Sustitución de aceites de pescado en dietas de engorde de dorada (Sparus aurata) ricas en proteínas vegetales. Efectos sobre el crecimiento y los perfiles de ácidos grasos

216 páginas.-- Memoria presentada por Laura Benedito Palos para optar al grado de Doctor.[EN]: Aquaculture is one of the major consumers of fish meal and fish oil. However, the continuous expansion of aquaculture and the decreasing global availability of marine oil and fish meal force the industry to explore alternative and sustainable alimentary sources for fish feeds. To address this issue, the feasibility of combined replacement of fish meal and oil by vegetable ingredients was investigated in gilthead sea bream (Sparus aurata) and dietary effect on growth performance and tissue fatty acid profiles were examined. Four diets with a low level of fish meal inclusion were supplemented with lysine (0.55%) and contained soy lecithin (1%). Added oil was either fish oil (FO diet) or a blend of a vegetable oil mixture (17:58:25 of rapeseed:linseed:palm oils) replacing fish oil at 33, 66 and 100% (33VO, 66VO and VO diets).[ES]: El sector acuícola es una de las actividades industriales con más demanda de harinas y aceites de pescado. Sin embargo, debido al estancamiento de las pesquerías a nivel mundial, la actividad piscícola no puede estar basada únicamente en las reservas finitas de pescado. Por tanto, la sustitución de harinas y aceites de pescado por fuentes alternativas de materias primas resulta ineludible. Para abordar esta problemática, se analizó el efecto de dietas basadas en una sustitución conjunta de proteínas y aceites de pescado por ingredientes vegetales sobre el crecimiento y el perfil de ácidos grasos de doradas (Sparus aurata). El diseño de las dietas se realizó sustituyendo el aceite de pescado por una mezcla de aceites vegetales (17:58:25 de colza:linaza:palma) en un 0% (FO), 33% (33VO), 66% (66VO), 100% (VO). Todas las dietas se formularon con alta proporción de proteínas vegetales y se suplementaron con 1% de lecitina de soja y 0,55% de L-lisina.[VA]: El sector aqüícola és una de les activitats industrials amb més demanda de farines i olis de peix. No obstant això, a causa de l’estancament de les pesqueries a nivell mundial, l’activitat piscícola no pot estar basada únicament en les reserves finites de peix. Per tant, la substitució de farines i olis de peix per fonts alternatives de matèries primeres resulta ineludible. Per abordar esta problemàtica, es va analitzar l’efecte de dietes basades en una substitució conjunta de proteïnes i olis de peix per ingredients vegetals sobre el creixement i el perfil d’àcids grassos de daurades (Sparus aurata). El disseny de les dietes es va realitzar substituint l’oli de peix per una mescla d’olis vegetals (17:58:25 de colza:llinós:palma) en un 0% (FO), 33% (33VO), 66% (66VO), 100% (VO). Totes les dietes es van formular amb alta proporció de proteïnes vegetals i es van suplementar amb 1% de lecitina de soja i 0,55% d‘Llisina.Peer reviewe

Wide-targeted gene expression infers tissue-specific molecular signatures of lipid metabolism in fed and fasted fish

European sea bass (Dicentrarchus labrax) is one of the most important species for Mediterranean aquaculture. It is therefore crucial to establish appropriate feeding management regimens and to gain better knowledge of nutritional requirements for this species, exploring not only new feed ingredients and feeding strategies, but also understanding the molecular mechanisms that regulate the metabolism of nutrients. Accordingly, transcriptomic analysis represents a useful nutrigenomic discovery tool for identifying the molecular basis of biological responses to nutrition as well as nutritional biomarkers in fish. This study evaluated how the transcriptional activity of genes controlling lipid metabolism in European sea bass were modulated in a tissue-specific manner in response to fasting and refeeding. Such approach focused on a panel of 29 genes in which desaturases, elongases, triacylglycerol lipases, fatty acid-binding proteins, β-oxidation and oxidative phosphorylation enzymes, phospholipid-related enzymes, and transcription factors that regulate lipid homeostasis were represented. Fasting activated the lipolytic machinery in adipose tissue, liver and muscle of European sea bass, whereas markers of lipogenesis were downregulated in liver and adipose tissue. Genes involved in phospholipid and oxidative metabolism were differentially regulated in liver and skeletal muscle of fasted European sea bass. However, 12 days of refeeding were sufficient, for the most part, to reverse the expression of key genes. Overall, our data clearly showed a tissue-specific regulation of lipid-related genes according to the different metabolic capabilities of each tissue, being the brain the most refractory organ to changes in nutrient and energy availability and liver the most responsive tissue.This research was partly funded by AQUAEXCEL EU 7 FP Project (Grant Agreement 262336): Trans National Access Grant to S.R. for accessing to IATS-CSIC facilities. This work has been partly funded under the EU seventh Framework Program by the ARRAINA Project N288925: Advanced Research Initiatives for Nutrition & Aquaculture.Peer Reviewe

Wide-gene expression analysis of lipid-relevant genes in nutritionally challenged gilthead sea bream (Sparus aurata)

Disturbances of lipid metabolism are a major problem in livestock fish and the present study analysed the different tissue expression patterns and regulations of 40 lipid-relevant genes in gilthead sea bream. Nineteen sequences, including fatty acid elongases (4), phospholipases (7), acylglycerol lipases (8) and lipase-maturating enzymes (1), were new for gilthead sea bream (GenBank, JX975700-JX975718). Up to six different lipase-related enzymes were highly expressed in adipose tissue and liver, which also showed a high expression level of δ6 and δ9 desaturases. In the brain, the greatest gene expression level was achieved by the very long chain fatty acid elongation 1, along with relatively high levels of δ9 desaturases and the phospholipase retinoic acid receptor responder. These two enzymes were also expressed at a high level in white skeletal muscle, which also shared a high expression of lipid oxidative enzymes. An overall down-regulation trend was observed in liver and adipose tissue in response to fasting following the depletion of lipid stores. The white skeletal muscle of fasted fish showed a strong down-regulation of δ9 desaturases in conjunction with a consistent up-regulation of the >lipolytic machinery> including key enzymes of tissue fatty acid uptake and mitochondrial fatty acid transport and oxidation. In contrast, the gene expression profile of the brain remained almost unaltered in fasted fish, which highlights the different tissue plasticity of lipid-related genes. Taken together, these findings provide new fish genomic resources and contribute to define the most informative set of lipid-relevant genes for a given tissue and physiological condition in gilthead sea bream. © 2014 Elsevier B.V.This research was funded by the Spanish MICINN through AQUAFAT (AGL2009-07797; predictive modelling of flesh fatty acid composition in cultured fish species with different muscle lipid contents) and AQUAGENOMICS (CSD2007-00002, improvement of aquaculture production by the use of biotechnological tools) projects. Additional funding was obtained from EU project ARRAINA (KBBE-2011-5-288925, advanced research initiatives for nutrition and aquaculture).Peer Reviewe

Modelling the predictable effects of dietary lipid sources on the fillet fatty acid composition of one-year-old gilthead sea bream (Sparus aurata L.)

The present study aimed to ascertain the different fatty acid (FA) descriptors linking dietary and muscle FA composition in one-year-old gilthead sea bream. For that purpose, our own published data along with additional data from the present study were compiled and analysed. High linear correlations (r2 = 0.90, P < 0.001) between dietary and muscle fatty acid composition were reported for monoenes, C18 polyunsaturated FA (PUFA) and long-chain PUFA. Prediction deviations due to changes in muscle fatness were analyzed in an independent trial with two different feeding levels (full ration size, 30% restriction ration). Regardless of feeding regimen, predicted values for muscle FA at low concentrations deviated (P < 0.001) from observed values, but good predictions with less than 6% deviations were found for abundant fatty acids (16:1n-7, 18:1n-9, 18:2n-6, 18:3n-3, 20:4n-6, 20:5n-3, 22:6n-3). All this highlights the predictable effects of dietary oils in the muscle FA composition of gilthead sea bream, although further research is needed to cover all the range of commercial fish size and for the up-scaling of laboratory results to different fish farming conditions

Therapeutic management of allergic rhinitis: a survey of otolaryngology and allergology specialists

Purpose: To describe the current management of allergic rhinitis (AR) in Spain's specialized care according to the next-generation ARIA guidelines. Methods: An ad hoc online survey was distributed to AR specialists to appraise their perceptions of pathology management, knowledge of next-generation ARIA guidelines (including four case clinics), and their views on the principal barriers and the actions to proper AR management. Results: one hundred nine specialists (38.5% allergists and 61.5% otolaryngologists) completed the study survey. Most respondents (87.2%) had read all or part of the Next-Generation ARIA Guidelines, and 81.6% stated that they considered the patient’s treatment choice preferences. However, only 20.2% of specialists answered according to the recommendations in at least three of the four case clinics. Most participants failed to fulfill the treatment duration according to the guidelines. They regarded the lack of multidisciplinary teams (21.7%) and the lack of patients’ AR treatment adherence (30.6%) as the most critical healthcare system- and patient-related barriers to the correct management of AR, respectively. Promoting patients’ education was considered the most crucial action to improve it. Conclusion: Despite specialists’ awareness, there is a gap between the evidence-based guidelines’ recommendations and their implementation in clinical practice

Up-scaling validation of a dummy regression approach for predictive modelling the fillet fatty acid composition of cultured European sea bass (Dicentrarchus labrax)

The aim of the study was to validate a dummy regression approach for predictive modelling the fillet fatty acid (FA) composition of cultured European sea bass with dietary FA composition and lipid fillet content as independent variables. The model used our own data on gilthead sea bream as reference subgroup dataset and data from turbot, sole and European sea bass as dummy variables. Most of the observed variance within and among species was explained by the regression model without statistical significant interactions on blocks between diet composition and fish species subgroups. For the validation of European sea bass FA descriptors, predictive values derived from data on fish reared at laboratory scale were plotted against those obtained in farmed fish harvested at commercial size. A close linear association near to equality was found for 12 representative FAs, including saturated FAs, monoenenes and polyunsaturated FAs. This finding reinforces the possibility to produce tailored and healthy seafood products according to the guidelines of essential FA requirements in humans. FA algorithms for all the species in the model are hosted at www.nutrigroup-iats.org/aquafat as a multispecies tool to interrogate the nutritionally regulated FA composition of four cultured marine fish species of a high added value.This study was founded by Spanish (AQUAFAT, AGL2009-07797, Predictive modelling of flesh fatty acid composition in cultured fish species with different muscle lipid content) and EU (ARRAINA, KBBE-2011-5-288925, Advanced research initiatives for nutrition and aquaculture) projects. Additional founding was obtained from the “Generalitat Valenciana” (research grant PROMETEO 2010/006). GFB-L was recipient of a Spanish PhD fellowship from the Diputación Provincial de Castellón.Peer Reviewe

Dummy regression analysis for modelling the nutritionally tailored fillet fatty acid composition of turbot and sole using gilthead sea bream as a reference subgroup category

Farmed turbot and sole were sampled at different stages of the production cycle for analysis of fillet lipid content and fatty acid (FA) composition. The entire data set along with our own published data on gilthead sea bream were fitted to dummy regression equations with turbot and sole as dummy variables, gilthead sea bream as a reference subgroup category, and diet FA composition and fillet lipid content as independent variables. The relative contribution of each independent variable to the total variance was found to vary within and among FAs and fish species, but strong correlation coefficients (0.76 0.99) were found for almost all of the FA equations, including saturated FAs, monoenes and long-chain polyunsaturated fatty acids (PUFA) of n-3 and n-6 series. Given the differences in lipogenic activities of the fish species, major interaction effects between fillet lipid content and dummy variables were found for monoenes and saturated FAs. The proposed equations (hosted at www.nutrigroup-iats.org/aquafat) were able to fit different proportions of EPA, DPA and DHA underlying the fish species differences in FA desaturation/elongation pathways. The robustness of the model was proven with extra data from the three fish species, allowing a close linear association near to equality for the scatter plot of observed and predicted values. © 2014 John Wiley & Sons Ltd.This study was funded by Spanish (AQUAFAT, AGL2009-07797, Predictive modelling of flesh fatty acid composition in cultured fish species with different muscle lipid content; AQUAGENOMICS, CSD2007-00002, Improvement of aquaculture production by the use of biotechnological tools) and EU (ARRAINA, KBBE-2011-5-288925, Advanced research initiatives for nutrition and aquaculture) projects. Additional funding was obtained from the ‘Generalitat Valenciana’ (research grant PROMETEO 2010/006). GFB-L was recipient of a Spanish PhD fellowship from the Diputación Provincial de Castellón.Peer Reviewe

Lasting effects of butyrate and low FM/FO diets on growth performance, blood haematology/biochemistry and molecular growth-related markers in gilthead sea bream (Sparus aurata)

Four isoproteic/isolipidic plant protein-based diets were formulated to assess the lasting effects of feed additives and low fish meal (FM) and fish oil (FO) diet formulations on gilthead sea bream growth performance. FM was included at 23% in the control diet (D1) and at 3% in the other three diets (D2, D3, D4). Added oil was either FO (D1) or a blend of vegetable oils replacing 58% (D2) and 84% (D3, D4 diets) of FO. A commercial sodium butyrate preparation (NOREL, 70-BP) was added to the D4 diet at 0.4%. Each diet was allocated to triplicate groups of juvenile fish fed to satiety over an 8-month feeding trial (May-December). All fish grew efficiently from 15. g of initial body weight to 296-320. g with an overall feed efficiency (FE) of 0.95-1.01, although fish fed D3 and D4 diets showed transient growth impairments over the course of the first four weeks of the trial. Data on biometric indexes, whole body composition, haematology and blood biochemistry revealed a strong effect of sampling time in fish sampled at mid-summer (August) and late autumn (December). In contrast, the diet effect was mostly reduced to a few blood parameters. Low inclusion levels of FM reduced plasma haemoglobin levels (D2, D3), but these effects were reversed by butyrate supplementation (D4). The same phenomena occurred for total cholesterol with the highest circulating concentration of choline and IGF-I in fish fed the D4 diet during their summer growth spurt. At the transcriptional level, gene expression profiling of liver and skeletal muscle with a PCR-array of 87 growth markers provided additional evidence for an overall well-growth condition in all of the experimental groups. Up to 73 genes were found at detectable levels in the liver tissue, but only 13 were differentially expressed. Likewise, 84 genes were actively transcribed in the skeletal muscle, but only nine were differentially expressed in at least one experimental group. Butyrate supplementation reversed the up-regulated expression of inflammatory cytokines (TNFα) and muscle markers of cellular morphogenesis and protein breakdown (CDH15, CAPN3, PSMA5, PSMB1, UBE2N) in the muscle of fish fed the extreme D3 diet. These results support the use of low FM/FO diets alone or supplemented with feed additives, which have the potential to improve or reverse metabolic steady-states. Statement of relevance: Butyrate effect on low fish meal/fish oil diets.This study was funded by the European Union (ARRAINA, FP7-KBBE-2011-5-288925, Advanced research initiatives for nutrition and aquaculture) projects. Additional funding was obtained from the Spanish MINECO (MI2-Fish, AGL2013-48560) and from Generalitat Valenciana (PROMETEO FASE II-2014/085).Peer Reviewe

Effects of dietary NEXT ENHANCE®150 on growth performance and expression of immune and intestinal integrity related genes in gilthead sea bream (Sparus aurata L.)

Gilthead sea bream juveniles were fed different doses (0, 50, 100, 200, 300ppm) of NEXT ENHANCE®150 (NE) for 9 weeks. Feed gain ratio (FGR) was improved by a 10% with all the doses, but feed intake decreased in a dose dependent manner. The optimum inclusion level to achieve maximum growth was set at 100ppm. The hepatosomatic index did not vary and only at the highest dose, viscerosomatic and splenosomatic indexes were significantly decreased. No significant changes were found in haematological parameters, plasma biochemistry, total antioxidant capacity and respiratory burst. In a second trial, NE was given at 100ppm alone (D1) or in combination with the prebiotic PREVIDA® (0.5%) (PRE) (D2) for 17 weeks. There were no differences in the growth rates, and FGR was equally improved for D1 and D2. No significant changes in haematology and plasma antioxidant capacity were detected. The histological examination of the liver and the intestine showed no outstanding differences in the liver, but the number of mucosal foldings appeared to be higher in D1 and D2 vs CTRL diet and the density of enterocytes and goblet cells also appeared higher, particularly in the anterior intestine. A 87-gene PCR-array was constructed based on our transcriptomic database (www.nutrigroup-iats.org/seabreamdb) and applied to samples of anterior (AI) and posterior (PI) intestine. It included 54 new gene sequences and other sequences as markers of cell differentiation and proliferation, intestinal architecture and permeability, enterocyte mass and epithelial damage, interleukins and cytokines, pattern recognition receptors (PRR), and mitochondrial function and biogenesis. More than half of the studied genes had significantly different expression between AI and PI segments. The functional significance of this differential tissue expression is discussed. The experimental diets induced significant changes in the expression of 26 genes. The intensity of these changes and the number of genes that were significantly regulated were higher at PI than at AI. At PI, both diets invoked a clear down-regulation of genes involved in cell differentiation and proliferation, some involved in cell to cell communication, cytokines and several PRR. By contrast, up-regulation was mostly found for genes related to enterocyte mass, cell epithelial damage and mitochondrial activity at AI. The changes were of the same order for D1 and D2, except for fatty acid-binding proteins 2 and 6 and the PRR fucolectin, which were higher in D2 and D1 fed fish, respectively. Thus, NE alone or in combination with PRE seems to induce an anti-inflammatory and anti-proliferative transcriptomic profile with probable improvement in the absorptive capacity of the intestine that would explain the improved FGR. © 2015 Elsevier Ltd.This work has been carried out with financial support from the Commission of the European Communities, specific RTD programme of Framework Programme 7, (FP7/2007-2013) under grant projects ARRAINA (KBBE-2011-288925) and AQUAEXCEL (262336) under TNA project 0019/02/04/14 to ANDROMEDA. It does not necessarily reflect the EU views and in no way anticipates the Commission's future policy in this area. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Additional funding has been received by Spanish MINECO project no. AGL2013-48560 and Generalitat Valenciana (PROMETEOII/2014/085 and ISIC/2012/003).Peer Reviewe