870 research outputs found

    Biometry traits and geometric morphometrics in sea bass (Dicentrarchus labrax) from different farming systems

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    The effect of the farming system on biometry traits and dressing out yield were inves- tigated in market-size European sea bass (Dicentrarchus labrax) cultured extensively or intensively in sea cages or land-based basins. Fish external appearences and shapes were studies with geometric morphometrics in order to assess the potential of combined methodologies in the assessment of finfish quality. Both standard biometry and geometric morphometrics were able to discriminate between sea bass farmed extensively from those cultured under intensive conditions. Geometric morphometrics has been shown to be a valuable tool for describing changes in shape features and could result a useful technique to be associated to biometry traits in the context of fish quality assessment

    growth and nitrogen metabolism of sea bass fed graded levels of nucleic acid nitrogen from yeast or rna extract as partial substitute for protein nitrogen from fish meal

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    Some studies carried out in mammalian models have shown de novo synthesis and salvage of nucleotides to be a costly metabolic process and a dietary supplementation with nucleic acids (NA) or nucleotides has been suggested to result in a protein sparing action (Sanderson and He, 1994). On the other hand, high levels of dietary NA could have toxic effects and lead to disturbance in protein, lipid and carbohydrate metabolism in monogastric animals lacking uricase activity, an enzyme involved in NA degradation (Clifford and Story, 1976). So far, there is no clear indication of such effects in fish fed nucleic acid-enriched diets (Tacon and Cooke, 1980; Rumsey et al., 1992; Fournier et al., 2002). The aim of this experiment was to investigate growth response and N metabolism in juvenile sea bass (D. labrax) fed diets supplying graded levels of nucleic acid N from dry brewer's yeast or RNA extract as partial substitutes for protein nitrogen provided by fish meal

    Growth performance of sea bass fed increasing levels of pea-wheat protein in diets varying in fish meal quality

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    A 11-week trial was carried out to compare the growth performance of sea bass (D. labrax) fed six isonitrogenous isocaloric diets where protein from two fish meals of different nutritive value was replaced with graded levels (0, 50 or 75%) of a mixture made up by a pea protein concentrate and wheat gluten. Fish meal quality did not affect (P>0.05) weight gain or feed efficiency in fish fed graded levels of plant protein in the diet. Feed intake decreased (P<0.05) as the level of plant protein was increased in the diet but this did not led to impaired growth or feed conversion rate. Protein efficiency and retention were equally improved (P<0.05) only with diets where a poor quality fish meal was substituted by protein rich-plant ingredients. Calculations based on the mass balance of nutrients of sea bass proven the inclusion of a mixture of highly purified plant-protein derivatives in complete diets for the sea bass, to be beneficial in reducing pollution load

    Effects of long term feeding diets differing in protein source and pre-slaughter starvation on biometry, qualitative traits and liver IGF-I expression in large rainbow trout

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    The effects of feeding two complete extruded diets differing in protein source (fish meal-FM vs. vegetable proteins-VP) over 30 weeks and subsequent 30 days of starvation on biometry, fillet composition and liver IGF-I mRNA were studied in large rainbow trout. At the end of the feeding period, the dietary protein source little affected major biometry traits, dressing out yields and overall adiposity (P>0.05) but fish given the VP diet resulted in higher content of PUFA n-6 fatty acids in mus- cle (0.46 vs. 0.22 g/100g fillet, P0.05) and of all fatty acids in fillet (P<0.05), except DHA. Liver IGF-I mRNA content was little affected by the test diet and starvation

    Functional fish: improving nutrition for the elderly

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    Elder people need highly digestible foods that can also provide health benefits even to those suffering from chronic diseases. Furthermore, such foods should be palatable as well as familiar for elder consumers. Fish is a high-protein, low-fat food that potentially provides a range of health promoting effects which may be further improved with suitable approaches in the production systems. The present mini-review intends to report possible aquaculture interventions to enhance the positive impact of fish on elder health and to promote its function in terms of prevention and recovery of specific diseases. Some fish species during their lifespan experience periods of food restrictions that can be mimicked in aquaculture without affecting fish welfare. Under these circumstances fish can modify the fatty acid profile and increase the use of muscle proteins to fulfill their energy requirements, by activation of muscle endogenous proteases. Degradation of muscle proteins can enhance their digestibility and possibly the release of encrypted bioactive peptides, showing a plethora of biological actions, including the antihypertensive activity. The degree of myofibrillar protein degradation and the fatty acid profile of fish fillet can then be managed by suitable and sustainable feeding protocols in the context of farming conditions

    Intestinal morpho-physiology and innate immune status of European sea bass (Dicentrarchus labrax) in response to diets including a blend of two marine microalgae, Tisochrysis lutea and Tetraselmis suecica

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    The aim of this study was to investigate the effects of replacing graded levels of dietary fish meal by a blend of two marine microalgae Tisochrysis lutea and Tetraselmis suecica on intestinal morpho-physiology and innate immune response in European sea bass. Two complete diets were formulated to be iso-nitrogenous and isolipidic and prepared by including a blend of the two microalgae, to replace approximately 15 and 45% fish meal protein of the control diet. A fourth diet, where the microalgae mix was substituted by soybean meal, was also prepared. Each diet was offered until visual satiety over 105 days to triplicated groups of European sea bass (204 \ub1 12.7 g), kept in a recirculating marine water system. The humoral and cellular innate immune parameters of E. sea bass were affected by the dietary treatment. Fish fed the microalgae-containing or the soybean rich diets, showed a significantly greater villi height, while the thickness of intestinal epithelium was significantly reduced in fish fed the soybean meal-rich diet. The activity of the brush border membrane enzymes, maltase, sucrase-isomaltase, \u3b3-glutamil transferase and alkaline phosphatase was not affected by dietary treatment but changed in different intestinal tracts. The genes sucrase-isomaltase, peptide transporter 1, sodium/potassium-transporting ATPase and aminopeptidase N were overexpressed in the pyloric and proximal region of the intestine of fish fed the microalgae-including diets. In conclusion, a blend of dried marine microalgae Tisochrysis lutea and Tetraselmis suecica as alternative ingredients to dietary fish meal did not hamper gut digestive-absorptive functions of E. sea bass. Moreover, it resulted in enhanced non-specific immune response, suggesting an effective role as an immunostimulant ingredien

    Linear Categorical Marginal Modeling of solicited symptoms in vaccine clinical trials

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    Analysis of the occurrence of adverse events, and in particular of solicited symptoms, following vaccination is often needed for the safety and benefit-risk evaluation of any candidate vaccine, and typically involves taking repeated measurements. In this article, it is shown that Linear Categorical Marginal Models (LCMMs) are well suited to take into account the dependencies in the data arising from the repeated measurements and provide detailed and useful information for comparing safety profiles of different products while remaining relatively easy to interpret. LCMMs are presented and applied to a Phase III clinical trial of a candidate meningococcal pediatric vaccine

    An overview on dietary polyphenols and their biopharmaceutical classification system (Bcs)

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    Polyphenols are natural organic compounds produced by plants, acting as antioxidants by reacting with ROS. These compounds are widely consumed in daily diet and many studies report several benefits to human health thanks to their bioavailability in humans. However, the digestion process of phenolic compounds is still not completely clear. Moreover, bioavailability is dependent on the metabolic phase of these compounds. The LogP value can be managed as a simplified measure of the lipophilicity of a substance ingested within the human body, which affects resultant absorption. The biopharmaceutical classification system (BCS), a method used to classify drugs intended for gastrointestinal absorption, correlates the solubility and permeability of the drug with both the rate and extent of oral absorption. BCS may be helpful to measure the bioactive constituents of foods, such as polyphenols, in order to understand their nutraceutical potential. There are many literature studies that focus on permeability, absorption, and bioavailability of polyphenols and their resultant metabolic byproducts, but there is still confusion about their respective LogP values and BCS classifi-cation. This review will provide an overview of the information regarding 10 dietarypolyphenols (ferulic acid, chlorogenic acid, rutin, quercetin, apigenin, cirsimaritin, daidzein, resveratrol, ellagic acid, and curcumin) and their association with the BCS classification

    Skin pigmentation in gilthead seabream (Sparus aurata l.) fed conventional and novel protein sources in diets deprived of fish meal

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    The pattern of yellowish pigmentation of the skin was assessed in gilthead seabream (Sparus aurata) fed for 12 weeks iso-proteic (45%) and iso-lipidic (20%) diets deprived of fish meal and containing either a blend of vegetable protein-rich ingredients or where graded levels of the vegetable protein blend were replaced by insect (Hermetia illucens\u201410%, 20% or 40%) pupae meal, poultry by-product meal (20%, 30% or 40%), red swamp crayfish meal (10%) and marine microalgae (Tisochrysis lutea and Tetraselmis suecica\u201410%) dried biomass. Digital images of fish fed diets differing in protein sources were analyzed by means of an automatic and non-invasive image analysis tool, in order to determine the number of yellow pixels and their dispersion on the frontal and lateral sides of the fish. The relationship between the total carotenoid concentration in the diet and the number of yellow pixels was investigated. Test diets differently affected gilthead seabream skin pigmentation both in the forefront and the operculum, due to their carotenoid content. The highest yellow pixels\u2019 number was observed with the diet containing microalgae. Fish fed poultry by-product meal were characterized by the lowest yellow pixels\u2019 number, diets containing insect meal had an intermediate coloring capacity. The vegetable control, the microalgae mix diet and the crayfish diet had significantly higher values of yellow pixels at both inspected skin sites

    Pea protein concentrate as a substitute for fish meal protein in sea bass diet

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    Pea seeds, even if lower in protein than oilseed meals, have been shown to successfully replace moderate amounts of fish meal protein in diets for carnivorous fish species (Kaushik et al., 1993, Gouveia and Davies, 2000). A further processing of such pulses provides concentrated protein products which look very promising as fish meal substitutes in aquafeeds (Thiessen et al., 2003). The aim of the present study was to evaluate nutrient digestibility, growth response, nutrient and energy retention efficiencies and whole body composition of sea bass (Dicentrarchus labrax, L.) fed complete diets in which a pea protein concentrate (PPC) was used to replace graded levels of fish meal protein
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