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Shrimp production has been one of the most important sectors of aquaculture for the last few decades for both its market value and consumer acceptance. The majority of shrimp feeding protocols in typical production setups rely on a combination of feed trays and predetermined feed plans which do not account for real-time consumption or feed preferences. However, for the last decade, the development of passive acoustic monitoring has allowed a much more direct measurement of shrimp feed intake by capturing and integrating clicking sounds produced by shrimp while eating. Integrating acoustic responses with automated feeding systems has allowed the development of on-demand feeding systems for shrimp. Hence, this technology is a potential tool to help understand feed preferences when the feeding protocol is based on real-time demand for feed rather than predetermined quantities. Building on previous research, the goal of this trial was to use passive feedback acoustic feeders as a tool to evaluate if shrimp prefer diets with different protein sources when given the option to eat as much as requested. A 13-week trial was conducted in 16, 0.1-ha outdoor ponds, stocked at 30 shrimp/m2 and equipped with the AQ1 acoustic feeding system. At day 45, the acoustic system was initiated, and four treatments were assigned with a 35% crude protein diet with different protein sources: all-plant, 8% poultry meal (PM), 8% fish meal (FM), and 12% FM. A second growth trial was conducted in 20, 800-L outdoor recirculating system with similar density (30 shrimp/tank), and shrimp were offered a predetermined feeding rate. We did not find statistical differences in any of the main production parameters. Results of this study indicate that shrimp did not clearly favor a particular diet. This suggests that, irrespective of ingredient matrix, a well-balanced feed will produce suitable growth even when shrimp are allowed to determine their feed intake. The use of acoustic feeders opens the door for nutrition research in which the shrimp are fed on demand. [ABSTRACT FROM AUTHOR]

The latest corn‐based ingredient available in the market today is fermented corn protein concentrate (FCPC), which is expected to perform well in shrimp diets due to its nutritional profile and the probiotic properties of the product. The current study was conducted to evaluate the efficacy of FCPC as a replacement for fish meal (FM) in diets of Pacific white shrimps, Litopenaeus vannamei. Graded levels of FCPC (0, 4, 8, 11, 13 and 15 g/100 g) were used to replace fishmeal (16, 12, 8, 4, 2 and 0 g/100 g) in diet, which was evaluated over a 8‐week growth trial (initial weight 0.17 ± 0.01 g; n = 3). At the conclusion, no significant differences were detected in growth, FCR, survival or haematological parameters of shrimp (p > 0.05). Results reveals the efficacy of FCPC to replace 100% fishmeal at an inclusion level as high as 15%, without compromising the performances of shrimp. Significant increase in total haemocyte count (THC) and astaxanthin level in shrimp in response to the inclusion level of FCPC was assumed to be due to the probiotic properties of fermented corn and due to the availability of bio‐convertible carotenoids in FCPC, respectively. [ABSTRACT FROM AUTHOR]

Shrimp farmers in Alabama are seeking to increase efficiency and intensify production. Semi‐intensive earthen ponds are the traditional production system used by Alabama shrimp farmers; however, there is interest in evaluating intensive pond‐based production systems, such as split ponds. These alternative systems are more intensive and require higher stocking densities to offset capital investment costs required for initial construction and maintenance. Two trials were carried out with Pacific white shrimp Litopenaeus vannamei using on‐levee flow‐through systems (twelve 800‐L tanks per system) at an Alabama shrimp farm to evaluate stocking densities of 29, 88, 176, and 264 shrimp/m2 (trial 1) and higher levels of fish meal (5, 10, and 20%) at a high density of 264 shrimp/m2 (trial 2). Results from trial 1 revealed that as stocking density was increased Pacific white shrimp final weight decreased, while shrimp biomass and feed conversion ratio increased. Survival of Pacific white shrimp at the two highest densities (176 and 264 shrimp/m2) was lower than at the two lowest densities (29 and 88 shrimp/m2). There were no significant differences in performance for Pacific white shrimp offered diets with varying levels of fish meal in trial 2; however, overall survival in trial 2, which was carried out at a high density (264 shrimp/m2), ranged between 47.9% and 65.5%. [ABSTRACT FROM AUTHOR]

A series of trials were conducted with Pacific white shrimp Litopenaeus vannamei, to evaluate the efficiency of two salmon meals as compared to anchovy meal. The basal diet contained 200 g/kg anchovy meal, which was systematically replaced (0%, 50%, 75% and 100%) with salmon meal on an isonitrogenous basis. Another two diets were formulated with a hydrolysed salmon meal to replace 50% and 100% anchovy meal. Each diet was randomly fed to four replicate groups of 25 and 30 shrimp per tank in clear (indoor) and green (outdoor) water trials, respectively. The results showed that growth performance and feed conversion ratio were not statistically different when salmon meal replaced anchovy meal in both trials. However, when hydrolysed salmon meal was used to replace 100% of the anchovy meal, growth performance of the shrimp significantly decreased. The four kinds of fish meal (anchovy, salmon by‐product meals and menhaden) were evaluated in an ingredient digestibility trial using the 70:30 replacement technique. In general, dry matter, energy, protein and individual amino acids digestibility of salmon meal were significantly higher than those of menhaden and anchovy meal. Results of this study demonstrated that salmon meals are a good protein sources which can replace anchovy meal. [ABSTRACT FROM AUTHOR]

Substitution of fish meal (FM) as a protein source in aquaculture diets is required to reduce cost and promote a sustainable industry. Potential protein sources include a range of traditional products from agricultural production such as plant or animal proteins. However, there are also a number of manufacturing coproducts, including bacterial dried fermented biomass (DFB,) for which there is an increased interest. Hence, the objective of this study was to evaluate DFB as a replacement for FM in practical diets for Florida pompano,Trachinotus carolinus. Four diets were prepared in which different levels of FM (15%, 10%, 5%, and 0% of the diet) were replaced with DFB (0%, 4.27%, 8.54%, and 12.82%) on an iso-nitrogenous and iso-lipidic basis, to contain 40% crude protein and 10% lipid. A 10-week growth trial was conducted in a recirculating system consisting of 12 indoor 1.0 m3tanks, stocked with 20 juvenile pompano (mean initial weight 8.1 g) per tank. There were no significant differences in final weight (64.5 g−79.5 g), survival (81.7%–96.7%), percent weight gain (711.6%–879.0%), FCR (2.1–2.0), or thermal-unit growth coefficient (0.1013−0.1149), regardless of the levels of dietary FM or DFB tested. Based on these results, it is recommended that DFB can be included up to 12.8% in practical diets for Florida pompano without significantly reducing growth performance. The response to higher levels of DFB inclusion should be evaluated. [ABSTRACT FROM PUBLISHER]

Abstract: Two growth trials were designed to evaluate varying levels of taurine in diets for white seabass (WSB), Atractoscion nobilis. All diets were formulated to contain 40% protein and 10% lipid with a fixed level of fish meal (FM) and soybean meal (SBM). Trial A tested a series of six practical diets with 0.0, 0.1, 0.2, 0.3, 0.4, 0.5% taurine supplementation at the expense of glutamic acid, and a seventh diet with 0.5% cystine supplementation instead of taurine. Trial B was designed to test higher inclusion levels (0.2–1.6%) of taurine over six diets, while a seventh diet contained 1.6% taurine but no methionine supplement. In Trial A, the increased inclusion of taurine resulted in significantly improved final weight ranging from 14.6 to 26.6g, TGC ranging from 0.074 to 0.120, and feed efficiency from 68.2 to 111.9%. The supplementation of cystine to the diet did not result in an improvement in growth, indicating the synthesis of taurine from cysteine decarboxylation is inadequate in WSB. Similarly, in Trial B significant improvements in performance were observed with increasing taurine supplements, albeit variation in the data was higher. Final weight ranged from 23.6 to 29.7g, TGC ranging from 0.111 to 0.130 and feed efficiency from 75.6 to 81.4%. The diet with taurine supplement but without methionine showed a decrease in growth, suggesting that methionine was then limiting. Datasets from both trials were combined, and a saturation kinetics model was used to determine a dietary requirement of 0.99% of the diet (R2 =0.8770). Based on these results, white seabass have a dietary requirement for taurine presumably due to a limited ability to synthesize it. [Copyright &y& Elsevier]

Abstract: The objective of this study was to demonstrate the feasibility of four diets formulated to contain high levels of soybean meal in combination with either poultry by-product, fish meal, distiller''s dried grains with solubles, or pea meal in production diets for L. vannamei. Outdoor ponds and tanks were utilized to evaluate the response of the shrimp over the culture period. The pond production trial was conducted in 0.1-ha ponds stocked with juvenile shrimps (mean weight±S.D., 0.038±0.004g) at 35shrimpm−2 and cultured under standardized pond production conditions for 18weeks. The same dietary treatments plus a commercial reference diet were offered to shrimp (initial weight of 2.1g) maintained in outdoor tanks (800L) over a 12-week period. The results for the pond study demonstrated that final production ranged between 5054 and 5265kgha−1, mean final weight varied from 15.98 to 16.28g, survival ranging from 86.6 to 93.7%, and FCR was between 1.32 and 1.37. There were no differences (P≥0.05) or notable trends in shrimp production variables among different test diets. Shrimp reared in the outdoor tanks confirmed these findings. Average final weights ranged between 18.53 and 19.00g, survival varied from 97.3 to 98.7%, and FCR was between 1.30 and 1.33. The results from the outdoor tank study also showed no differences (P≥0.05) in final weight, survival, or FCR among test diets. Diet containing partial fishmeal showed no benefit on growth performance of L. vannamei comparing with diets containing high levels of soybean meal in combinations with poultry by-product, distiller''s dried grains with solubles or pea meal. Therefore, these studies demonstrated that practical shrimp feeds containing no fish meal had no negative impact on growth performances of L. vannamei. [Copyright &y& Elsevier]

Abstract: The apparent digestibility coefficient (ADC) of energy of various vegetable feed ingredients with relatively high levels of carbohydrate was determined for Florida pompano, Trachinotus carolinus. A practical fish meal and soybean meal based reference diet was formulated to contain 54% protein, 11% lipid, and 1% chromic oxide. Using the 70:30 replacement strategy seven test diets were produced that included corn grain, sorghum grain, whole wheat flour, wheat bran, wheat middlings, full fat rice bran, and defatted rice bran. Each of the diets were offered to juvenile pompano (111.6g mean weight) maintained in a recirculation system. After one week of conditioning to the diets, fecal samples were obtained by manually stripping the fish. Chromium content and gross energy of the diets and fecal samples was then determined and digestibility coefficients calculated. The ADC of energy of the evaluated feedstuffs showed a wide variation, ranging from 8.2% for wheat middlings, to 55.4% for whole wheat flour. Knowing the contribution of common vegetable feed ingredients to the digestible energy content of production diets is critical to achieve cost-effective formulations that may lead to a reduction in the overall feeding cost of Florida pompano production, providing useful information to improve feed formulations for this species. [ABSTRACT FROM AUTHOR]

Two feeding trials were conducted to begin development of a practical soy-based diet for white seabass . The first trial was designed to provide initial data on the efficacy of practical soy-based diets. Three diets and a commercial reference diet were evaluated. Research diets were 42% protein and 12% lipid, with varying protein sources: fish meal (FM), FM plus solvent-extracted soybean meal (SBM), or FM plus soy protein concentrate (SPC). Final weight (14.1-17.2 g), percent weight gain (307.2-401.8%), and feed conversion ratio (FCR; 1.0-1.2) followed similar trends, with fish offered the FM-based diet significantly outperforming the other dietary treatment groups. There was no significant difference between soy-based diets and the commercial reference diet, and no significant differences in survival due to dietary treatments were observed. The second trial was designed to evaluate varying levels of FM replacement with SPC in a series of four diets containing 42% protein and 12% lipid. The basal diet contained 40% FM and 24.6% SBM as primary protein sources. The FM was then reduced to 30, 20, and 15% of the diet using SPC as the replacement protein. Final weight (27.1-36.5 g), percent weight gain (69.0-116.6%), and FCR (1.5-2.4) followed similar trends, with performance decreasing as FM level was reduced. In general, each incremental reduction in FM resulted in significant reductions in final weight and percent weight gain and significant increases in FCR. Results from these initial trials on white seabass are encouraging because the poor response was most likely due to a nutrient imbalance or palatability problem, which can be corrected, as opposed to an allergic response. Given that the open formulations performed similarly to the commercial feed, these simple formulations can be used as a starting point for the development of practical diets for white seabass. [ABSTRACT FROM AUTHOR]

The replacement of marine proteins with vegetable proteins or terrestrial animal byproducts in aquaculture diets has been gaining momentum. This study examines the viability of replacing fish meal in shrimp production diets with alternative protein sources (combinations of vegetable proteins) in inland low salinity waters of west Alabama. The test diets were formulated to contain 36% protein and 8% lipid. The basal diet contained 10% fish meal. The fish meal was then replaced (on a weight to weight basis) with poultry meal (PM), pea meal or distiller's dried grain with solubles (DDGS). Two separate experiments (laboratory trial and farm trial) were devised to test the efficacy of the diets for Litopenaeus vannamei reared in low salinity waters. The laboratory trial was conducted at the E. W. Shell Fisheries Research Station in Auburn, Alabama, USA, whereas the farm trial examined the same diets in an outdoor flow-through system at a low salinity shrimp farm in west Alabama. Results indicate no significant differences in shrimp growth, weight gain, survival or feed conversion ratio among dietary treatments, suggesting that PM, pea meal and DDGS can serve as alternatives to fish meal as a protein source for shrimp reared in low salinity environments. [ABSTRACT FROM AUTHOR]

Abstract: Future use of animal protein sources in shrimp feeds is expected to be considerably reduced as a consequence of increasing economical, environmental and safety issues. Of main concern has been the use of expensive marine protein sources, such as fish meal. Hence, shrimp research has recently focused on the development of practical feeds with minimal levels of fish meal and alternative, lower cost protein sources. To determine shrimp capacity to use practical feeds with plant proteins as replacement ingredients to animal protein sources, an 81-day growth trial was conducted in an outdoor tanks system, using juvenile (0.74 g) Litopenaeus vannamei. Experimental treatments included four diets with varying levels of fish meal in the diet (9, 6, 3 and 0%) in combination with 16% poultry by-product meal, a plant based feed containing 1% squid meal, and a commercial reference feed. Feeds were commercially extruded and offered as sinking pellets designed to contain 35% crude protein and 8% lipids. Mean final weight, percent weight gain, final net yield, feed conversion ratio and survival were evaluated. Final values for these parameters ranged from 17.4 to 19.5 g, 2249–2465%, 564.4–639.0 g m−3, 1.07–1.20 and 83.3–89.2%, respectively. Evaluation of production parameters at the end of the study demonstrated no significant differences (P ≥0.05) among any of the experimental treatments. These results indicate that fish meal can be replaced with plant protein sources in diets including 16% poultry by-product meal without affecting shrimp growth and production. In addition, results demonstrate that good performance can obtained by shrimp fed a plant protein based feed (solvent extracted soybean meal, corn gluten meal and corn fermented solubles) in combination with 1% squid meal. Although results with the primarily plant based diet are encouraging, further evaluations are recommended to allow the removal of the remaining marine ingredients. [Copyright &y& Elsevier]

Abstract: Increasing economical and ecological concerns regarding the use of fish meal in diets for marine shrimp have led to the development of replacement strategies where soybean meal has received ample attention. Most studies evaluating these strategies have been carried out under laboratory conditions which greatly differ from production conditions in ponds. This study evaluated a fish meal replacement strategy using vegetable protein sources in practical feeds for marine shrimp reared in ponds. Juvenile Pacific white shrimp (Litopenaeus vannamei) (0.03 g) were stocked into 16 0.1-ha low-water exchange ponds and reared over an 18-week period. Four commercially extruded diets formulated to contain 35% crude protein and 8% lipids were evaluated. These diets included varying levels of fish meal (9, 6, 3, and 0%) which was replaced by a combination of increasing levels of soybean meal (32.5, 34.9, 37.2 and 39.6% respectively) and corn gluten meal (0.0, 1.7, 3.2, and 4.8% respectively) to replace the protein originating from fish meal. At the conclusion of the experimental period, there were no significant differences (P ≥0.05) in shrimp production among the test diets. Mean final yield, final weight, feed conversion ratio and survival values ranged from 5363–6548 kg ha−1, 18.4–20.7 g, 1.38–1.12 and 84.0–94.0%, respectively. Although not significant, as higher levels of plant protein sources were included in the diets, the economic analysis showed a general increase in the partial gross returns of shrimp production. Results from this study demonstrate that fish meal can be completely replaced using alternative vegetable protein sources in practical shrimp feeds without compromising production and economic performance of L. vannamei reared in ponds. [Copyright &y& Elsevier]

The replacement of fish meal with soybean meal in fish diets has met with varying degrees of success. Quite often, poor responses to high soybean meal diets are due to a reduced palatability of the diet when fish meal is removed. Recent work has demonstrated that poultry by- product meal can be used as a substitute for fish meal in practical diets for juvenile red drum, (Sciaenops ocellatus), indicating it may have favorable palatability characteristics for this species. The present research was designed to evaluate the replacement of menhaden fish meal with solvent-extracted soybean meal in practical diets containing 20% poultry by-product meal and formulated to contain 44% protein and 10% lipid. Test diets were adjusted for phosphorus and methionine content to ensure that minimal dietary requirements were maintained. The response of red drum (mean initial weight 179 g) to diets containing fish meal ranging from 40 to 5% of the diet, as well as the response to a low fish meal diet supplemented with krill hydrolysate were evaluated over a 14-week growth period. Final weights (percent gain) ranged from 588 g (237.8%) to 651 g (258.5%) with feed conversion efficiencies ranging from 62.1% to 69.9% and protein conversion efficiencies ranging from 27.8% to 30%. No significant differences (P > 0.05) were observed for diet intake, feed conversion efficiency, protein conversion efficiency, intraperitoneal fat ratio, or weight gain. Significant differences in protein intake and the hepatosomatic index were observed. The present findings suggest that fish meal can be reduced to 5% of the diet by replacing it with solvent-extracted soybean meal as well as methionine and phosphorus supplements. Although diets without poultry by-product meal were not tested, it is presumed that the poultry meal enhanced the palatability of the diets, allowing the replacement of fish meal with soybean meal. [ABSTRACT FROM PUBLISHER]

The use of a co-extruded soybean poultry by-product meal with egg supplement was evaluated as a substitute for fish meal in a practical diet formulated to contain 32% crude protein and 8% lipid. The co-extruded product was substituted for menhaden fish meal on an iso-nitrogenous basis and offered to juvenile Litopenaeus vannamei (mean initial weight±standard deviation, 1.13±0.06 g) over a 6-week period. Inclusion levels ranged from 0% (30 g fish meal/100 g diet) to 100% replacement (0 g fish meal/100 g diet). A fifth diet was formulated to contain no fish meal and 1 g krill meal/100 g diet. Furthermore, a commercial shrimp feed was included in the study to allow for a commercial reference. At the conclusion of the growth trial, survival, final weight, percent weight gain and feed efficiency (FE) were not significantly different among treatments. The inclusion of krill meal did not appear to improve attractability or palatability of the diet. Co-extruded soybean poultry by-product meal with egg supplement appears suitable as a substitute for fish meal in L. vannamei diets. [Copyright &y& Elsevier]

Aquaculture production is an important part of the global food supply and has equaled or surpassed fisheries production as the main source of aquatic foods. Aquaculture is a resource intensive practice that can use large amounts of land, water, energy, and cause pollution and degradation to the local environment. Intensive production practices have been criticized in the past for causing environmental harm; however recent studies have suggested that resource use may decrease with increasing production intensities at the farm level. Here we used a conceptual farm to access the impact of a few key production parameters on land, water, and energy use. A series of calculations were conducted at various production intensities with modifications made to the type of feed used and water exchange rate. The resulting relationships were then modeled with production intensity. Additionally, the effect of various feedstuffs on embodied resource coefficients was examined through varying protein and carbohydrate feedstuffs. Land and water use were found to have an asymptotic relationship with production intensity, with the most important factor in land use being production intensity and the most important factor in water use being the water exchange rate. Energy use was found to be higher with a diet that has fish meal as a protein source and at higher water exchange rates. The most land intensive diets used for shrimp contained high fish meal with rice as carbohydrate feedstuffs (0.550 ha/tonne). The most water intensive diet was no fish meal with corn as a carbohydrate (1863 m3/tonne), and the most energy intensive diet was high fish meal with corn as a carbohydrate (11.73 GJ/tonne). The results herein suggest that intensifying shrimp aquaculture could save resources based on per tonne of production basis. [Display omitted] • Intensive shrimp farms save land compared to extensive shrimp farms. • Water exchange is the driving factor with regards to water use at shrimp farms. • Energy use increases, but plateaus with intensification. • There are tradeoffs with different feed ingredients and production systems. [ABSTRACT FROM AUTHOR]

Abstract: A 12-wk feeding trial was conducted with juvenile (0.6±0.3g) Pacific white shrimp, Litopenaeus vannamei, to evaluate the need for cholesterol supplements in plant based diets for shrimp reared in an outdoor system in the presence of natural foods. The basal diet was formulated with no fish meal and targeted crude protein levels of 35%. Five levels of supplemented cholesterol (0, 0.02, 0.04, 0.06, and 0.08%) resulted in diets analyzed to contain 0.061, 0.076, 0.110, 0.125, and 0.155% cholesterol. In addition, two levels of phytosterol supplements (0.05, 0.1%) were evaluated. Mean final weights and growth ranged from 19.13 to 20.20g and 1.52 to 1.61g/week, respectively. One-way ANOVA showed a significant difference (P ≤0.05) among shrimp fed diets containing the various levels of cholesterol, with diets containing ≤0.076% total cholesterol producing smaller shrimp. No significant differences were detected among treatments with respect to survival, yields or FCR. Performance did not significantly improve when shrimp were offered diets supplemented with 0.06% (0.125% total cholesterol) or higher levels of cholesterol. This would suggest that the cholesterol requirement for L. vannamei grow-out lies somewhere between 0.076 and 0.11%, however, a regression analysis predicted the cholesterol requirement for maximum growth to be 0.15% of the diet. Performance of shrimp fed the diets with two levels of phytosterol supplementation was compared to those fed the basal diet (no cholesterol supplementation) and the highest level of cholesterol (0.08%) supplementation. Mean final weight and growth rates were significantly different (P ≤0.05) with the mean final weights of the lowest phytosterol inclusion (0.05%) and the 0% cholesterol supplementation being similar, 19.03 and 19.13g, respectively and the highest levels of phytosterol (0.1%) and cholesterol (0.08%) supplementation being similar, 20.18 and 20.20g respectively. Likewise, the growth per week showed a similar trend, with the two lower levels of ingredient inclusion resulting in a growth rate of 1.52g/week and the higher levels achieving a growth rate of 1.61g/week. Survival, yield, and FCR were not significantly different between treatments. [Copyright &y& Elsevier]

Two 10-week growth trials and digestibility trials were conducted to assess the efficacy of various cottonseed products in practical diets for the Florida pompano Trachinotus carolinus. In trial 1, a basal diet containing 150 g/kg of fishmeal (FM150) was modified by the iso-nitrogenous replacement of fishmeal (FM) with cold pressed cottonseed flour (CSF) resulting in diets containing 100 g/kg (FM100), 50 g/kg (FM50) and 0 g/kg (FM0) of fishmeal. To determine if lysine was limiting in the FM0 diet, two additional diets were developed using a high lysine corn protein concentrate (FM0-LCPC) or a crystalline source of lysine (FM0-CL). In trial 2, the basal diet was formulated to contain 457.0 g/kg of soybean meal (SBM) and 150 g/kg of poultry by-product meal (PBM), the other three diets were made by replacing SBM on an iso-nitrogenous and iso-lipidic basis with varying cottonseed flours (CSF) which included cottonseed flour (CSF), gossypol-extracted cottonseed flour (ECSF), and glandless cottonseed flour (GCSF). In trial 1, results showed that the use of up to 196 g/kg of CSF with a lysine supplement does not inhibit growth performance of the fish. In trial 2, no significant differences were observed in growth performance of the fish maintained on the various diets. Although gossypol was detected in the livers of fish offered diets with gossypol, no differences were observed in the cells of the liver samples or organization of the liver cells amongst any of the treatments. After each growth trial, apparent digestibility coefficients for dry matter (ADMD), energy (AED), and protein (APD) were determined for primary ingredients. In the first digestibility trial, no significant differences were observed with regard to digestibility coefficients for FM, CSF, and corn protein concentrate (CPC). In the second digestibility trial, no significant differences were observed on ADMD and AED for the ingredients GCSF, CSF, and ECSF. However, the APD values for ECSF were found to be significantly lower than those values of GCSF and CSF. Results of this study provide support that cottonseed products are acceptable for use in practical diets for Florida pompano. Statement of relevance In this study, we assessed the efficacy of various cottonseed products in practical diets for the Florida pompano. These findings will be useful because the feed producers need the growth and digestibility data of the cottonseed products as an alternative ingredient to use in the diet formulation. The conclusions in this manuscript provide valuable information which researchers and feed producers need to use the cottonseed products in diets of this species. [ABSTRACT FROM AUTHOR]

The inclusion of chemoattractants has been investigated to improve the attractability and palatability of plant-based shrimp diets. A more recent approach utilizes passive acoustic monitoring (PAM) to record the sounds (clicks) emitted by shrimp during feeding activity allowing the identification of behavioral responses related to the diets. In the present study we automatically identified click signals in PAM recordings at sampling frequency of 192 kHz. This methodology was applied to evaluate the efficiency of three chemoattractants (krill meal, squid meal and fish hydrolysate) added to a basal all-plant diet on the acoustic feeding behavior and food consumption of naive (without acclimation) and non-naive (acclimated to the diets) Litopenaeus vannamei. Five diets were used: basal all-plant diet (AP, negative control) and its modifications to contain 20 g/Kg of krill meal (AP+KM), 20 g/Kg of squid meal (AP+SM) and 40 g/Kg of fish hydrolysate (AP+FH); a diet with 120 g/Kg fishmeal (FM) was used as a positive control. Ten shrimp (6.8 ± 0.6 g; mean ± SD) were stocked per aquarium (70 L) in a clear water recirculation system (30 aquaria, five diets with six replicates). The food consumption and acoustic activity were evaluated simultaneously in each aquarium over a 30-min period during two consecutive days for each trial, naive and non-naive shrimp. Strong positive relationships (r = 0.78–0.81; P < 0.001) were found between food consumption and total number of clicks emitted by naive and non-naive shrimp. Overall, the inclusion of the chemoattractants to the plant-based diet had a positive effect improving acoustic feeding behavior and food consumption for naive and non-naive L. vannamei. In particular, the response of non-naive shrimp to chemoattractants was markedly increased, and the highest clicking activity was attained by using krill meal (AP+KM), followed by fish hydrolysate (AP+FH). The new analytical method proved to be a useful alternative approach for studying shrimp feeding behavior, also indicating the potential of PAM to forecast feed intake and improve efficiency of feed management. • A novel analytical method based on click detection was applied to study shrimp feeding behavior. • Audio sampling rate (192 kHz) was double of previous studies with passive acoustic monitoring (PAM) of L. vannamei. • Chemoattractants added to all-plant diet had a positive effect on shrimp food consumption and feeding behavior. • Results reinforce the benefits of using PAM to investigate shrimp feeding activity. [ABSTRACT FROM AUTHOR]

Abstract: The present study aims to identify the limiting amino acids in low fish meal, soy-based diets in juvenile white seabass. Two 8-week trials were conducted. The first trial evaluated three diets containing 36, 18 and 9% fish meal in the diet (FM36, FM18, FM9, respectively), with the last two diets being supplemented with methionine and taurine. In the second trial, seven diets were formulated, including a high (36%) fish meal diet (HFM, similar to FM36) and five diets with medium (18%) fishmeal levels. These included an unsupplemented diet (MFM) and four with increasing levels of methionine (+M, +2M) and taurine (+2MT and +2M2T) supplementation. An additional diet was formulated with soy protein and poultry by-product meal to completely replace fish meal (PM). In trial 1, fish fed the FM18 diet grew significantly faster than fish fed the FM36 and FM9 diets. In trial 2, fish fed the +2M2T diet grew better than fish fed any other diets, and feed efficiency was highest in fish fed the +2M2T and PM diets. Fish fed the unsupplemented MFM diet had the lowest growth and feed efficiency. Methionine supplementation (+M and +2M) had a limited but significant effect on growth performance compared to MFM-fed fish. Fish fed the PM diet showed similar growth as those fed the +2MT and commercial diets, but was lower than +2M2T diet. Across both trials, growth rate was highly correlated with dietary taurine, except in diets containing less than 18% fish meal, i.e., diets PM and FM9. Both of these diets had equivalent or superior dietary taurine levels compared to diets +2M2T and FM18, but resulted in significantly poorer growth. This suggests that taurine is the first-limiting nutrient in feeds containing at least 18% fish meal while methionine was marginally deficient. In diets containing lower levels of fish meal however, methionine and taurine supplementation is ineffective; hence another (undetermined) nutrient became first-limiting. Additional research is necessary to identify this limiting nutrient, as well as determine the specific taurine requirement of WSB. [Copyright &y& Elsevier]

Four growth trials were conducted to evaluate the effects of fishmeal replacement with various levels of soybean meal (SBM) and poultry byproduct meal (PBM) on growth performance in practical diets for juvenile and sub-adult red snapper, Lutjanus campechanus. In addition, the need for taurine and palatability enhancement (krill meal) were evaluated in the high SBM, low fishmeal diet. Across the trials, ten diets were formulated to contain 36% protein and 10% lipids. All diets except for one included a taurine supplement of 1%. A supplement of 5% krill meal was added as an attractant to one of the low fishmeal and high SBM diets to explore potential palatability issues associated with plant-based proteins. No statistically significant differences were found between the performance of the basal diet and the PBM replacement diets, indicating that PBM is a suitable replacement for fishmeal in red snapper diets. On the contrary, a clear negative linear relationship was observed with increasing levels of SBM replacement. The reduced growth performance of high SBM inclusion diets is unlikely to be due to palatability issues, as no significant difference was observed between the performance of the high SBM diet with krill meal and an identical diet without krill meal. The significant reduction in growth observed in snapper fed a diet lacking a taurine supplement indicates that red snapper have a taurine requirement that is limiting at low (0.2%) levels. Gut samples were taken from fish that received the SBM diets to determine if reduced growth performance could be attributed to inflammation. However, no statistically significant difference was observed, indicating that reduced growth was not necessarily the result of a hypersensitivity reaction. Further investigation will be necessary to determine the optimal taurine requirement and required dietary supplements to improve the performance of low fishmeal feed formulations. • Fishmeal was replaced with soybean meal (SBM) and poultry by-product meal (PBM). • 100% fishmeal replacement with PBM showed no difference in growth of red snapper. • Negative linear relationships between growth and increasing levels of SBM in diets • The addition of krill meal as an attractant did not improve growth performance. • Red snapper have a taurine requirement. [ABSTRACT FROM AUTHOR]