Standard Fish Meal Research Articles

Replacement of fish oil with a high-DHA algal oil in a fishmeal-free diet fed to Florida pompano (Trachinotus carolinus)

A 12-week growth trial was conducted to evaluate the complete co-replacement of fish meal (FM) and fish oil (FO) in juvenile Florida pompano (Trachinotus carolinus) diets. Five open-formula experimental diets were formulated as iso-nitrogenous (approximately 46% crude protein) and iso-lipidic (approximately 15% crude lipid). It is assumed that Florida pompano lack the mechanisms for synthesizing sufficient LC-PUFA. In the FM/FO-free diets, to meet the necessary dietary intake of LC-PUFA, a commercially available Schizochytrium algal oil was used. Four diets were prepared from a basal mix, with spirulina and poultry by-product meal as the principal protein sources. They differed only in their oil source, containing fish oil (FO), algal oil (AO), soy oil (SO), or a 50/50 blend of algal oil and soy oil (A/S). The fifth experimental diet (control) was a standard open-formula FM diet. In addition to the experimental diets, two commercial closed-formula diets served as references. The seven diets, each with four replicates, were stocked with 20 Florida pompano (approximately 4 g) in each. The experimental open-formula diets were tested against the control using Dunnett’s t-test, and different oil sources were tested against each other using orthogonal contrasts. The four experimental diets were each tested against the two reference diets with equivalency tests. Feed intake and survival were not different between the experimental diets and control. However, all production metrics were lower in the SO diet than the control. No other differences were observed between the FO, AO, and A/S diets and the control, or between the three diets. The feed conversion ratio (FCR) was higher in fish fed the SO diet than in fish fed the control diet, and no other differences were found. The protein efficiency ratio (PER) was higher in fish fed the control diet than in fish fed the experimental diets. Protein productive values (PPV) were similar to PER, except that the PPV in fish fed the AO diet was not different from the control. The contrasts revealed that the FO, AO, and A/S diets resulted in a lower FCR than the SO diet. The PER was higher in fish fed the AO diet, and lower in fish fed the SO diet. The PPV was higher in fish fed the AO diet than in fish fed the A/S and SO diets, but similar to that of fish fed the FO diet. There were striking differences in performance between the two commercial reference feeds, underscoring the importance of using well-defined open-formula diets as a reference or control. To our knowledge this is the first study to demonstrate that co-replacement of FM and FO can be achieved in Florida pompano by supplying an FM- and FO-free diet. The development of successful open-formula diets without FO will help spur innovation and sustainability in aquaculture production.

Cyberlindnera jadinii yeast as a functional protein source for Atlantic salmon (Salmo salar L.): Early response of intestinal mucosal compartments in the distal intestine.

The interplay between nutrition and the immune system is well recognized, and several studies show that experimental diets elicit local morphological changes and alteration of gene and protein expression in the intestinal mucosa of Atlantic salmon. In this study the pathophysiological effects of experimental diets on mucosal responses in the distal intestine of Atlantic salmon were investigated. Atlantic salmon were fed diets with inclusion of soybean meal (SBM) and Cyberlindnera jadinii (CJ) yeast for 7 days. A standard fish meal (FM) diet was used as a control. Morphological, immunohistochemical and gene expression analyses were used to evaluate the presence of immune cells, proliferating cells, and stem cell populations in mucosal compartments of the simple folds in the distal intestine. Fish fed SBM developed morphological changes consistent with SBM induced enteritis. Immunohistochemistry showed an increased presence of apoptotic cells, CD3ϵ and CD8α labelled cells in the simple fold epithelium of SBM group compared with the CJ group. For the investigated genes, expression levels in all three groups were mostly higher in the epithelial compartment of the simple fold than in the compartment beneath the folds. Most changes within the epithelial compartment were observed in fish fed SBM, where expression of CD3ζ, CD8α, MHC I and MHC II were lower than the FM control group. The CJ group had an increased expression of the stem cell marker Lgr5 in the epithelial compartment compared with SBM group. The division of the simple fold into an apical and basal compartment showed that the increase in Lgr5 was evident along the whole length of the simple folds and not confined to the base of the folds. Similarly, proliferation (PCNA, MCM2) and apoptosis (Caspase-3) gene expression was present in the entire length of the simple folds, suggesting that intestinal epithelial cell turnover is not confined to the basal or apical part of the fold. This study shows that the epithelial compartment is active in the early immunoregulatory response towards dietary stimuli and that the level of an intestinal stem cell marker in salmon was influenced by a diet containing CJ yeast.

Gökkuşağı alabalığı rasyonuna eklenen astaksantinin kas dokusu siyalik asit miktarı üzerine etkisinin araştırılması

Astaxanthin is an oxidized carotenoid component responsible for pigmentation, protecting essential polyunsaturated fatty acids from oxidation, immune response, communication, reproductive behavior, and improved reproduction in aquatic animals. In aquaculture, astaxanthin is a pigment used to give rainbow trout flesh its distinctive pinkish tint. Sialic acid is an alpha-keto acid monosaccharide with a nine-carbon backbone that is an acylated derivative of neuraminic acid and a terminal component of the oligosaccharide chains of many glycoproteins and glycolipids. It impacts cell recognition, communication, signaling, cellular aggregation and development, infections, tumor growth and metastasis, immunology, reproductive biology, and neurology. Forty female rainbow trout were used in the study. Fish were divided into two groups. The experimental group (n=20) received a daily dose of astaxanthin of 50 ppm/day for 225 days, whereas the control group (n=20) received a standard fish meal. The concentration of sialic acid in fish muscle tissue was evaluated using the enzyme-linked immunosorbent assay (ELISA) method. The sialic acid level in muscle tissue of fish fed a standard fish ration was 111.97 ± 4.56 µg/g, while the sialic acid level in muscle tissue of fish fed astaxanthin was 110.33 ± 8.54 µg/g. In our research, we found that adding astaxanthin to the fish diet had no effect on the amount of sialic acid in the fish, which is crucial in human nutrition. As a result, it was revealed that dietary astaxanthin did not influence the level of sialic acid in fish muscle tissue (p>0.05).

Effects of low fishmeal diets on growth performance, blood chemical composition, parasite resistance, and gene expression in the tiger pufferfish, Takifugu rubripes

The rising price of fishmeal and the need for sustainable use of fishery resources have encouraged efforts by the aquaculture industry to identify alternative protein sources including plants and single cell organisms. This is particularly the case for the tiger pufferfish, Takifugu rubripes, which is fed a high level of fishmeal as the protein source. In this study, we compared four possible replacement diets: in three diets, fishmeal was reduced from 77% to 47% and replaced mainly by plant (PP), bacterial (BAC), or yeast (LY)-derived ingredients; in the fourth, reduced to 20% and replaced mainly by yeast (HY). Growth performance, blood chemistry, transcriptomic responses in the liver, and resistance to the parasite Heterobothrium okamotoi were compared in 360 cultured tiger pufferfish (9.8 months old at the start of the experiment). After a 3-month feeding trial, the HY-fed fish showed increased standard lengths (p = 0.015) and body weights (p = 0.004) compared to control fish fed the standard FM (77% fishmeal) diet. At the end of the feeding trial, FM-fed fish had a mean hematocrit (Ht) of 29.3 ± 5.6%; HY-fed fish had the lowest mean Ht of 25.2 ± 5.1% (p = 0.005). Mean total cholesterol levels in BAC-, LY- and HY-fed fish were lower than in control fish (p = 0.008, 0.004, and 0.024, respectively). In contrast, no significant difference was found for triglyceride, total protein, and glucose levels among the groups. Subsequently, 150 individuals were subjected to artificial infection with H. okamotoi; no significant differences were found for mean parasite counts and Ht values between fish fed the experimental diets and the control fish. Analysis of gene expression in the liver showed that the gene hmgcra was significantly up-regulated (based on a log2 fold change threshold) in HY-fed fish compared to FM-fed fish. Overall, the analyses indicate that a low fishmeal diet in which 71% of fishmeal is replaced mainly by yeast meal (i.e., containing 40% of yeast meal in total mass) may be a suitable replacement for the commercial FM diet as it promotes growth but does not induce severe deleterious effects.

Effects of calcium carbonate inclusion in low fishmeal diets on growth, gastrointestinal pH, digestive enzyme activity and gut bacterial community of European sea bass (Dicentrarchus labrax L.) juveniles

Fishmeal (FM) possesses one of the highest buffering capacities in comparison to most alternative vegetable aquafeed ingredients and its decreasing content in current formulations might affect the ideal gastrointestinal environment for digestive enzyme action and gut bacterial community of carnivorous fish species. A study was undertaken, therefore, to assess growth response, gastrointestinal pH, digestive enzyme activity and gut bacterial community of European sea bass (Dicentrarchus labrax L.) juveniles fed low FM diets (10% FM) with or without a feed buffering additive, calcium carbonate (FM10 + B and FM10, respectively) in comparison to a standard FM diet (20% FM, FM20). Three isonitrogenous and isolipidic extruded diets were fed to triplicate fish groups of 80 individuals (initial weight: 23 g) to overfeeding over 64 days. No significant differences due to low FM dietary levels were observed in final body weight, specific growth rate, feed intake, feed and protein efficiency. Low FM diet did not affect gastrointestinal pH in the stomach, anterior intestine, mid-intestine and hindgut at 0, 4, 8 and 12 hours post meal (hpm) while the inclusion of calcium carbonate in low FM diet seems to slightly increase the pH in the hindgut at 12 hpm. The absence of significant differences of pepsin, chymotrypsin, amylase and lipase activity suggests a comparable digestive efficiency among treatments although trypsin activity was slightly reduced in low FM diets after 4 hpm. Decreasing FM content seems to exert an effect on the overall gut bacterial community analysed by next-generation sequencing even if no significant effects on specific bacterial component were detected. The gut bacterial community in all the treatments was particularly rich in lactic acid bacteria such as Lactobacillus spp. which may provide important beneficial functions for the host and be associated with a healthy intestinal epithelium. According to the results, increasing the feed buffering capacity does not seem to improve digestive conditions while it is feasible to include 10% FM dietary level in practical formulation for European sea bass juveniles without negatively affecting growth, feed efficiency and digestive luminal conditions.

Partial replacement of commercial fish meal with Amazon sailfin catfish Pterygoplichthys pardalis meal in diets for juvenile Mekong giant catfish Pangasianodon gigas

Aquatic resources in Thailand have been affected by the introduction of Amazon sailfin catfish, Pterygoplichthys pardalis. This species has had a negative impact on native fish and has not been caught and consumed widely. At present there is debate as to whether it will be best to remove them from natural water sources or find some way to gain benefits from the presence of this species in Thailand. This research was conducted to evaluate the possibility of replacing standard fish meal with P. pardalis meal in the diets of juvenile Mekong giant catfish, Pangasianodon gigas. Five diets with replacement levels of 0% (control), 25%, 50%, 75% and 100% were tested for 90 days. The results showed that the weight gain (WG), average daily growth rate (ADG), specific growth rate (SGR), feed conversion rate (FCR), feed efficiency (FE) and protein efficiency ratio (PER) were not significantly different when compared with the control group. In none of the groups mortality occurred. Moreover, serum biochemistry indices such as levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose, albumin, globulin, protein, triglyceride and cholesterol were not significantly different from the control group (ANOVA, p > 0.05). Based on our results, we conclude that commercial fish meal can be replaced with P. pardalis meal to make up 100% of the diet of P. gigas without producing any adverse effects on growth performance, feed utilization and serum biochemical indices.

Functional Genomic Analysis of the Impact of Camelina (Camelina sativa) Meal on Atlantic Salmon (Salmo salar) Distal Intestine Gene Expression and Physiology.

The inclusion of plant meals in diets of farmed Atlantic salmon can elicit inflammatory responses in the distal intestine (DI). For the present work, fish were fed a standard fish meal (FM) diet or a diet with partial replacement of FM with solvent-extracted camelina meal (CM) (8, 16, or 24 % CM inclusion) during a 16-week feeding trial. A significant decrease in growth performance was seen in fish fed all CM inclusion diets (Hixson et al. in Aquacult Nutr 22:615–630, 2016). A 4x44K oligonucleotide microarray experiment was carried out and significance analysis of microarrays (SAM) and rank products (RP) methods were used to identify differentially expressed genes between the DIs of fish fed the 24 % CM diet and those fed the FM diet. Twelve features representing six known transcripts and two unknowns were identified as CM responsive by both SAM and RP. The six known transcripts (including thioredoxin and ependymin), in addition to tgfb, mmp13, and GILT, were studied using qPCR with RNA templates from all four experimental diet groups. All six microarray-identified genes were confirmed to be CM responsive, as was tgfb and mmp13. Histopathological analyses identified signs of inflammation in the DI of salmon fed CM-containing diets, including lamina propria and sub-epithelial mucosa thickening, infiltration of eosinophilic granule cells, increased goblet cells and decreased enterocyte vacuolization. All of these were significantly altered in 24 % CM compared to all other diets, with the latter two also altered in 16 % CM compared with 8 % CM and control diet groups. Significant correlation was seen between histological parameters as well as between five of the qPCR analyzed genes and histological parameters. These molecular biomarkers of inflammation arising from long-term dietary CM exposure will be useful in the development of CM-containing diets that do not have deleterious effects on salmon growth or physiology.Electronic supplementary materialThe online version of this article (doi:10.1007/s10126-016-9704-x) contains supplementary material, which is available to authorized users.

Impact of Solar UV-B Radiation in the Culture of Pacific White Shrimp, Litopenaeus vannamei, Saudi Arabia

Middle East and North African (MENA) region are known for high levels of solar UV radiation. A study was conducted to assess the effect of UV radiation on phytoplankton chlorophyll, β-carotene and growth of pacific white shrimp, Litopenaeus vannamei in HDPE liner culture ponds for 98 days. The experiment is based on control ponds (direct sunlight) and treatment ponds (Green house) using intensive shrimp culture method. Shrimp juveniles (SPF) at the rate of 100/m2 were stocked in each pond and fed with a standard fishmeal based supplementary pellet feed having 35% protein in diet. Physico-chemical parameters of pond water, UV-B radiation, Chlorophyll-a, shrimp growth and β-carotene in meat were monitored during the study period. Significant reduction (p<0.01) in UV-B radiation was found in treatment ponds in comparison with control ponds at an average reduction of 23.2% for surface water due to filtration. Chlorophyll-a in phytoplankton and β- carotene in shrimp were found to be increased in treatment ponds due to low UV-B radiation. However, shrimp growth was not affected significantly (P>0.01) by UV-B radiation in culture ponds.

Comparison of intestinal gene expression in Atlantic cod ( Gadus morhua) fed standard fish meal or soybean meal by means of suppression subtractive hybridization and real-time PCR

Gene expression was studied in Atlantic cod fed two different diets, fish meal (FM) and dehulled and extracted soybean meal (SBM). RNA was isolated from the distal part of the mid-intestine of Atlantic cod and suppression subtractive hybridization (SSH) was employed to screen for genes that showed changes in expression in response to the two dietary treatments. We made a cDNA subtracted library, isolated and sequenced 192 clones. Identification of 157 clones was predicted by BLAST. Most of the clones were previously unidentified in cod. Expression of 12 selected clones was further studied by quantitative PCR. Expression of four clones showing similarity to aminopeptidase N, transcobalamin I precursor, cytochrome P450 3A40, and ras-related nuclear protein was significantly up regulated in intestine of cod fed SBM compared to cod fed FM. A trend towards up regulation of a clone with similarity to fatty acid binding protein in SBM-fed cod was also observed. No significant differences in expression were observed for: transmembrane 4 superfamily protein member, polypeptide N-acetylgalactosaminyltransferase, glutathione peroxidase, peroxiredoxin 4, SEC61, F-BOX, and 14-3-3.

An examination of the intestinal tract of Atlantic salmon, Salmo salar L., parr fed different varieties of soy and maize

This study was conducted to investigate the long-term effects of feeding plant products from both traditional breeding and from biotechnology on intestinal somatic indices, histology and cell proliferation in first-feeding Atlantic salmon, Salmo salar L. (initial weight 0.21 +/- 0.02 g). A standard fishmeal diet (standard fishmeal) was formulated to contain fishmeal as the sole protein source and suprex maize as the main starch source. Six experimental diets were then developed: two in which some of the fishmeal was replaced with commercially available, genetically modified Roundup Ready full-fat soybean meal (GM-soy) or commercially available, non-GM full-fat soybean meal (nGM-soy) at a level of 12.5% of the total diet, and four diets in which the suprex maize was replaced with two lines of GM-maize (Dekalb 1; D1 and Pioneer 1; P1), both products of event MON810, and their half-sibling non-GM counterparts (Dekalb 2; D2 and Pioneer 2; P2), at a level of 12.1% of total diet. Each diet was fed to fish in triplicate tanks and the experiment lasted for 8 months, during which the fish reached a final weight of 101-116 g. There was no significant effect of diet on the intestinal indices, nor were histological changes observed in the pyloric caeca or mid intestine. In the distal intestine, one of nine sampled fish fed nGM-soy showed moderate changes, two of nine sampled fish fed GM-soy showed changes, one with moderate and one with severe changes, and two of nine fish fed nGM-maize D2 had moderate changes. Using a monoclonal antibody against proliferating cell nuclear antigen (PCNA), cell proliferative responses to the experimental diets were assessed. In fish fed both soy diets, a significantly higher (P < 0.05) cell proliferation response was observed in the distal intestine concomitant with an increased localization of PCNA positive cells along the whole distal intestinal folds. The PCNA response among the nGM-soy group was significantly higher compared with all the other diet groups. In contrast, for fish exposed to dietary maize (type D) compared with fish fed the standard fishmeal, the soy-diets (GM-soy and nGM-soy) and maize (type P), a significantly lower (P < 0.05) cell proliferation response was observed in the distal intestine. Results indicated that the GM plant products investigated in this study, at about 12% inclusion level, were as safe as commercially available non-GM products, at least in terms of their effect on indices and histological parameters of the Atlantic salmon intestinal tract.

The utilization of diets containing high levels of fish protein hydrolysate by turbot ( Scophthalmus maximus) juveniles

A feeding trial was carried out to compare growth and feed utilization of turbot juveniles (mean initial weight of 58.5 g) fed diets including standard fish meal (diet A) or LT fish meal (diet B) from Denmark as the only protein sources, or standard fish meal and 5, 15 or 25% of a fish protein hydrolysate (diets C, D and E, respectively) as the protein source. The diets were formulated to contain 56% protein and 14% lipid and were prepared as dry pellets. At the end of the trial final weight of turbot fed diet B (173 g) tended to be higher than that of fish fed the other diets (126–155 g) but this difference was not statistically significant. Feed conversion ratio ranged between 0.9 and 1.2 and was not significantly different among groups. Furthermore, N retention (% N intake) was not significantly different among groups. Energy retention (EI) was significantly higher in fish fed diet B than in those fed diet C. Regarding whole body composition, at the end of the trial there were no significant differences in proximate composition among groups. Energy content was, however, significantly higher in fish fed diet B than in those fed diet C. ADC of the diets were determined in a separate trial, using settling columns for feces collection. The ADC of dry matter and energy were not significantly different among groups. The ADC of protein of diet B (77.8%) was higher than in the other groups but it was only significantly higher than that of diet C (74.2). It is concluded that turbot juveniles performed better with a diet including LT fish meal than standard fish meal as the only protein source. Partial replacement of fish meal with fish protein hydrolysate did not improve growth or feed utilization.

Plasma Biochemistry and Disease Resistance in Yellowtail Fed a Non-Fish Meal Diet.

Yellowtail Seriola quinqueradiata fed a non-fish meal diet and control fish fed a standard fish meal diet were reared in neighboring net-cages under the same natural environmental conditions. The growth and food consumption of the fish fed the non-fish meal diet (NFM fish) were similar to the fish fed the control diet (control fish). Mortality due to a natural infection with Pasteurella piscicida occurred among NFM fish, but not among control fish during 55 days of feeding experiment. Plasma total cholesterol, free cholesterol and phospholipid of NFM fish were significantly lower than those of control fish. This result indicates that the decrease in the levels of plasma lipid components may be a good indicator of reduced disease resistance in yellowtail.

Multi-element analysis of trace metals in some environmental samples by solvent extraction and high-performance liquid chromatography of metal chelate complexes

The use of high-performance liquid chromatography (HPLC), after preliminary solvent extraction, for the complete separation of trace amounts of metal chelates prior to their non-selective determination was investigated. A UV detector set to the most intense absorbance peak of the reagent was used as a universal detector for all of the metal chelates at approximately the same sensitivity. Sulphur-containing reagents such as dithizone and diethyldithiocarbamate were used owing to their high absorptivities and because they tend to form strong complexes with toxic metalloids. The absorption mode of HPLC was used, because metal chelates are typically very soluble in non-polar solvents such as chloroform. The high distribution ratios of the complexes in such solvents made possible the use of small volumes for extraction and hence obviated the need for evaporation prior to direct HPLC injection. The method was used for the analysis of trade effluents and compared with atomic-absorption spectrometry, and using a rapid wet-ashing procedure with nitric acid—hydrogen peroxide has been applied to standard kale and standard fish meal for calibration and to aquatic biota.