.12 μs pulse duration, 25 kV/cm electric field strength, and 250 μs total treatment time. The PEF processing caused up to 1 log10 cfu/mL reduction in S. Enteritidis population in LWE. The PEF‐treated samples were subjected to heat at 55C for 3.5 min to inactivate the remaining bacteria without denaturing the LWE. The combination of PEF and heat treatments led to a 4.3 log10 cfu/mL reduction in S. Enteritidis population (P < 0.05) and caused no significant change in viscosity, electrical conductivity, color, pH, and Brix, relative to control samples (P > 0.05). The PEF+55C treated LWE samples presented significantly longer shelf‐life at 4C compared with the control and heat treated samples (P < 0.05).
Degradation of Trifluralin in Seawater When Used to Control Larval Mycosis in Penaeid Shrimp Culture
Authors: Williams Rodney R. , Bell Thomas A. , Lightner Donald v.
Published: April 2007

Treflan (trifluralin, Elanco) is among the compounds used in the treatment of larval mycosis in penaeid shrimp caused by the phycomycetous fungi hagenidium sp. and Sirolpidium sp. Some culturists have reported treatments for these fungi with trifluralin to be ineffective while others have found it to be quite efficacious.

To study losses of trifluralin in seawater systems, experiments were conducted under varying conditions of aeration, lighting, and algal biomass using nominal concentrations of 19.3 to 65.5 ppb trifluralin. There was no detectable loss of trifluralin over a six hour period in seawater mechanically stirred and covered to prevent photodegradation. Under varying conditions of aeration and light, the estimated half‐life of trifluralin ranged from 30 to 138 min. When diatoms were added to the seawater, trifluralin levels dropped to 4% of theoretical within two to three min. These observations confirm the need for a continuous administration for trifluralin to be effective in treating larval mycoses in penaeid shrimp hatching facilities.
Effects of Stocking Density on Growth of Tilapia nilotica Cultured in Cages in Ponds
Authors: Carro‐Anzalotta Antonio E. , McGinty Andrew S.
Published: April 2007

Reported maximum carrying capacities of Tilapia nilotica reared in cages are Iow ranging from 10 to 70 kg/m3. This may be related to total numbers of caged fish reared in a body of water and not simply density per cage volume. An experiment was conducted to demonstrate such effects.

Sixteen cages in a 0.77 ha pond were stocked with T. nilotica at either 250, 500, 750, or 1,000 fish/cage for a total of 12,987 fish/ha. One cage in each of four 0.13 ha ponds was stocked with either 250 or 1,000 fish/cage for a total of 1,923 or 7,692 fish/hectare, respectively. Fish were fed a 32% protein diet at equal rates for 169 days. In the 0.77 ha pond, yield per cage was positively correlated with stocking density, while individual mean weights were negatively correlated with stocking density. However, among equal densities per cage between ponds, fish in the 0.13 ha ponds gained about 26% more than in the 0.77 ha pond. An interaction of the effects of density per cage volume and per pond area may have occurred.
Growth of Tilapia aurea in Seawater Cages
Authors: McGeachin Robert B. , Wicklund Robert I. , Olla Bori L. , Winton James R.
Published: April 2007

Fingerling Tilapia aurea were reared for 90 days in three 1.0 m3 floating cages in seawater (36 ppt) at Lee Stocking Island, Bahamas. Fish stocking density (100, 200 and 400 fish/m3) apparently did not affect growth rate but it appears salinity inhibited growth. Daily weight gain and specific growth rate (G) averaged 0.34 g/day and l.08%/day, respectively, for Tilapia aurea fingerlings. Infection of the Tilapia aurea by Bacillus sp. was associated with a significant number of mortalities. The relatively low growth rate and the high incidence of disease and mortality of Tilapita aures in seawater indicate that it may not be a good candidate for cage culture in full‐strength seawater.
Effect of 17α‐Methyltestosterone Treatment and Withdrawal on Growth and Dietary Protein Utilization of Juvenile Rainbow Trout Fed Practical Diets Varying in Protein Level1,2
Authors: Ostrowski Anthony C. , Garling Donald L.
Published: April 2007

The effects of 17α ‐methyltestosterone (MT) treatment and withdrawal on relative daily gain (RDG), protein gain (PG), productive protein value (PPV), and maximum efficient protein gain (MEPG) of juvenile rainbow trout fed practical diets varying in protein to metabolizable energy (P:ME) ratio were examined over an 18 week period. Two commercially available practical feeds with additions of dextrin and codliver oil were used to formulate diets containing 48% and 32% protein at approximately 320 kcal ME/100 grams with and without 2.0 mg MT/kg of dry diet. MT treated fish were fed hormone supplemented diets for 10 weeks (Phase 1) and hormone free diets for the final eight weeks (Phase 2) of the experiment. Control fish were fed hormone free diets for 18 weeks.

MT treatment increased all growth and efficiency factors of fish during Phase 1. The increase in MEPG values due to MT treatment was more pronounced for fish fed the diet containing 48% protein than for fish fed the diet containing 32% protein. Hormone withdrawal reduced growth and efficiency values of fish to below the level of controls during Phase 2. Greater declines occurred for MT treated fish fed the diet containing 32% protein. No difference was observed between final mean RDC, PG, and MEPG values of fish initially fed MT and control fish calculated for the entire 18 weeks. Hormone withdrawal negated MT stimulated increases in empty carcass (EC) fat and whole body (WB) protein and decreases in EC and WB water contents that occurred in Phase 1. EC ash content was increased due to MT treatment and remained high through the period of withdrawal.
Intensive Culture Potential of Penaeus vannamei
Authors: Sandifer Paul A. , Hopkins J. Stephen , Stokes Alvin D.
Published: April 2007

Tank and pond rearing studies were conducted to assess the potential for intensive culture of Penaeus vannamei in South Carolina. Postlarvae were stocked in intensive nursery tanks at 500/ m2. Growth and survival were compared for shrimp reared in control fiberglass tanks and in tanks with artificial substrates (fiberglass screen). Addition of substrate improved survival (82% versus 58%), but not growth. Juvenile shrimp (mean weight, 1.3 g) from the nursery trial were stocked into 6 m diameter tanks at densities of 10, 20 and 40/m2. Growth rate was inversely related to stocking density, with mean sizes of 33.9, 32.5, and 26.7 g attained at the low, medium, and high densities respectively after 168 days. At harvest, standing crop biomass averaged 225.6, 442.0, and 685.4 g/m2 for the three densities. To further test the intensive culture potential, two 0.1 ha ponds were stocked with hatchery‐reared postlarvae at densities of approximately 40 and 45/m2. The ponds were managed intensively using paddlewheel aerators and water exchange averaging 16–17%/day. The ponds were harvested after 138 and 169 days and yielded 6,010 kg/ha of 16.7 g (mean weight) shrimp and 7,503 kg/ha of 17.9 g shrimp, respectively. Average production was 6,757 kg/ha with a food conversion of 2.51. These data suggest good potential for intensive pond culture of P. vannamei in South Carolina and other areas of the continental United States.
Characteristics of Rice Cultivars with Implications for Crawfish Double Cropping1
Authors: Brunson Martin W. , Taylor Richard W. , Hoff Bert J.
Published: April 2007

Twenty‐five domestic rice (Oryza sativa L.) cultivars were evaluated in a simulated rice/crawfish double cropping system in southwest Louisiana during 1983 and 1984. Wide variation was observed among cultivars in parameters believed to be important for maximizing productivity in such a system. Mean maturity ranged from 99 (Labelle) to 118 days (Starbonnet), while height ranged from 76 (Bellemont) to 130 cm (Della, Nato). Significant differences in grain yield response were observed, with yields ranging from 4,101 (Bluebelle) to 6,665 kg/hectare (Newbonnet). Straw dry matter production varied greatly, from 3,831 (Bellemont) to 9,170 kg/hectare (Della), and was positively correlated with plant height (r = 0.64; P = 0.0001). Ratoon biomass production was negatively correlated with both grain yield (r = ‐0.39; P = 0.0001) and maturity group (r = ‐0.69; P = 0.0001). Plant senescence at grain maturity also varied greatly and appears to be a factor in post‐harvest ratoon capability. Early or very early maturing cultivars with both proven grain production and good ratooning capability appear best suited. Cultivar selection should be based upon individual farm situations and currently employed agronomic practices.
Successful Use of Soybean Meal with a Methionine Supplement to Replace Fish Meal in Diets Fed to Milkfish Chanos chanos Forskal
Authors: Shiau Shi‐Yen , Pan Bonnie Sun , Chen Steve , Yu Hao‐Ling , Lin Sheau‐Ling
Published: April 2007

An experimental feeding trial was conducted to study the feasibility of using soybean meal (SBM) to replace fish meal as a protein source for milkfish feeds containing 30% and 40% dietary protein. The replacement levels were 0%, 33%, 67% and 100%. In each replacement level, methionine was supplemented to the amount that the fish meal control group contained. The experiment was conducted for eight weeks in aquaria that were part of a closed recirculated filtered rearing system. At both dietary protein levels, fish in the 100% replacement groups had significantly (P < 0.05) lower weight gain, feed conversion rate and protein efficiency ratio than that of the groups fed the control diets containing only fish meal. Growth in the 67% and 33% replacement groups did not differ significantly from that of the control groups. The apparent protein digestibility, dry matter digestibility and body composition of fish were similar in all the dietary groups. These data suggest that up to 67% of fish meal in milkfish feed could be replaced by commercial hexane‐extracted soybean meal and a methionine supplement without any adverse effect on milkfish growth and feed conversion rate.
Induced Ovarian Maturation of Penaeus vannamei by Implantation of Lobster Ganglion
Authors: Yano Isao , Tsukimura Brian , Sweeney James N. , Wyban James A.
Published: April 2007

Induction of ovarian maturation in Penaeus vannamei, by implantation of ganglion prepared from female lobster, Homarus americanus, with developing ovaries was investigated under tank culture conditions. Four of six females with thoracic ganglion implants were maturing while only two of thirteen females of the control groups with abdominal ganglion or no implant matured. Two ripe stage V were found 18 days after implantation of lobster's thoracic ganglion. This indicates that ovarian maturation of P. vannumei in tanks can be induced and accelerated by implantation of thoracic ganglion prepared from maturing females of another species. Ovarian maturation may be induced by a gonad‐stimulating hormone, secreted by the thoracic ganglion of maturing females. This gonnd‐stimdating hormone is not species specific in activity in the shrimp and lobster.
Shrimp Yields and Economic Potential of Intensive Round Pond Systems
Authors: Wyban James A. , Sweeney James N. , Kanna Robert A.
Published: April 2007

Three intensive growout trials using Penaeus vunnumei were conducted in round ponds in Hawaii in 1987. A 337 m2 experimental pond was stocked at 100 shrimp/m2 for two trials; a 2,000 m2 commercial prototype pond was stocked at 75/m2 for one trial.

In the experimental pond trials, shrimp survival averaged 88 ± 10% (SE) and feed conversion averaged 2.2 ± 0.2. Growth averaged 1.5 ± 0.3 g/week, yielding 18.2 ± 1.7 gram shrimp in 80 ± 5.5 days. Combined production in the experimental trials was 32,272 kg/ha in 174 days (from stocking of trial 1 to harvest of trial 2). Comparing these results to 1986 results (Wyban and Sweeney 1988), it was concluded that shrimp growth is not affected and production is doubled by increasing stocking density from 45/m2 to 100/m2.

Pooling data from 1986 and 1987, a significant linear regression was obtained when weekly growth of shrimp above four grams individual size was regressed on mean weekly pond temperature: growth = 0.37 * temperature ‐ 8.44, (r2= 0.41; P < 0.01). Multiple regression to examine effects of shrimp size, pond biomass, and shrimp age on the temperature‐growth relationship was not significant.

In the commercial prototype pond trial, survival was 67% and feed conversion was 2.0. Growth averaged 1.4 g/week, yielding 18.1 gram shrimp in 88 days. Production was 9,120 kg/ha. Individual shrimp size distribution at harvest in the commercial pond was similar to experimental pond results, indicating that shrimp growth in the two systems was comparable.

Financial characteristics of a hypothetical 24 pond shrimp farm using these results were determined using an electronic spreadsheet model (hung and Rowland 1987). Feed costs were 40% of total operating costs while postlarvae and labor were 14% and 16% of total operating costs, respectively. Breakeven price (BEP) was far more sensitive to changes in revenuedetermining inputs such as survival and growth than to comparable changes in costdetermining inputs such as feed and postlarvae costs.

Together these results suggest that commercial scale round pond production mimics experimental scale production and that round pond technology has commercial potential.
The Sheepshead Minnow Cyprinodon variegatus—A Major Pest in Experimental Mariculture of the Gulf Killifish Fundulus grandis
Authors: Perschbacher Peter W. , Straw Kirk
Published: April 2007

In an experimental Fundulus grundis hatch and growout system at the Cedar Bayou Mariculture Laboratory, egg‐to‐harvested‐fry survival rate of F. grundis was inversely related to percentage of Cyprinodon variegatus fry present (P < 0.05). Competition for food and space was noted in growout ponds, and high mortalities of F. grundis fry and adults occurred in mixed holding containers as a result of the agonistic behavior of C. variegutus. The hardiness and aggressiveness of the sheepshead minnow, its ability to enter water supplies as small prolarvae, its early sexual maturity, and rapid increase in ponds make it a significant pest in mariculture.

Control measures for C. variegutus include screening incoming water; hand‐sorting contaminated broodstock and fry; and draining, drying, and refilling infested ponds to allow drought‐resistant eggs to hatch, then draining and drying again.
The Economics Associated with Crawfish Production from Louisiana's Atchafalaya Basin 1
Authors: Dellenbarger Lynn E. , Luzar E. Jane
Published: April 2007

Unpredictable water levels for the Atchafalaya River resulting from man's efforts to prevent flooding in South Louisiana lead to an unstable market for Louisiana's annual crawfish production. Empirical models presented show that yields from the basin can be estimated on a monthly basis using bimonthly changes in water level, unemployment rates, and crawfish harvests from ponds. The monthly demand model for basin crawfish yielded a price flexibility of –0.059 and a corresponding price elasticity of –16.94. These empirical results support hypotheses that substitutes for crawfish are available to consumers. Uncertain yields from the basin due to the sort of water level fluctuations documented in this study suggest that investment in this area of the Louisiana crawfish industry will continue to be hampered.
Economic Assessment of Alternative Aquaculture Aeration Strategies
Authors: Engle Carole R. , Hatch Upton
Published: April 2007

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.
Dietary Zinc Requirement of Oreochromis aureus and Effects of Dietary Calcium and Phytate on Zinc Bioavailability
Authors: McClain W. Ray , Gatlin Delbert M.
Published: April 2007

Two experiments were conducted to determine the dietary zinc requirement of fingerling blue tilapia (Oreochromis aureus) and the effects of dietary calcium and phytate on zinc bioavailability. Purified egg white diets containing graded levels of supplemental zinc were fed to fingerling tilapia in triplicate aquaria for 80 days. No overt signs of zinc deficiency were observed; however, scale and bone zinc concentrations of fish fed the various diets were significantly (P < 0.05) affected and increased linearly as dietary zinc increased until plateauing at 20 mg Zn/kg diet and greater. Based on these data, 20 mg Zn/kg of dry diet was determined to be the minimum dietary zinc requirement of blue tilapia. Purified egg white diets containing 20 mg Zn/kg were also supplemented with 0.5 or 2.0% calcium and 0 or 1.5% phytate in a factorial arrangement to determine the effects of these dietary factors on zinc bioavailability. At this level of supplemental zinc, 1.5% phytate significantly (P < 0.05) reduced zinc bioavailability as reflected in scale and bone zinc concentrations; whereas, dietary calcium did not affect zinc bioavailability. Results from this study establish the dietary zinc requirement of blue tilapia and indicate that higher levels of supplemental zinc should be included in practical feeds to compensate for reduced zinc bioavailability caused by dietary phytate.
Growth and Survival of Larval and Postlarval Smallmouth Bass Fed a Commercially Prepared Dry Feed and/or Artemia Nauplii
Authors: Ehrlich Karl F. , Cantin Marie‐Claude , Rust Michael B. , Grant Blake
Published: April 2007

Growth and survival rates of smallmouth bass (Micropterus dolomieui) were compared for fishes reared from larval stages, for three weeks using different feeding regimes. Diets consisted of a commercial dry diet formulated for larval fishes, the dry diet plus Artemia salina nauplii, and Artemia salina nauplii alone. Smallmouth bass on the three diets showed average daily gains of 0.7, 0.7 and 0.5 mm/day and 11.0, 11.4 and 5.2 mg/day, respectively. Condition factors for the three diets were not significantly different (P > 0.05). Mean survival rates were 39, 85 and 77% respectively.
Paddlewheel Effects on Shrimp Growth, Production and Crop Value in Commercial Earthen Ponds
Authors: Wyban James A. , Pruder Gary D. , Leber Kenneth M. , Burzell L.
Published: April 2007

The effects of continuous paddlewheel operation on shrimp growth, yield and crop value were studied in Hawaii. Six 0.4 ha earthen ponds were stocked with Penaeus vannamei at 25 postlarvae/m2. Three ponds served as controls with no mechanical aeration or mixing. Each of the other three ponds had two 1 hp paddlewheel aerators (3.7 kw/ha) running continuously throughout the five month trial (29 April‐8 October 1986). All other management factors were applied uniformly.

Daily water temperature and use were significantly different between treatments. Paddlewheel ponds had lower water temperatures (28.3 vs. 28.5 C) and lower water use (0.8% exchange per day vs. 2.2% exchange per day) than control ponds.

Faster shrimp growth in paddlewheel ponds was evident in week 8. At week 14, mean shrimp body weights and growth rates were significantly greater. Shrimp at harvest were 21.2 ± 2.6 g in paddlewheel ponds versus 15.3 ± 2.6 g in control ponds. Mean shrimp production was 2,852 ± 222 kg/ha in paddlewheel ponds compared to only 2,061 ± 558 kg/ha in controls. Mean crop value was $13,719 per pond per crop for paddlewheel ponds versus $9,111 for control ponds. Hence, paddlewheels afforded an increase of 42% in net crop value after subtracting purchase and operating costs.
Effect of Golden Shiners on Plankton and Water Quality in Ponds Managed for Intensive Production
Authors: Ludwig Gerald M.
Published: April 2007

Water quality variables and plankton were monitored and compared between ponds that were stocked or not stocked with golden shiners in order to determine what changes occur in the plankton community and water quality of ponds managed for intensive production. Ponds with shiners had significantly lower phosphate and carbon dioxide concentrations and lower carbonate alkalinity than ponds without shiners. No significant difference in nitrite, nitrate, ammonia, temperature, secchi disk readings, or turbidity levels was found between the treatments. The standing crop of phytoplankton was nearly twice as great in ponds with fish. Ponds with fish had significantly fewer copepods but more rotifers than fishless ponds. Although the fish were offered a commercial feed with 29.5% protein and 1.5% crude fat at 3% of their biomass daily, they apparently continued to feed on crustacean zooplankton.
Use of the Nematode Panagrellus redivivus as an Artemia Replacement in a Larval Penaeid Diet
Authors: Biedenbach James M. , Smith Linda L. , Thomsen Tamara K. , Lawrence Addison L.
Published: April 2007

Penueus vannumei larvae (P2 through M3) and early postlarvae (<24 h old postlarva) were fed diets consisting of algae‐only, nematodes (Panugrellus redivivus) plus algae or Artemia plus algae. Growth (dry biomass gain) of second and third stage protozoea larvae fed the nematodealgae diet was significantly better than that of larvae fed the Artemia‐algae diet. From the first mysis through the postlarval substage (<24 h old), growth of shrimp fed the nematodealgae diet equalled that of larvae fed the Artemia‐algae diet. All larval substages fed nematodes plus algae accumulated significantly greater biomass than those fed a diet of only algae. Survival and percent metamorphosis of larvae fed nematodes plus algae did not differ significantly from that of larvae fed either Artemia plus algae or algae alone. A nematodealgae feeding regime, which potentially yields growth, survival and metamorphosis equal to that obtained on the standard Artemia plus algae regime, is proposed for P. vannamei.
Stocking Strategies and an Investment Analysis for Producing Penaeus setiferus as a Live Bait‐Shrimp on the Texas Gulf Coast
Authors: McKee David A. , Lawrence Addison L. , Griffin Wade L.
Published: April 2007

An economic and investment analysis was performed to determine the viability of bait‐shrimp farming in Texas. A single pond analysis producing 5–5.5g shrimp always had higher returns above selected cost (RASC) than producing 4–4.5g shrimp. Stocking 0.01g shrimp had a higher RASC than stocking 0.25g, 0.50g or 0.75g shrimp. In the 20 pond analysis, which accounted for marketing considerations, stocking 0.25g shrimp had the highest RASC. The investment analysis, assuming average management, was declared bankrupt by the end of the fifth year. Under “excellent” management the internal rate of return was only 11.7%. It is unlikely that bait‐shrimp farming will become a viable industry in Texas in the near future.
A Standard Reference Diet for Crustacean Nutrition Research. II. Selection of a Purification Procedure for Production of the Rock Crab Cancer irroratus Protein Ingredient
Authors: Castell John D. , Kean J. C. , McCann D. G. C. , Boghen Andrew D. , Conklin Douglas E. , D'Abramo Louis R.
Published: April 2007

Obtaining reliable results from comparative crustacean nutrition studies requires a dietary reference protein which is available world‐wide and is nutritionally optimal for growth and survival. Traditional protein sources include “vitamin free” casein, egg albumin, whole egg protein, soybean protein, and others. These have proven to be inadequate for juvenile lobster (Homrus americanus). Purified rock crab (Cancer irroratus) protein is proposed to be nutritionally superior to casein for inclusion in semi‐purified lobster diets.

Eighteen week feeding trials with juvenile H. americanus were conducted to compare diets containing protein obtained from rock crabs (Cancer irroratus), and produced by several different purification processes with a control diet having casein as its primary protein source. Diets containing purified rock crab protein were found to be superior to the control diet. Among the differently derived purified rock crab protein products, the precooked, isopropanol‐purified was the most effective dietary ingredient.
A Standard Reference Diet for Crustacean Nutrition Research.: IV. Growth of Freshwater Crayfish Cherax tenuimanus
Authors: Morrissy Noel M.
Published: April 2007

Juvenile Australian freshwater crayfish (Cherax tenuimanus) were individually housed in an experimental battery system and fed HFX CRD 84 and BML 81 S, two proposed standard reference diets for studies of crustacean nutrition. The HFX CRD 84 diet was accepted more readily than the BML 81 S diet. After 100 days, mean weight gain of marron fed the HFX CRD 84 diet was significantly greater than that of those fed the BML 81 S diet. Growth rate, measured 118 percent weight pin per ecdysis, declined during three successive 50 day periods. Growth on the proposed reference diets ranged from 16 to 33% of that achieved with pond raised marron of similar age. Both diets may be useful in the development of species specific modifications relative to nutrient composition.
Polyphosphorylated L‐ascorbic Acid: A Stable Form of Vitamin C for Aquaculture Feeds
Authors: Grant Blake F. , Seib Paul A. , Liao Ming‐Long , Corpron Kenneth E.
Published: April 2007

A protected form of vitamin C, L‐ascorbyl‐2‐poly phosphate (APP), was tested for safety and efficacy in fishes. Phosphorylation of the 2‐hydroxyl group protected the 2,3‐enediol of L‐ascorbic acid against oxidation. When APP was added to feed, about 15% of its vitamin C activity was lost during milling and storing 5–7 d at ambient temperature. Stability of APP in pelleted feeds at 25 or 40 C was up to 83 times or 45 times greater than that of ascorbic acid (AA), respectively. In later tests, trout feed mash, steam‐pelleted in triplicate, frozen, and shipped on dry ice before analysis, had 46% loss of AA and no apparent loss of APP.

With 16% milling loss (highest detected in trout feeds assayed in initial tests) and 22% storage loss after 90 d, conservative APP mix rates were estimated. Mixing 153 g L‐ascorbate‐equivalent as APP per metric ton of airdry ingredients (153 ppm) would give 128 ppm in the finished feed after steam‐pelleting and 100 ppm after 60–90 d storage at 40 C.

Low‐temperature extrusion of Oregon‐Moist salmon feed reduced AA slightly. Ascorbic acid oxidized in frozen storage and while thawing and, after 12 h at room temperature, only trace amounts remained. Ascorbyl‐2‐polyphosphate at 0.05 to 0.2 times that of equimolar AA in casein‐base or practical feeds supported long‐term growth and development in rainbow trout and other fishes. Trout feeding trials with practical feeds in actual production regimens documented APP activity at growth rates approaching the maximum for trout farming.

Corrected for greater stability, APP antiscorbutic activity appeared to be comparable to that of AA on a molar‐equivalent basis. Similarly, apparent equimolar activity was inferred from estimated equilibrium levels of liver, kidney, and whole‐body AA and L‐ascorbyl‐2‐sulfate (AS) after prolonged APP use in trout feeds.

Fathead minnow growth and reproduction in egg‐to‐egg life‐cycle tests also confirmed APP safety and efficacy as a stabilized source of vitamin C for feeds.

None of the typical lesions of scoliosis, malformed gill lamellae, and crenulated opercles, nor conditions of poor health, anorexia, and eventual torpor seen in vitamin C‐deficient controls occurred in trout fed APP. No liver pathology was evident in trout fed APP for 252 d at 1.7 to 3.3 times the National Research Council's recommended vitamin C (equivalent) rates.