Diets For Pacific White Shrimp Research Articles

Green seaweed Ulva sp. as an alternative ingredient in plant-based practical diets for Pacific white shrimp, Litopenaeus vannamei

In our previous research, the supplementation of Ulva sp. seaweed meal in shrimp feeds as a replacement for fish meal (FM) resulted in growth depression. To understand the factors causing the growth reduction and explore the effects of the seaweed meal as a substitution for soybean meal (SBM), a series of growth trials were conducted in the present study. Shrimp (initial mean weight 0.24, 0.15, and 0.98 g in trials 1–3, respectively) were stocked at 10 shrimp per tank (n = 4) and offered diets for 5 to 6 weeks. In trial 1, FM level was fixed and SBM was replaced using incremental level of the second batch Ulva meal (UM2). Two additional diets were formulated to allow comparison of high inclusion levels of seaweed meal from three batches (UM1–3). Results confirmed reductions in performance as replacement of SBM by Ulva meal was increased. This data also demonstrated significant difference between batches of the Ulva meal with the UM2 producing the poorest results. To elucidate if digestible protein was limiting growth, in trial 2 feeds were formulated on an equal digestible protein basis. At the end of trial 2, shrimp fed with diets containing UM2 exhibited significantly reduced growth performance, survival, and lipid content of whole shrimp body as well as increased feed conversion ratio (FCR) compared to the reference diet. Although performance of shrimp was depressed in the treatments containing UM1 and UM3, this was less than that of trial 2, indicating that protein quality may be part of the problem. Given the level of protein replacement, other components of Ulva meal are likely to be causing poor performance. A third trial was performed to evaluate the potential of the fourth batch Ulva meal (UM4) containing relatively higher protein content than the first three batches. In this trial, the growth, survival, and lipid content of whole shrimp body also decreased as the level of UM4 was increased. To survey possible problems caused by high levels of minerals, the meals and select diets were analyzed for mineral content. Clearly there are shifts in mineral profiles; however, there is no obvious correlation to a mineral. Other possible reasons would include anti-nutrients present in the algae. If Ulva meals are to be used to their full potential, e.g., as a primary protein source, the anti-nutritional components will need to be identified, specific lines of plants with enhanced nutrient value need to be developed and of course processing technologies evaluated to produce a high quality commercial product.

Evaluation of green seaweed Ulva sp. as a replacement of fish meal in plant-based practical diets for Pacific white shrimp, Litopenaeus vannamei

A growth trial and a digestibility trial were conducted to evaluate seaweed Ulva sp. as a substitution for fish meal (FM) in commercial-type feed formulation for Pacific white shrimp, Litopenaeus vannamei. Towards this goal, the 6-week growth trial utilized increasing levels (0, 6.35, 12.7, 19.05, and 25.4%) of the first batch of Ulva meal (UM1) to replace up to 8% FM in a plant-based feed formulation. At the end of the growth trial, shrimp offered diets containing 12.7, 19.05, and 25.4% UM1 exhibited significantly reduced weight gain. Apparent net protein retention (ANPR) was significantly decreased, while feed conversion ratio (FCR) was significantly increased when shrimps were fed with diets containing 19.05 and 25.4% UM1. Crude lipid content of whole shrimp samples were significantly decreased when UM1 was supplemented in the diets. Apparent digestibility coefficients of dry matter, energy, protein, and amino acids of two batches of Ulva meal (UM1 and UM2) were determined using chromic oxide as an inert maker and the 70:30 replacement technique. Energy and protein digestibility of UM1 and UM2 were significantly lower than FM and soybean meal (SBM) which were run at the same time. As a result of relatively low protein availability, individual amino acids digestibility of UM1 and UM2 are also significantly lower than those of FM and SBM. Results of the present study indicate that UM1 can be included in the shrimp diet up to 6.35% to replace 2% fish meal without resulting in growth depression. The low nutrients availability and high mineral contents of Ulva meal may explain a portion of the observed reduction in shrimp growth.

Evaluation of a novel bacterial biomass as a substitution for soybean meal in plant‐based practical diets for Pacific white shrimp Litopenaeus vannamei

Three growth trials and a digestibility trial were designed to evaluate the efficacy of a novel bacterial biomass (BB) in commercial-type feed formulation for Pacific white shrimp, Litopenaeus vannamei. In trial 1, the basal diet was supplemented with 0, 60 and 120 g/kg BB to replace soybean meal (SBM). Significant improvement was observed in the survival when BB was incorporated in the diets. However, shrimp fed diets containing 120 g/kg BB exhibited significantly lower weight gain (WG) and higher feed conversion ratio (FCR). To confirm the results from trial 1 and explore the effects of BB supplementation at low levels, the basal diet was incorporated with 0, 10, 20, 40, 60 and 120 g/kg BB to replace SBM in trial 2. Significant reductions in WG, FCR, lipid content of whole body, protein retention efficiency and most amino acids retention efficiency were detected in shrimp fed with diet containing 120 g/kg BB. Trial 3 was designed to elucidate whether the digestible protein is the cause of reduced growth. No improvements in terms of growth performance and FCR were detected in the treatments balanced for digestible protein. Apparent digestibility coefficients of energy, protein and amino acid (AA) for BB were determined using chromic oxide as an inert marker and the 70:30 replacement technique. The energy, protein and individual amino acid digestibility coefficients of BB were significantly lower than those of fish meal (FM) and SBM that were given at the same time. Results of this study indicated that BB can be utilized up to 40 g/kg in shrimp feed without causing a decrease in growth. However, supplementations (≥60 g/kg) of BB can result in negative effects on growth response, FCR and protein as well as amino acids retention efficiency. At the lower levels of inclusion, shrimp performance was improved when BB was supplemented on a digestibility basis; however, at the higher level of inclusion, there was no improvement, indicating there may be other nutrients limiting. Based on enhanced survival in the treatment with BB supplementation in trial 1, further research regarding the immune effects of BB in practical shrimp feed will be necessary.

Partial and total replacement of fish meal by marine microalgaSpirulina platensisin the diet of Pacific white shrimpLitopenaeus vannamei: Growth, digestive enzyme activities, fatty acid composition and responses to ammonia and hypoxia stress

In the this study, we evaluated the effect of replacement of fish meal by a marine microalgae Spirulina platensis on growth, digestive enzyme activities, fatty acid composition and responses to ammonia and hypoxia stress in Pacific white shrimp Litopenaeus vannamei (2.6 ± 0.2 g). Experimental diets contained S. platensis at 0%, 25%, 50%, 75% and 100% replacement levels. After 8 weeks of feeding trial, growth parameters and proximate body composition were not significantly different among treatments (p > .05). Amylase and lipase activities did not show any significant differences between control group and other experimental diets (p > .05), while activities of trypsin and chymotrypsin were significantly higher in shrimp fed diet with 50% substitution of microalgae compared to control group. Fatty acid contents, particularly polyunsaturated fatty acids (PUFAs) including arachidonic acid (ARA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), were significantly higher in control diet compared to other experimental diets. On the contrary, the majority of fatty acids including the contents of PUFAs in the whole body of L. vannamei fed with different levels of S. platensis were significantly higher compared to those of control group. After 48-h exposure to ammonia, survival per cent was not statistically different between all groups (p > .05), but in hypoxia challenge, the survival per cent of control group was significantly less than that of treatments fed diets contained S. platensis (p < .05). Altogether, our results demonstrated the effectiveness of S. platensis as a reliable protein source for substitution of fish meal in shrimp aquaculture.

Evaluation of black soldier fly (Hermetia illucens) larvae meal as partial or total replacement of marine fish meal in practical diets for Pacific white shrimp (Litopenaeus vannamei)

Black soldier fly larvae (BSFL) meal, produced from the larvae of Hermetia illucens, has shown promise as a fish meal (FM) replacement in diets for rainbow trout, catfish and tilapia, but has not been examined as an alternative protein source in shrimp diets. Six isonitrogenous (35% crude protein, as fed) and isoenergetic (16.7kJ available energy g−1 of diet) diets containing graded levels of BSFL as replacements for protein from menhaden FM were fed to juvenile (1.24g±0.01; mean±SE) Pacific white shrimp, Litopenaeus vannamei. Diet 1 (the control) was formulated similar to a commercial shrimp diet containing 25% menhaden FM and 23% soybean meal. Diets 2–6 were formulated as a dose-response series that progressively replaced protein from menhaden FM with BSFL meal at inclusion rates of 7%, 14%, 21%, 28%, and 36% of diet; this equated to progressively replacing 16.5% of dietary protein provided by menhaden FM. Diets were fed to juvenile shrimp stocked into eighteen 110-L saltwater aquaria (30ppt) (three replicates per dietary treatment) at a density of 15 shrimp per aquarium (50/m2) for 63days. Nonlinear and spline regression analysis of responses indicated that the maximum level of BSFL meal inclusion varied significantly with the response being modeled. Generally, without modification of the ingredient or replacement diet nutrient profiles, 95% to 100% of most growth responses, i.e., shrimp final weight, weight gain, specific growth rate, and food conversion, could be obtained if replacement of FM by BSFL meal was limited to <25% of the diet, depending on performance measure. Similarly, 95% or greater of maximum whole-body protein and lipid content could be achieved when BSFL inclusion was restricted to <29% and 15%, respectively. Comparison of amino acid profiles in the test diets with recent requirement estimates for limiting amino acids in BSFL meal also suggest future strategies for increasing dietary substitution of FM with BSFL.

Evaluation of flash dried yeast as a nutritional supplement in plant-based practical diets for Pacific white shrimp Litopenaeus vannamei

Growth and digestibility trials were conducted to evaluate the use of flash dried yeast (FDY) as a supplement in practical shrimp feeds. The six-week growth trial evaluated the effects of FDY supplementation (0, 10, 20, 40 and 60 g kg–1) in the plant-based practical diet on the performances and proximate compositions of juvenile Pacific white shrimp, Litopenaeus vannamei. Final biomass, final mean weight, per cent weight gain (WG), feed conversion (FCR) and protein retention efficiency (PRE) of Pacific white shrimp were not significantly influenced when FDY was added up to 40 g kg–1 of the diet. However, 60 g kg–1 FDY supplementation significantly reduced growth, feed utilization and protein retention. Supplementation of FDY in the practical diets of Pacific white shrimp did not affect protein, moisture, lipid, crude fibre, and ash content of whole shrimp body. Apparent digestibility coefficients of energy, protein, and amino acid (AA) for FDY were determined using chromic oxide as an inert marker and the 70:30 replacement technique. The energy and protein digestibility of FDY were 38.20% and 53.47%, respectively, which were significantly lower than fishmeal (FM) and soybean meal (SBM) that were run at the same time. Most amino acid digestibility of FDY was lowest among the three ingredients tested. Results of this work indicated that energy, protein and amino acid digestibility of FDY are lower compared to SBM and FM, and high levels supplementation (≥60 g kg–1) of FDY can cause negative effects to the growth response of Pacific white shrimp. Based on these results, further research regarding the effects of the low level inclusion of FDY in practical diets on immune responses of Pacific white shrimp is warranted.

Evaluation of three non-genetically modified soybean cultivars as ingredients and a yeast-based additive as a supplement in practical diets for Pacific white shrimp Litopenaeus vannamei

Two growth trials and a physiology assessment were conducted to evaluate three non-genetically modified (GM) soybean cultivars as ingredients in practical diets for Pacific white shrimp, Litopenaeus vannamei. In addition, a commercially available fermented yeast product was evaluated as dietary supplement. For the growth trials (46 and 35 days, respectively, for trials 1 and 2), the basal diet was primarily composed of soybean meal (SBM), fishmeal (FM), whole wheat, corn protein concentrate, poultry meal (PM, pet food grade) and corn starch. Non-GM cultivars were processed with novel methodologies to produce Navita™ ingredients (N1, N2 and N3) which were incorporated at low (L) or high (H) levels into the experimental diets, in partial replacement of FM and full replacement of conventional SBM. The last two formulations incorporated the fermented yeast for a total of nine experimental diets (Table 1). Results from the growth trials indicate that shrimp fed diet 5 (HN2) exhibited significantly lower (p < .05) weight gain as compared to shrimp fed diets 1 and 2 (basal and LN1, respectively) in trial 1, as well as compared to animals fed diets 1, 2, 3 and 8 (basal, LN1, HN1 and basal + yeast) in trial 2. The feed conversion ratio significantly increased for shrimp fed diet 5, in contrast with shrimp fed diets 1, 2, 3 and 8 in trials 1 and 2, as well as compared to shrimp fed diets diet 6 (LN3) in trial 2. For the physiological assessment (stress and immune responses), only the effects of diets 1, 3, 8 and 9 (basal, HN1, basal + yeast and HN1 + yeast, respectively) were investigated. Granular cell counts were significantly higher for shrimp fed the yeast-containing diets. Haemolymph glucose and haemolymph packed cell volume were significantly reduced for shrimp fed diets 3, 8 and 9. No significant differences were observed in total haemocyte counts, hyaline cells counts, semi-granular cells counts, haemolymph protein, haemocyte phagocytic capacity and haemocyte respiratory burst activity. Results of this work indicate that selective soy breeding technology coupled with novel processing options has the potential to increase the nutritional value of conventional SBM for shrimp feeds. Trends on immune responses were more difficult to elucidate possibly due to the limited length of the feeding trial.

Green Water Meal as Protein and Carotenoid Sources in Grow-out Diets for Pacific White Shrimp, Litopenaeus vannamei

The present study was conducted to evaluate the potential of green water meal (GWM) as an alternative dietary ingredient for juvenile Pacific white shrimp, Litopenaeus vannamei. Five isoproteic and isolipidic diets were formulated with 0% (GWM0, control diet), 10% (GWM10), 20% (GWM20), 30% (GWM30) and 40% (GWM40) of GWM replacing fishmeal protein and fed five times daily to triplicate groups of shrimp with an average initial weight of 6.42±0.02 g. In general, growth performance and feed utilization of shrimp fed with GWM10 did not show any significant differences with the control diet. Survival rate was above 88% and not affected by the dietary treatments. The whole-body protein and lipid of the shrimps decreased with the increasing GWM level in the diets. The shrimps fed with the GWM-based diets (GWM10, GWM20, GWM30 and GWM40) presented more intense red/orange colour and contained higher total carotenoid concentration compare with the control diet. The present findings suggested that GWM is an excellent source of carotenoid for shrimp pigmentation and able to replace fishmeal protein at up to 10% replacement level.

Supplemental Effects of AAMC, an Anionic Alkali Mineral Complex, in Diets for Pacific White Shrimp (Litopenaeus vannamei)

A 6-week feeding trial was conducted to evaluate the effect of dietary supplementation of Anionic Alkali Mineral Complex (AAMC) on growth performance, feed utilization, innate immunity, and disease resistance of L. vannamei. Graded levels of AAMC solution were included in a basal diet; 0% (Control), 0.05%, 0.1%, 0.2% and 0.4%. Shrimp fed diets supplemented with 0.2% and 0.4% AAMC had the highest growth performance, and compared to the control treatment, final body weight and specific growth rates were significantly higher (P&lt;0.05). Feed utilization also improved significantly with AAMC supplementation. Non-specific immune responses of shrimp were significantly affected by dietary supplementation of AAMC; total hemocyte count of shrimp fed 0.1% and 0.2% diets was significantly higher the control diet shrimp group. Phenoloxidase and lysozyme activity was significantly higher in shrimp fed 0.2% diet compared to the control diet group. Glutathione peroxidase activity was significantly enhanced with dietary supplementation of 0.1%–0.2% AAMC. In a challenge test with Vibrio harveyi, shrimp fed 0.2% AAMC disease resistance was significantly higher than in shrimp fed the control diet. Overall, the results indicate that dietary supplement of AAMC improved growth, diet utilization, innate immunity, and disease resistance of Pacific white shrimp and approximately 0.2% in diets appeared to be the optimum supplemental level.

Supplemental Effects of AAMC, an Anionic Alkali Mineral Complex, in Diets for Pacific White Shrimp (Litopenaeus vannamei)

A 6-week feeding trial was conducted to evaluate the effect of dietary supplementation of Anionic Alkali Mineral Complex (AAMC) on growth performance, feed utilization, innate immunity, and disease resistance of L. vannamei. Graded levels of AAMC solution were included in a basal diet; 0% (Control), 0.05%, 0.1%, 0.2% and 0.4%. Shrimp fed diets supplemented with 0.2% and 0.4% AAMC had the highest growth performance, and compared to the control treatment, final body weight and specific growth rates were significantly higher (P&lt;0.05). Feed utilization also improved significantly with AAMC supplementation. Non-specific immune responses of shrimp were significantly affected by dietary supplementation of AAMC; total hemocyte count of shrimp fed 0.1% and 0.2% diets was significantly higher the control diet shrimp group. Phenoloxidase and lysozyme activity was significantly higher in shrimp fed 0.2% diet compared to the control diet group. Glutathione peroxidase activity was significantly enhanced with dietary supplementation of 0.1%–0.2% AAMC. In a challenge test with Vibrio harveyi, shrimp fed 0.2% AAMC disease resistance was significantly higher than in shrimp fed the control diet. Overall, the results indicate that dietary supplement of AAMC improved growth, diet utilization, innate immunity, and disease resistance of Pacific white shrimp and approximately 0.2% in diets appeared to be the optimum supplemental level.

Replacement of fish meal by protein soybean concentrate in practical diets for Pacific white shrimp

The objective of this work was to evaluate the performance of Litopenaeus vannameifed different levels (0, 25, 50, 75, and 100%) of soybean protein concentrate (63.07% crude protein, CP) to replace fish meal-by product (61.24% CP). The study was conducted in clear water in fifteen 800 L tanks equipped with aeration systems, constant heating (29 oC), and daily water exchange (30%). Each tank was stocked with 37.5 shrimp/m3 (3.03±0.14 g). Feed was supplied four times a day, at 6% of the initial biomass, adjusted daily. After 42 days, the weight gain of shrimp fed diets with 0 and 25% protein replacement was higher than that observed in shrimp fed 100% replacement, and there were no differences among those fed the other diets. Feed efficiency and survival did not differ among shrimp fed different protein replacements. There was a negative linear trend for growth parameters and feed intake as protein replacement with soybean protein concentrate increased. Fish meal by-product can be replaced by up to 75% of soybean protein concentrate, with no harm to the growth of Pacific white shrimp.

Use of Lipid‐Extracted Distillers Dried Grain with Solubles (DDGS) in Diets for Pacific White Shrimp

AbstractA series of trials (one growth trial and two digestibility trials) were conducted to evaluate the response of Pacific white shrimp Litopenaeus vannamei to the inclusion of lipid‐extracted distillers dried grain with solubles (LE‐DDGS). In the growth trial, a practical basal diet was developed for shrimp using soybean meal (56.76% diet) and fish meal (6% diet) as the primary protein sources. The LE‐DDGS was substituted for soybean meal on an isonitrogenous basis at five levels of inclusion (0, 10, 20, 30, and 40%) with lysine supplemented to diets containing 30% and 40% LE‐DDGS. A sixth diet containing 40% LE‐DDGS but without a lysine supplement was also evaluated. The diets were offered to four replicate (15 shrimp/tank) groups of shrimp per treatment over an 8‐week growth trial. At the end of the growth trial shrimp offered diets containing from 0% to 20% LE‐DDGS performed similarly. Performance of shrimp fed higher levels of LE‐DDGS was reduced but similar to each other. Removing the lysine supplement from the diet containing 40% LE‐DDGS did not result in reduced performance of the shrimp, indicating lysine was not limiting in these feeds. In two digestibility trials, the LE‐DDGS digestibility coefficients were determined in Pacific white shrimp for dry matter (ADMD), energy (AED), and crude protein (APD) using 1% chromic oxide as the inert marker with 70:30 replacement strategies. The ADMD, AED, and APD coefficient values for LE‐DDGS were 53.77, 36.94, and 55.71 for digestibility trial 1 and 42.43, 44.65, and 20.87 for digestibility trial 2, respectively. Results from the digestibility data do not match the results of the growth trial, as poor digestibility would have resulted in more pronounced reduction in performance. Hence, this digestibility technique may not be appropriate for this type of ingredient. Based on the observed results the inclusion of LE‐DDGS up to 20% of the diet is recommended.

Evaluation of jumbo squid (Dosidicus gigas) byproduct hydrolysates obtained by acid-enzymatic hydrolysis and by autohydrolysis in practical diets for Pacific white shrimp (Litopenaeus vannamei)

The marine bioprocessing industry offers great potential to utilize byproducts for fish meal replacement in aquafeeds. Jumbo squid is an important fishery commodity in Mexico, but only the mantle is marketed. Head, fins, guts and tentacles are discarded in spite of being protein-rich byproducts. This study evaluated the use of two jumbo squid byproduct hydrolysates obtained by acid-enzymatic hydrolysis (AEH) and by autohydrolysis (AH) as ingredients in practical diets for shrimp. The hydrolysates were included at levels of 2.5 and 5.0% of the diet dry weight in four practical diets, including a control diet without hydrolysate. Shrimp growth and survival were not significantly affected by the dietary treatments. Postharvest quality of abdominal muscle was evaluated in terms of proximate composition and sensory evaluation. Significantly higher crude protein was observed in the muscle of shrimp fed the highest hydrolysate levels, AH 5% (204.8 g kg - 1) or AEH 5% (201.3 g kg - 1). Sensory analysis of cooked muscle showed significant differences for all variables evaluated: color, odor, flavor, and firmness. It was concluded that Jumbo squid byproducts can be successfully processed by autohydrolysis or acid-enzymatic hydrolysis, and that up to 5.0% of the hydrolysates can be incorporated into shrimp diets without affecting growth or survival.

Replacement of Fish Meal with Soybean Meal, Alone or in Combination with Distiller's Dried Grains with Solubles in Practical Diets for Pacific White Shrimp, Litopenaeus vannamei, Grown in a Clear‐Water Culture System

AbstractThe objective of this study was to evaluate inclusion of distiller's dried grains with solubles (DDGS) as partial replacement of commercial, solvent‐extracted soybean meal (SBM) in fish meal‐free diets for Pacific white shrimp, Litopenaeus vannamei. Aquaria connected to a recirculating biofiltration system were utilized to evaluate growth, survival, and feed conversion of shrimp during the 8‐wk feeding trial. Each 110‐L aquarium was stocked with 15 shrimp (mean individual weight 0.99 g) and fed one of five diets: a diet containing 20% fish meal (FM), which served as the control (Diet 1); a diet containing 0% FM and 52.5% SBM (Diet 2); and diets containing 0% FM and either 10, 20, or 30% DDGS as partial replacement of SBM (Diets 3, 4, and 5, respectively). Shrimp were fed according to a pre‐determined feeding chart five times daily (0730, 1030, 1330, 1630, and 1930 h) and there were three replicates per dietary treatment. The results from the feeding trial demonstrated that final weight, weight gain (g), and percentage weight gain were significantly higher (P &lt; 0.05) for shrimp fed Diet 1 (10.96 g, 10.01 g, and 1051%, respectively) compared to shrimp fed diets containing DDGS; however, shrimp fed diets containing DDGS had similar (P &gt; 0.05) final weight, weight gain (g), and percentage weight gain as shrimp fed a diet containing 0% FM and 52.5% SBM (Diet 2). Feed conversion ratio (FCR) of shrimp fed Diet 1 (2.84) was significantly lower (P &lt; 0.05) compared to shrimp fed any other diet. Survival (%) was not different (P &gt; 0.05) among treatments and averaged 77.3% for the study. This study demonstrated that practical shrimp diets containing no FM had an adverse impact on growth performance of white shrimp when grown in a clear‐water system and that further research is needed to refine diet formulations when culturing shrimp in these systems when attempting to feed a diet without FM.

A review of the development and application of soybean-based diets for Pacific white shrimpLitopenaeus vannamei

The production of the Pacific white shrimp (Litopenaeus vannamei) has expanded to the point of being the most widely cultured species of shrimp. One of the advantages of this species is its acceptance of a wide variety of feed formulations including plant-based feeds. Given the increases in ingredient costs, particularly fish meal, there is considerable interest in the use of alternative feed formulations for cultured species. Given that soybean meal is one of the most widely available protein sources for which production can be expanded, the move to soy-based diets is inevitable. The successful use of alternative feed ingredients for shrimp production depends on a number of factors. This paper summarizes studies regarding the move towards high soy diets concerning manipulation of ingredients and nutrient profiles to maintain balanced feed formulations.

Optimal content and ratio of lysine to arginine in the diet of Pacific white shrimp, Litopenaeus vannamei

The optimal quantity of dietary lysine (Lys) and arginine (Arg), and the optimal ratio of dietary Lys to Arg for Pacific white shrimp Litopenaeus vannamei were investigated. Coated Lys and Arg were added to a basal diet (37.99% crude protein and 7.28% crude lipid) to provide graded levels of Lys and Arg. The experimental diets contained three Lys levels (2.51%, 2.11%, and 1.70% of total diet), and three Arg levels (1.41%, 1.80%, and 2.21% of total diet) and all combinations of these levels were tested. Pacific white shrimp, with a mean weight of 3.62±0.1 g, were randomly distributed in 36 fiberglass tanks with 30 shrimp per tank and reared on the experimental diets for 50 days. After the feeding trial, the growth performance, survival, feed conversion rate (FCR), body composition and protease and lipase activities in the hepatopancreases of the experimental shrimps were determined. The results show that weight gain (WG), specific growth rate (SGR), FCR, body protein, body Lys and Arg content were significantly affected by dietary Lys and Arg (P 0.05). Therefore, according to our results, the optimal Lys and Arg quantities in the diet of Pacific white shrimp, L. vannamei, were considered to be 2.11%–2.51% and 1.80%–2.21%, respectively, and the optimal ratio to be 1:0.88–1:1.05.

An evaluation of pink salmon (Oncorhynchus gorbuscha) testes meal in diets for pacific white shrimp(Litopenaeus vannamei): effect on palatability, digestibility and growth performance

This study compared the nutritional profiles of menhaden fishmeal and pink salmon (Oncorhynchus gorbuscha) testes meal and investigated the nutritional values of the testes meal based on its effect on palatability, digestibility and growth performance of Pacific white shrimp (Litopenaeus vannamei). The testes meal replaced 0–91% of fishmeal protein in a control diet containing 150 g kg−1 fishmeal. Replacement of 69% of the fishmeal protein in the control diet significantly increased feed intake of shrimp from 0.61% to 1.10%. The apparent digestibility coefficient of dietary protein increased significantly when 91% of the fishmeal protein was replaced by the testes meal. Replacement of dietary fishmeal protein with up to 46% testes meal protein did not cause adverse effects on growth rate or nutritional composition of tail muscle. However, growth rate was significantly decreased in shrimp fed diets in which 69% or 91% of fishmeal protein was replaced by the testes meal. Results of this study indicate that the testes meal can be used as a feed additive to enhance the palatability and protein digestibility of low fishmeal diets for shrimp. It can replace up to 46% of fishmeal protein without any adverse effect on the growth performance of shrimp.

Effects of different levels of energy and protein sources on the growth performance, feeding, survival rate and the chemical body composition of juvenile pacific white shrimp (Litopenaeus vannamei)

The present study was carried out in order to establish an economical effective diet for the pacific white shrimp in the southern part conditions of Iran. With the consideration of three dietary energy levels (E1=262, E2=312, E3=362 kcal 100 g-1 diet) and six ratios of fish meal (FM) to soybean meal (SBM) [(P1=100%FM+0%SBM, P2=80%FM+20%SBM, P3=60%FM+40%SBM, P4=40%FM+60%SBM, P5=20%FM+80%SBM, P6=0%FM+100%SBM)], 18 experimental diets (with 36% crude protein) were prepared. Completely randomized design was used to assign 54 polyethylene 300 litre round tanks provided by aeration and flow through water system and was stocked by 19 juvenile as 3 replicates to each treatment. Shrimps average weight was about 0.77 grams at the start. After 56 days culture period, maximum growth and nutritional performances were observed in the P6E1 treatment (containing 100% soybean meal and 262 kcal 100 g-1 diet) and P5E1 treatment (containing 80% soybean meal and 262 kcal 100 g-1 diet). Also the highest survival rate of the shrimps was observed in the P1E1, P1E2, P3E3 and P5E3 treatments. Additionally interactive effect of different protein ratios and energy levels had significant difference on body protein, fat, fiber and ash contents (P<0.05). Results of the present study suggest the possibility replacement of at least 80% of dietary fish meal by soybean meal in the diet of pacific white shrimp in the conditions of southern part of Iran.

Effects of Dietary Nucleotides on the Immune Response and Growth of Juvenile Pacific White Shrimp Litopenaeus vannamei (Boone, 1931)

Effects of dietary supplementation of nucleotides on immune response, survival against white spot syndrome virus (WSSV) challenge infection and growth of Pacific white shrimp Litopenaeus vannamei (Boone, 1931) juveniles were evaluated. The basal diet for Pacific white shrimp supplemented with nucleotide formula (Vannagen; Chemoforma, Augst, Switzerland) at 0%, 0.2%, 0.4% and 0.6% kg of feed were tested. Survival of shrimp was in the range of 92-97% and was not significantly different among treatments. However, specific growth rate (SGR), feed conversion efficiency (FCE) and protein productive value (PPV) were significantly better in shrimps fed the nucleotide-supplemented diet than those fed the control diet after a 60-day feeding trial. Survival of test animals upon challenge with WSSV infection was significantly higher in the nucleotide group than in the control group. Immune response indices i.e. total haemocyte count (THC), respiratory burst activity and phenoloxidase activity were significantly enhanced in shrimp fed diets containing nucleotides as compared to those fed diets with no supplementation. At the levels tested, 0.2% nucleotide in the diet was the optimum. These results indicate that dietary supplementation of nucleotides resulted in beneficial effects in improving growth, feed utilisation, protein utilisation and accelerate shrimp immune response against WSSV infection.

A defatted microalgae (Haematococcus pluvialis) meal as a protein ingredient to partially replace fishmeal in diets of Pacific white shrimp (Litopenaeus vannamei, Boone, 1931)

This trial evaluated the effects of partial replacement of fishmeal protein by a defatted microalgae meal (DMM) in a shrimp diet. The DMM was a by-product of astaxanthin production from Haematococcus pluvialis and contained 40.3% crude protein (CP) and 0.9% crude lipid (CL). Test diets were prepared by using DMM (3, 6, 9 and 12% in a diet) to replace 12.5%, 25%, 37.5% or 50% of a fishmeal protein in a control diet (32.3% CP & 8.9% CL). All test diets had similar protein and lipid levels. Each diet was randomly assigned to four tanks (12 juvenile shrimp per tank) in an indoor flow through seawater laboratory. After an 8-week feeding trial, shrimp fed the diet with 12.5% of the fishmeal protein replaced showed a significantly higher growth rate and lower feed conversion ratio than the shrimp fed the control diet (P<0.05). The other three DMM-added diets had a similar effect on the growth of shrimp as the control diet (P>0.05). Shrimp fed the four DMM-added diets appeared redder and contained higher free and esterified astaxanthins than shrimp fed the control diet. The results indicated that DMM could be a valuable alternative protein and pigmentation ingredient in shrimp feed.