Diets For Pacific White Shrimp Research Articles

Effects of dietary nucleotides supplementation on growth, total haemocyte count, lysozyme activity and survival upon challenge with Vibrio harveyi in pacific white shrimp, Litopenaeus vannamei

The use of soybean meal (SBM) as replacement for fish meal (FM) in diets for Pacific white shrimp (PWS), Litopenaeus vannamei, involves a negative impact on the health of PWS. Dietary nucleotides modulate the immune response; therefore, they might be able to counteract this effect by enhancing PWS immunity. Based on this hypothesis, this study was aimed at evaluating the effects of nucleotide supplementation in PWS receiving diets in which FM had been partially replaced by SBM. A 70-day feeding trial was conducted to evaluate the effects of dietary nucleotides on PWS growth performance, protein levels and retention rate, total hemocyte count (THC) and lysozyme activity. Ten experimental diets were formulated. The control diet included 10% FM and 43% SBM. Another diet was formulated by reducing FM to 5% and by increasing SBM up to 50%. The rest of diets included 0.05 or 0.1% nucleotide supplementation with varying degrees of FM replacement by SBM. A total of 900 PWS post larvae with an average initial body weight of 4.24 ± 0.03 g were randomly assigned to ten study groups, with six replicates per group and 15 PWS per aquaria tank. After the performance trial, disease resistance was evaluated in a 7-day challenge test with Vibrio harveyi at the consistent concentration of 105 CFU mL−1. Nucleotide supplementation led to significantly higher THC and lysozyme activity (P < 0.05) and a significantly increased PWS survival in the V. harveyi challenge test (P < 0.05). No significant differences were found between groups regarding growth parameters or protein analyses (P > 0.05). In conclusion, the present study shows a positive impact of nucleotide supplementation on immune response and disease resistance against V. harveyi. Nucleotides could therefore be used as functional dietary ingredients, especially in PWS which receive diets with FM replacement by plant-protein sources.

Evaluation of aflatoxin and fumonisin in the diet of Pacific White Shrimp (Litopenaeus vannamei) on their performance and health

The objective of this study was to evaluate the effect of aflatoxin and fumonisin on the performance and health status of Litopenaeus vannamei juveniles and the efficiency of an anti mycotoxin additive (AMA). A 42-day trial with of six treatments and four replicates: (CONT - diet without mycotoxins or AMA, CETX - diet with the addition of AMA, AFLA - diet contaminated with 1067.8 ng/g Aflatoxins, FUMO - diet contaminated with 1715.3 ng/g Fumonisins, AETX - diet with addition of Aflatoxins and AMA; FETX - diet with addition of Fumonisins and AMA). The replicates were randomly assigned to 24 aquaria with individual biological filters. Water quality was monitored for temperature, pH, dissolved oxygen, nitrogenous compounds, alkalinity, hardness and salinity. At the end of the experiment all animals were counted and weighed individually to determine survival (%), mean final weight (g), biomass gain (g) and specific growth rate (%). The hepatopancreas of 16 animals per treatment were collected to perform histopathological evaluation. For water quality variables there is no differences among treatments. Survival was high (>90%) with no significant differences between treatments. For all other performance parameters significant differences were observed due to contamination. Feeding shrimp an aflatoxin or fumonisin contaminated diet resulted in reduced weight, biomass gain, and specific growth rate. The addition of an anti mycotoxin additive compensated these losses and even resulted in significant better growth for the fumonisin contaminated group. Histological damage was observed in all contaminated treatments, although the damage was less pronounced in the treatments containing the anti mycotoxin additive. Results from this study suggest that aflatoxins and fumonisins negatively affect growth and performance of shrimp and that this tested anti mycotoxin additive has proven efficacy in compensating these losses.

Replacement of fish meal with Methanotroph (Methylococcus capsulatus, Bath) bacteria meal in the diets of Pacific white shrimp (Litopenaeus vannamei)

Methanotroph (Methylococcus capsulatus, Bath) bacteria meal is a kind of bacterial protein meal (BPM) with an excellent nutrition profile. This study evaluated the effects of replacing fish meal (FM) with BPM on growth, antioxidant capacity, intestinal morphology, and gut microbiota of Pacific white shrimp (Litopenaeus vannamei). A basal diet was formulated to contain 25% FM, then 15, 30 and 45% of FM was replaced with BPM, which were identified FM, BPM15, BPM30, and BPM45 diets, respectively. Triplicate groups (40 shrimp per replicate) of shrimp (0.88 ± 0.01 g) were fed the test diets to apparent satiation four times daily for 7 weeks. There were no significant differences in growth performance among four groups. Malondialdehyde content and anti-oxidative enzymes activity in hepatopancreas were significantly increased with increasing BPM levels. For intestinal histology, the circular muscle layer thickness was significantly increased in BPM45. The mucosal folds height of shrimp fed BPM45 was significantly higher than those fed BPM15. The width of mucosal folds in BPM15 and BPM30 was significantly reduced comparing with FM. Transmission electron microscopy results showed that intestinal microvilli was impaired and endoplasmic reticulum stress was present in shrimp fed BPM45 diet. However, dietary BPM improved the diversity of intestinal microbiota, and more beneficial microbiota such as Pseudoalteromonas, Ruegeria, and Lactobacillus, as well as less harmful microbiota such as Vibrio were found in the gut of BPM45. A 12-day challenge study with Vibrio parahaemolyticus showed that shrimp fed diet BPM15 had a significantly lower mortality throughout the challenge trial. To conclude, BPM replacement of fish meal did not affect growth performance and feed utilization of shrimp. The high dietary inclusion of BPM increased the oxidation level in the hepatopancreas of shrimp and BPM was able to increase the height of the mucosal folds, improve the gut microbiota structure and increase the disease resistance of shrimp.

Soybean meal sourced from Argentina, Brazil, China, India and USA as an ingredient in practical diets for Pacific white shrimp Litopenaeus vannamei

Soybean meal (SBM) from China, Argentina, Brazil, the USA and India was collected to evaluate their performances in the diet of Pacific white shrimp. SBM samples were analysed for proximate composition, amino acid profiles, sugars, fibres, macro and micro minerals. A growth trial was conducted using SBM-based test diets (350 g kg−1 protein and 80 g kg−1 lipid), and a digestibility trial was carried out from digestibility diets formulated by mixing the basal diet and test ingredients (70:30) on a dry matter basis. Significantly higher growth (as standardized Thermal growth coefficient) was observed in shrimp fed SBM from China over Brazilian SBM. However, growth performances of shrimp fed SBM sourced from USA, Argentina and India were not different to that of Chinese and Brazilian SBM. No significant differences were observed for apparent dry matter, energy and protein digestibility coefficients (<0.05) of SBM among the countries. The differences observed in the ingredient chemical profile of SBM between countries were not reflected in the growth and digestibility data of shrimp. These results highlight the importance of multiple variables influencing the biological value of soybean meals and that simplified generalizations such as country of origin, poorly define the quality of an ingredient.

Nannochloropsis spp. as Feed Additive for the Pacific White Shrimp: Effect on Midgut Microbiology, Thermal Shock Resistance and Immunology

Simple SummaryWe evaluated Nannochloropsis spp. as a feed additive for the Pacific white shrimp by testing for thermal shock resistance, immunology, and midgut microbiology. Nannochlorpsis spp. are rich in Eicosapentaenoic acid, an n-3 fatty acid. This study demonstrated that the inclusion of these microalgae in the diet increased shrimp resistance to thermal shock and stimulated shrimp immune defense.This work aimed to evaluate Nannochloropsis spp. as feed additive in the diet of Pacific white shrimp for their effect on midgut microbiology, thermal shock resistance and immunological parameters. Initially, the digestibility of the microalgae meal was assessed, and the apparent digestibility coefficient (ADC) was determined. The ADC was, in general, high in lipids (78.88%) and eicosapentaenoic fatty acid (73.86%). Then, Nannochloropsis spp. were included in diets at four levels (0, 0.5, 1 and 2% inclusion). The shrimp were reared in 500 L clear water tanks containing 20 shrimp per tank with an initial weight of 6.05 ± 0.06 g and fed four times a day. Shrimp fed with supplemented diets containing Nannochloropsis spp. (0.5 and 2%) presented higher resistance to thermal shock when compared to the non-supplemented group (control). Shrimp fed with 1 and 2% of algae inclusion had a higher production of reactive oxygen species (ROS) when compared to other treatments. No statistical difference was observed in the immunological parameters and microbiology of the intestinal tract. Thus, the inclusion of Nannochloropsis spp. in shrimp diets at 0.5 and 2% levels increases resistance to thermal shock and ROS production in shrimp.

Protein‐rich product recovered from brewer's spent grain can partially replace fishmeal in diets of Pacific white shrimp,Litopenaeus vannamei

A protein-rich product (PP) with 46% protein and less than 1% fibre was recovered from brewery's spent grain. This study aimed to investigate the effects of replacing dietary fishmeal with PP on the growth, feed utilization efficiency and nutritional composition of Pacific white shrimp, Litopenaeus vannamei. The control diet (PP0, containing 35% fishmeal) was compared with four isonitrogenous (44% crude protein), isolipidic (10% crude fat) and isocaloric (20 kJ/g) test diets, PP10, PP30, PP50 and PP70, which were formulated using PP protein to replace 10%, 30%, 50% and 70% of fishmeal protein. Sextuplicate groups of shrimp (averaging 1.10 g) were fed each of the five diets for 8 weeks. The results showed that up to 50% of fishmeal replaced with PP did not negatively affect the shrimp survival, growth performance, feed utilization efficiency, or the protein content and amino acid profile of shrimp. However, replacing 70% of fishmeal protein with PP protein negatively affected the percent weight gain and specific growth rate of shrimp, although the shrimp survival rate and feed conversion ratio were not affected.

The replacement of fish meal with fermented soya bean meal or soya bean meal in the diet of Pacific white shrimp ( Litopenaeus vannamei )

The present study evaluated the effects of replacing fish meal (FM) with soya bean meal (SM) or fermented soya bean meal (FSM) on growth, nutrient utilization, digestive enzyme activity and intestinal histology of Pacific white shrimp. The basal diet (control) contained 18% FM, and then, FM in basal diet was replaced by 1/6 (17%), 1/3 (33%) and 1/2 (50%) by the inclusion of SM and FSM, referring to SM17, SM33, SM50, FSM17, FSM33 and FSM50 respectively. The shrimp (3.0 g) were fed one of the seven diets for 8 weeks. The results showed that the control group had the highest weight gain (WG) (653.8%) and the lowest feed conversion ratio (FCR) (1.61). SM33, SM50 and FSM50 groups showed significantly lower WG, crude protein (CP) digestibility, hepatopancreatic protease, amylase activity and higher FCR than the control (p < .05). The villi height of SM33, SM50 and FSM50 groups and the intestinal wall thickness of SM groups and FSM50 group were significantly lower than those of the control (p < .05). In conclusion, fish meal (18%) in white shrimp diet could be replaced by 1/6 (17%) and 1/3 (33%) with SM and FSM respectively. Fermented soya bean meal could replace more fish meal than soya bean meal did.

Hydrolysed salmon meal as a replacement for salmon meal in practical diets for Pacific white shrimp ( Litopenaeus vannamei )

A series of growth, feed stability and consumption trials were conducted to evaluate the efficacy of salmon by-product in practical diets for Pacific white shrimp, Litopenaeus vannamei. This included a salmon by-product meal (Salmon meal: SM) and a silage hydrolysate (hydrolysed salmon meal: HSM). The basal diet containing 120 g/kg SM was incrementally replaced (0. 25, 50, 75, 100%) by HSM to produce five test diets used in two trials. A sixth diet was included which evaluated gelatin supplementation (trial 1) or pH neutralization (trial 2). In trial 1, each diet was produced using two processing conditions (laboratory extruded and formed with meat grinder) and offered to shrimp in a clear water system. The results demonstrate that up to 50% of the SM can be used to replace with HSM; however, further increases resulted in reduced performance of shrimp. The addition of gelatin reduced leaching but there was limited effect of processing on leaching. There were no detectible effects of pH adjustment of the diets. Results indicated that the growth performance of shrimp has not influenced by HSM up to 60 g/kg to replace 50% of the SM in practical diets; however, higher levels resulted in significant decrease in performance.

Evaluation of differently processed soybean meal products as ingredients in practical diets for Pacific white shrimp Litopenaeus vannamei

Numerous advanced soybean meal (SBM) products are available in the market today, which were produced through modified or improved methodologies from the traditional solvent extraction procedure, to reduce or eliminate the antinutritional factors and improve bioavailability of nutrients. Despite the higher manufacturing cost, inclusion levels of these new SBM products into fish feed formulations can still be limited due to the secondary quality characteristics caused during processing. Hence, this study was designed to evaluate the effect of differently processed SBM, on growth performances of pacific white shrimps (Litopenaeus vannamei). The growth trial was conducted with test diets formulated with two sources of solvent‐extracted (SESBM44 and SESBM49), enzyme‐treated (ETSBM), fermented SBM (FSBM) and alcohol‐extracted soy protein concentrate (SPC) as the primary protein source (650 g/kg). As per the statistical analysis, diets incorporated with SESBM44, SESBM49 and ETSBM yielded a significantly higher growth performance and lower FCR. Results of this study infer that the traditional solvent‐extracted SBM perform equally well as enzyme‐treated SBM, whereas reduced performances of the shrimp offered fermented SBM and alcohol‐extracted soy protein concentrate might be due to reduced nutrient digestibility, palatability or other nutrient shifts caused by processing.

Replacement of fish meal with defatted silkworm (Bombyx mori L.) pupae meal in diets for Pacific white shrimp (Litopenaeus vannamei)

This study evaluated the effects of replacing fish meal (FM) with defatted silkworm pupae meal (SPM) on growth, diet digestibility, antioxidant capacity, hepatopancreas histology and molting process in Pacific white shrimp (Litopenaeus vannamei). A basal diet was formulated to contain 24% FM, then 25, 50, 75 or 100% of FM was substituted with SPM referred to as FM, SPM25, SPM50, SPM75 and SPM100 diets, respectively. Quadruplicate groups (36 shrimp per replicate) of shrimp (0.2 ± 0.02 g) were fed the test diets to apparent satiation three times daily for eight weeks. No significant difference (P > .05) in growth performance could be found among FM and SPM groups. Apparent digestibility coefficients of dry matter, gross energy and phosphorous were significantly improved by SPM inclusion. Serum antioxidant parameters including total antioxidant capacity and malondialdehyde concentration were beneficially influenced by SMP inclusion. Higher number of B-cells and lower number of E-cells were detected in hepatopancreatic tubules of SPM100 group compared to the other groups. Moreover, total replacement of FM triggered separation of basal membrane and greater interstitial spaces between the hepatopancreatic tubules. Molting time significantly decreased when FM was entirely replaced with SPM. Also, chitin deacetylase activity was enhanced in SPM100 group, but β-N-Acetyl-d-glucosaminidase activity, and expression of ecdysteroid receptor and retinoid X receptor remained unchanged. To conclude, the entire replacement of FM with SPM did not influence shrimp growth, and its beneficial impacts were found on diet digestibility, antioxidant capacity and molting time. However, the substitution level is recommended to be restricted to 75% as total replacement led to shrinkage of hepatopancreatic cells.

Utilization of date seed meal in the diet of Pacific white shrimp (Penaeus vannamei): growth performance, body and fatty acid composition, biochemical parameters, and tolerance of salinity stress

Current study aimed to examine the effectiveness of date seed meal (DSM) in the diet of Pacific white shrimp (Penaeus vannamei). Shrimp were fed on diets containing different amounts of DSM including 0, 50, 100, 150, and 230 g/kg for a period of 8 weeks. Growth parameters and body proximate composition showed no significant differences among treatments (p > 0.05). Similarly, no notable differences were observed in hemolymph biochemical parameters in shrimp fed with different amounts of DSM compared with the control group (p > 0.05). The contents of whole body polyunsaturated fatty acids (PUFAs) including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and total n-3 in P. vannamei fed diet containing 100 g/kg DSM were significantly greater than control treatment (p 0.05). Altogether, the results of this study showed that DSM could be utilized as a cheapest source of carbohydrate in the shrimp diet without depressive effects on its performance.

Evaluation of soybean meal from different sources as an ingredient in practical diets for Pacific white shrimp Litopenaeus vannamei

Solvent extracted soybean meal (SBM) is generated using different varieties of soybeans grown under a range of conditions and then processed at different crushing plants. Due to its competitive cost and availability, it is a popular plant-based protein source for shrimp feed formulations. However, there is limited information about effects of variations in the nutritional composition of soybean meal have on performances of shrimp. Hence, the present study was designed to determine the effects of different soybean sources on the growth performances of Litopenaeus vannamei. Two growth trials were conducted with iso-nitrogenous and iso-lipidic (350 g/kg protein and 80 g/kg lipid) test diets formulated with 25 sources of soybean meal. Trial one incorporated 14 treatments including a soy-based diet containing 517 g/kg SBM (eight replicates) and this soy source was then replaced with 13 different soybean sources (four replicates per treatment). The second trial used the same basal diet and 11 different sources of soybean meal (Total 12 diets) with five replicates per treatment. Both growth trials were conducted with a stocking density of 10 shrimps/aquarium in a semi-closed recirculating system and the initial weight of shrimps for trials 1 and 2 were 0.23 g ± 0.02 and 0.67 g ± 0.02 respectively. During the two trials, shrimp were fed four times/day assuming a FCR of 1.8, over 42 days for trial 1 and 35 days for trial 2. Results indicated that there are differences among sources of soybean meal for standardized percentage TGC. Diet 21 that contained SBM4550 had the largest value for TGC whereas the lowest value for TGC was observed for shrimp fed diet 17 that contained SBM45536. According to the statistical analysis that was used to interpret the growth performance data from the complete chemical profile of the SBM, phosphorous, phytate-phosphorous and total phytic acid levels had positive correlations (p < 0.005) with TGC whereas raffinose (p = 0.086) had a negative correlation with TGC. Results of this work indicates phosphorous, phosphorous in phytic acid and total phytic acid and raffinose are important components in SBM that may have significant effects on the growth performances of pacific white shrimp.

Replacement of fish oil in plant‐based diets for Pacific white shrimp, Litopenaeus vannamei, by stearine fish oil and palm oil

Stearine fish oil (SFO) and palm oil (PO) have emerged as promising alternatives for the replacement of fish oil (FO) in aquafeeds. This study evaluated the replacement of FO with alternative oils in practical diets for Litopenaeus vannamei. In a clear brackish water study (14.1 g/L) utilizing shrimp (0.29 ± 0.02 g, initial weight), FO was replaced by SFO at inclusion ratios of 100:0, 75:25, 50:50, 25:75, and 0:100 (FO:SFO) and PO as 90% of FO. After 55 days, no significant differences (p &lt; 0.05) in final weight, growth, or survival of shrimp were observed. A second trial (8 weeks) in low‐salinity water (2.1 g/L) with shrimp (0.92 ± 0.02 g, initial weight) evaluated diets with 100% FO, 100% SFO, 90% PO, 90% soybean oil (SO), or 90% flaxseed oil (FXO) as a replacement for FO and four commercially produced diets with 2% of FO, SO, PO, or FXO. One treatment received half rations of the commercial FO diet, and one treatment was based entirely on natural productivity. Results show that the fatty acid profiles of the tail muscle conformed to the lipids of the feed, and highly unsaturated fatty acids (HUFAs) were preserved. Following 8 weeks of culture, there were no significant differences in production performance.

Chitooligosaccharide supplementation in low-fish meal diets for Pacific white shrimp (Litopenaeus vannamei): Effects on growth, innate immunity, gut histology, and immune-related genes expression

This study evaluated the effects of supplementing chitooligosaccharide (COS) in low fish meal (FM) diets on growth, immune response, intestine and hepatopancrease histology, and expression of inflammatory and immune-related genes in Pacific white shrimp (Litopenaeus vannamei). A basal diet was formulated using FM and soybean meal (SM) as primary protein sources and considered as a high FM (HFM) diet, then a low FM (LFM) diet was prepared by substituting 50% of FM with SM and supplemented with 0, 0.3, 0.6, 0.9, 1.2 or 1.5 g COS kg−1 diet (LFM, COS3, COS6, COS9, COS12 and COS15 diets). Each diet was fed to quadruplicate groups of shrimp (0.9 g) to apparent satiation three times daily for eight weeks. At the end of the experiment no significant changes in growth and survival rate were observed among treatments (P > 0.05). FM replacement led to significant (P < 0.05) reduction of serum lysozyme activity and significant improvements were obtained by adding 0.3 or 0.6 g kg−1 COS to the LFM diet. A significant decrease in nitric oxide synthase activity was found in LFM group and no beneficial effects could be achieved by COS application. LFM group showed higher hepatopancrease superoxide dismutase and glutathione peroxidase activities than HFM group and further enhancements were obtained by COS application. Hepatopancrease total antioxidant capacity and alkaline phosphatase activity decreased in LFM group and COS supplementation improved their values. Expression of lysozyme, crustin, Pen3 and proPo genes were significantly up-regulated in hepatopancrease of groups received 0.3–0.9 g COS kg−1 diet. FM substitution enhanced the expression of HSP70 and inflammatory genes such as AIF and TNF in hepatopancrease and intestine, and COS administration at a moderate level down-regulated their expression level. Remarkable enhancement in intestinal fold height was obtained by inclusion of 0.3 or 0.6 g COS kg−1 diet compared to the group received LFM diet. Shrimps fed HFM and COS containing diets exhibited higher number of E-cells within their hepatopancrease tubules than the LFM group. The findings in this study clearly demonstrated that COS could enhance non-specific immune response and antioxidant activity, and ameliorate the negative impacts of high SM diets on gut and hepatopancrease health in pacific white shrimp. The optimum inclusion level of COS seems to be 0.3–0.6 g kg−1 of diet.

Nutritional evaluation of an improved soybean meal as a fishmeal replacer in the diet of Pacific white shrimp,Litopenaeus vannamei

Nutritional evaluation of an improved soybean meal as a fishmeal replacer in the diet of Pacific white shrimp,<i>Litopenaeus vannamei</i>

Utilization of fermented soybean meal for fishmeal substitution in diets of Pacific white shrimp (Litopenaeus vannamei )

Utilization of fermented soybean meal for fishmeal substitution in diets of Pacific white shrimp (<i>Litopenaeus vannamei</i> )

Optimum Replacement Value of Fish Silage for Protein Source in Pacific White Shrimp Diets

Chemical and biological evaluations were undertaken to determine nutritive value of acid fish silage (FS) as a dietary protein source in the diet of Pacific white shrimp (Litopenaeus vannamei). Proximate composition, and amino acid profile of FS were determined for chemical evaluation; amino acid profile of FS was employed to predict its nutritive value against shrimp requirements for essential amino acids (EAA). Three biological evaluations of FS were conducted: (1) the attractability of the FS diets were compared with diets containing no FS; (2) a growth trial of 60 days was performed to determine the effects of replacing protein sources in the diet with FS, on the growth performance of the shrimp; (3) shrimp from the growth trial in the second biological experiment were evaluated to determine whether or not FS in the diet resulted in enhanced immune response against Vibrio parahemolyticus. Experimental diets were prepared containing 5 levels of FS replacing the combined fish meal and Acetes meal (kept at a constant ratio of 1:3): 0% FS (control), 12.5%, 25%, 37.5% and 50% FS replacement. For results of the chemical evaluation, the computed EAAI of FS was 98.5 indicating a well-balanced profile. In the attractability test using a custom-made setup, results showed that shrimp (1-2 g) were significantly more attracted to the diet containing 50% FS replacement than any other diet; the control and the other experimental diets were statistically similar in attractability. In the growth trial experiment, shrimp (average weight =0.01g) were fed diets of the same composition as that used for the attractability test. Results showed that weight gain (WG) and specific growth rate (SGR) of the FS-supplemented groups were significantly higher than the control group; however, 25% FS group did not significantly differ from that of the 37.5% FS. Feed conversion ratio (FCR), protein efficiency ratio (PER) and survival rate did not differ significantly among experimental groups. In the V. parahemolyticus challenge test, optimum FS replacement for immune enhancement was estimated to be 24.5% FS using a broken line model. In conclusion, the findings revealed that FS could serve as a feeding stimulant at 50% FS replacement. Likewise, FS could serve as an immunostimulant against V. parahaemolyticus in L. vannamei.

Use of Porcine Meal in Plant‐based Practical Diets for Pacific White Shrimp, Litopenaeus vannamei

AbstractTwo growth trials were conducted to evaluate and confirm the efficacy of a porcine meal (PM) with high protein content (&gt;90%) as an alternative feed ingredient in commercial‐type feed formulation for Pacific white shrimp, Litopenaeus vannamei. Six experimental diets were formulated for the two growth trials. The first five diets contained increasing levels (0, 1, 2, 4, and 6%) of PM as a replacement for soybean meal in a plant‐based diet with low inclusion level (6%) of fish meal (FM). The last experimental diet was produced utilizing 4.2% PM to completely replace FM. In Trial 1, shrimp (1.5 g initial mean weight, 20 shrimp/tank, n = 4) were offered test diets for 6 wk in a semirecirculation system. At the end of Trial 1, shrimp fed with the diet containing 6% PM exhibited significantly enhanced weight gain (WG), feed conversion ratio (FCR), and survival compared to those fed with the diet devoid of FM. As survival was poor across all treatments and different densities could mask growth results the trial was repeated. In Trial 2, shrimp (0.85 g, 15 shrimp/tank, n = 4) were offered diets for 6 wk. Dietary supplementation of PM at 6% significantly improved WG, FCR, and apparent net protein retention in contrast with the treatment devoid of FM, confirming the same trends in Trial 1. No significant difference was detected in protein, lipid, moisture, and mineral profiles of whole‐body shrimp as well as survival across all the treatments. Results of this study indicate that PM is a good high protein source in shrimp feeds, which can be included up to 6% in the low FM‐based diet without compromising the growth of shrimp.

Antioxidant activity and apparent digestibility of amino acids of three macroalgae meals in the diets of Pacific white shrimp (Litopenaeus vannamei)

The antioxidant activity of meals, growth performance, dry matter, crude protein and amino acid apparent digestibility coefficients (ADC) were determined for three macroalgae in Pacific white shrimp juveniles: Gracilaria vermiculophylla , Dictyota dichotoma and Ulva lactuca . For the digestibility determination, test diets included 15% of the test ingredients and 85% of a control diet supplemented with 1% chromic oxide. The amino acid content in the ingredients, diets and feces were analyzed using HPLC. In general, nutrient digestibility values were far higher in the diets with macroalgae meals than in the control diet. In conclusion, diets with the macroalgae U. lactuca and G. vermiculophylla in particular showed high antioxidant activity, high amino acid digestibility and improved Litopenaeus vannamei growth.

Evaluation of a fish meal analogue as a replacement for fish meal in practical diets for Pacific white shrimp Litopenaeus vannamei

Three six-week growth trials and a digestibility trial were conducted to evaluate a fish meal analogue (FMA) as a replacement for fish meal (FM) in shrimp feeds. Trials 1 and 2 evaluated and confirmed the potential of FMA supplementation (0, 48.5, 97, 145.5 and 194 g/kg) as a replacement for FM up to 200 g/kg without balancing for phosphorus (P) in practical diets for juvenile Pacific white shrimp L. vannamei. At the end of trial 1, shrimp offered diets containing 48.5 g/kg FMA exhibited significantly higher weight gain (WG) than those fed with the diet containing 145.5 g/kg FMA. At the end of trial 2, dietary FMA inclusion at 48.5 and 97 g/kg significantly improved WG and protein retention (PR), while reducing FCR and protein content of shrimp body compared to the diet containing 194 g/kg FMA. To determine whether P deficiency is the cause of reduced growth, the third trial was conducted utilizing equivalent diet but balanced for P. At the end of trial 3, shrimp fed diet containing 48.5 g/kg FMA+P showed significantly higher WG and PR than those fed diet containing 145.5 g/kg FMA+P. No decreasing trend of growth was detected in the diets containing FMA compared to the FM-based diet. Apparent digestibility coefficients of dry matter, energy, protein and amino acids of FMA were determined using chromic oxide as an inert maker and the 70:30 replacement technique. The energy, protein and individual amino acid digestibility of FMA were significantly lower than those of soybean meal and FM which were run at the same time. Results of this work indicate that FMA can replace up to 200 g/kg FM in shrimp diets with supplemental inorganic P. Given the good growth across the range of inclusion without any indication of a growth depression, the low nutrient digestibility of FMA may be due to an atypical response or the product simply does not work with the testing technique.