scholarly journals Phenylalanine and Tyrosine as Feed Additives for Reducing Stress and Enhancing Welfare in Gilthead Seabream and Meagre

Animals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 45
Author(s):  
Natalia Salamanca ◽  
Inmaculada Giráldez ◽  
Emilio Morales ◽  
Ignacio de La Rosa ◽  
Marcelino Herrera

Increased aquaculture production is associated with a growing interest in improving fish welfare. For this reason, the search for strategies to mitigate stress has intensified, one of these strategies being food supplementation with amino acids. The objective of this study was to evaluate the effects of dietary phenylalanine (Phe) and Tyrosine (Tyr) on the stress response and metabolism of juvenile gilthead seabreams (Sparus aurata) and meagres (Argyrosomus regius). Fish batches were fed a control diet and two diets supplemented with 5% Phe or Tyr for seven days. At the end of the experiment fish were stressed by air exposure for 3 min and then sacrificed for the extraction of blood and brain. Classical plasma stress markers were analyzed (glucose, lactate, proteins, cortisol), as well as hormones derived from those amino acids (adrenaline, noradrenaline and dopamine). Despite interspecific differences, fish fed the diets supplemented with Phe or Tyr showed a reduction on several stress markers. However, interspecific differences were detected for many indicators. Concretely, hormonal stress markers were significantly attenuated in meagres fed the enriched diets. Moreover, the stress condition favored a mobilization of amino acids towards the brain, especially in supplemented diets, hence this amino acid excess could be used as an energy substrate to cope with stress.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Erick Perera ◽  
David Sánchez-Ruiz ◽  
María Isabel Sáez ◽  
Alba Galafat ◽  
André Barany ◽  
...  

Abstract The aim of this work was to evaluate two functional feeds for the gilthead seabream, Sparus aurata, containing low inclusion of two microalgae-based products (LB-GREENboost, LBGb; and LB-GUThealth, LBGh). Fish (12–13 g) were fed for 13 weeks a control diet or one of the four diets supplemented with both products at 0.5% or 1%. LBGb and LBGh did not affect specific growth rate or survival, but increased feed efficiency by decreasing feed intake and enlarging the intestines. LBGb increased hepatosomatic index and reduced cortisol levels in plasma, while both products lowered plasma lactate. Extensive metabolite and metabolic enzyme profiling revealed that microalgae supplementations, especially 1% LBGh: (i) decrease plasma lactate and increase hepatic glycogen, (ii) reduce hepatic gluconeogenesis, (iii) enhance hepatic lipogenic activity and lipid secretion, (iv) led fish to double triglyceride content in muscle and to stimulate its lipid oxidative capacity, and (v) increase the content of monounsaturated fatty acids and the omega-3 alpha-linolenic acid in muscle. This study demonstrates that both microalgae-based products are suited to improve feed efficiency and orchestrate significant changes in the intermediary metabolism in gilthead seabream juveniles.


2021 ◽  
Vol 12 ◽  
Author(s):  
Joana P. Firmino ◽  
Eva Vallejos-Vidal ◽  
M. Carmen Balebona ◽  
Yuliaxis Ramayo-Caldas ◽  
Isabel M. Cerezo ◽  
...  

Essential oils (EOs) are promising alternatives to chemotherapeutics in animal production due to their immunostimulant, antimicrobial, and antioxidant properties, without associated environmental or hazardous side effects. In the present study, the modulation of the transcriptional immune response (microarray analysis) and microbiota [16S Ribosomal RNA (rRNA) sequencing] in the intestine of the euryhaline fish gilthead seabream (Sparus aurata) fed a dietary supplementation of garlic, carvacrol, and thymol EOs was evaluated. The transcriptomic functional analysis showed the regulation of genes related to processes of proteolysis and inflammatory modulation, immunity, transport and secretion, response to cyclic compounds, symbiosis, and RNA metabolism in fish fed the EOs-supplemented diet. Particularly, the activation of leukocytes, such as acidophilic granulocytes, was suggested to be the primary actors of the innate immune response promoted by the tested functional feed additive in the gut. Fish growth performance and gut microbiota alpha diversity indices were not affected, while dietary EOs promoted alterations in bacterial abundances in terms of phylum, class, and genus. Subtle, but significant alterations in microbiota composition, such as the decrease in Bacteroidia and Clostridia classes, were suggested to participate in the modulation of the intestine transcriptional immune profile observed in fish fed the EOs diet. Moreover, regarding microbiota functionality, increased bacterial sequences associated with glutathione and lipid metabolisms, among others, detected in fish fed the EOs supported the metabolic alterations suggested to potentially affect the observed immune-related transcriptional response. The overall results indicated that the tested dietary EOs may promote intestinal local immunity through the impact of the EOs on the host-microbial co-metabolism and consequent regulation of significant biological processes, evidencing the crosstalk between gut and microbiota in the inflammatory regulation upon administration of immunostimulant feed additives.


2021 ◽  
Vol 11 (19) ◽  
pp. 8806
Author(s):  
Pier Psofakis ◽  
Alexandra Meziti ◽  
Panagiotis Berillis ◽  
Eleni Mente ◽  
Konstantinos A. Kormas ◽  
...  

The effects on liver and intestinal histomorphology and on intestinal microbiota in gilthead seabream (Sparus aurata) fed diets that contained poultry by-product meal (PBM) and hydrolyzed feather meal (HFM) as fishmeal replacements were studied. Fish fed on a series of isonitrogenous and isoenergetic diets, where fishmeal protein of the control diet (FM diet) was replaced by either PBM or by HFM at 25%, 50% and 100% without amino acid supplementation (PBM25, PBM50, PBM100, HFM25, HFM50 and HFM100 diets) or supplemented with lysine and methionine (PBM25+, PBM50+, HFM25+ and HFM50+ diets). The use of PBM and HFM at 25% fishmeal replacement generated a similar hepatic histomorphology to FM-fed fish, indicating that both land animal proteins are highly digestible at low FM replacement levels. However, 50% and 100% FM replacement levels by either PBM or HFM resulted in pronounced hepatic alterations in fish with the latter causing more severe degradation of the liver. Dietary amino acid supplementation delivered an improved tissue histology signifying their importance at high FM replacement levels. Intestinal microbiota was dominated by Proteobacteria (58.8%) and Actinobacteria (32.4%) in all dietary groups, but no specific pattern was observed among them at any taxonomic level. This finding was probably driven by the high inter-individual variability observed.


Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 723
Author(s):  
Ewa Ziółkowska ◽  
Joanna Bogucka ◽  
Agata Dankowiakowska ◽  
Mateusz Rawski ◽  
Jan Mazurkiewicz ◽  
...  

The aim of the study was to evaluate the effects of a trans-galactooligosaccharide prebiotic (GOS) on the growth performance, biochemical blood parameters, and intestine morphometric parameters of common carp. The 60-day-long experiment was performed on one-year-old fish with a mean body weight of 180 g (±5 g). Three diets were used: control diet 1 (C) with no microbiota affecting feed additives, diet 2 (B1) with 1% of prebiotic, and diet 3 (B2) with 2% of prebiotic, in four replications (tanks) per treatment and 25 fish per tank. At the end of the trial, 16 individuals from each group were used for analyses. The study showed that GOS supplementation did not affect growth performance. In turn, the prebiotic had a positive effect on the development of the intestine, and increased the height, width, and surface of the villi in B1 and B2 groups. The content of phosphorus (P) was significantly higher in B1 group compared with B2 group, which indicated that 1% addition of prebiotic causes better absorption of P from the intestine. The other biochemical indicators—namely lipid, protein and hepatic parameters, insulin, and Ca—were not affected by GOS treatment, which may indicate similar metabolic balance of fish in each experimental group. Serum triiodothyronine (TT3) and glucose (stress markers) concentrations were not significantly different among treatments groups. GOS may be recommended as a feed additive for common carp due to its positive effects on fish physiology and development of the gastrointestinal tract. However, our results suggest that 1% diet supplementation causes satisfactory reactions for the abovementioned aspects in comparison to control or 2% supplementation.


Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1205
Author(s):  
Maria Chiara Cascarano ◽  
Orestis Stavrakidis-Zachou ◽  
Ivona Mladineo ◽  
Kim D. Thompson ◽  
Nikos Papandroulakis ◽  
...  

Climate change is expected to have a drastic effect on aquaculture worldwide. As we move forward with the agenda to increase and diversify aquaculture production, rising temperatures will have a progressively relevant impact on fish farming, linked to a multitude of issues associated with fish welfare. Temperature affects the physiology of both fish and pathogens, and has the potential to lead to significant increases in disease outbreaks within aquaculture systems, resulting in severe financial impacts. Significant shifts in future temperature regimes are projected for the Mediterranean Sea. We therefore aim to review and discuss the existing knowledge relating to disease outbreaks in the context of climate change in Mediterranean finfish aquaculture. The objective is to describe the effects of temperature on the physiology of both fish and pathogens, and moreover to list and discuss the principal diseases of the three main fish species farmed in the Mediterranean, namely gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax), and meagre (Argyrosomus regius). We will attempt to link the pathology of each disease to a specific temperature range, while discussing potential future disease threats associated with the available climate change trends for the Mediterranean Sea.


2020 ◽  
Author(s):  
Cláudia Raposo de Magalhães ◽  
Denise Schrama ◽  
Ana Paula Farinha ◽  
Dominique Revets ◽  
Annette Kuehn ◽  
...  

Abstract Background In the verge of getting a greater understanding of fish welfare, sensitive technological tools, such as proteomics, may assist the aquaculture industry as it allows an unbiased approach for the discovery of potential biomarkers for stress monitoring. Stress is characterized by a cascade of physiological responses that end-up inducing further changes at the whole-animal level that might either increase fitness or impair welfare. Monitorization of this dynamic process, up till now relies on indicators that are only a snapshot of the stress level experienced. Within this scope, using gilthead seabream ( Sparus aurata ) as a model, three chronic stress conditions, namely overcrowding, handling and hypoxia, were employed to evaluate the potential of the fish protein-based adaptations as reliable signatures of chronic stress, in contrast with the commonly used indicators of primary and secondary stress responses.Results A large spectrum of biological variation regarding cortisol and glucose levels was observed, which values rose higher in net handled fish. In this sense, a potential pattern of stressor-specificity was evidenced since the magnitude of response and tolerance varied markedly from a permanent (crowding) to a repetitive stressor (handling). Gel-based proteomics analysis of the plasma proteome also revealed that net handled fish had the highest number of proteins with significantly altered abundance, compared to the other trials, whereas mass spectrometric analysis, followed by gene ontology enrichment and protein-protein interaction analyses, characterized those as humoral components of the innate immune system and key elements on the response to stimulus.Conclusions Overall, this study represents the first screening of more reliable signatures of physiological adaptation to chronic stress in fish, allowing the future development of novel biomarker models to monitor fish welfare.


2022 ◽  
Vol 12 ◽  
Author(s):  
Mariana Ferreira ◽  
Pedro C. Ribeiro ◽  
Laura Ribeiro ◽  
Marisa Barata ◽  
Valentina F. Domingues ◽  
...  

Efforts have been made to find natural, highly nutritious alternatives to replace fish meal (FM) and fish oil (FO), which can simultaneously promote fish health and improve the nutritional quality of filets for human consumption. This study evaluated the impact of biofortified diets containing microalgae (as replacement for FM and FO), macroalgae (as natural source of iodine) and selenised yeast (organic source of selenium) on gilthead seabream growth, nutrient utilization, tissue composition and gene expression. A control diet (CTRL) with 15% FM and 5.5% FO was compared with three experimental diets (AD1, AD2, and AD3), where a microalgae blend (Chlorella sp., Tetraselmis sp., and DHA-rich Schizochytrium sp.) replaced 33% of FM. Diet AD1 contained 20% less FO. Diets were supplemented with Laminaria digitata (0.4% AD1 and AD2; 0.8% AD3) and selenised yeast (0.02% AD1 and AD2; 0.04% AD3). After feeding the experimental diets for 12 weeks, growth was similar in fish fed AD1, AD2, and CTRL, indicating that microalgae meal can partially replace both FM and FO in diets for seabream. But AD3 suppressed fish growth, suggesting that L. digitata and selenised yeast supplementation should be kept under 0.8 and 0.04%, respectively. Despite lower lipid intake and decreased PUFAs bioavailability in fish fed AD3, compared to CTRL, hepatic elovl5 was upregulated resulting in a significant increase of muscle EPA + DHA. Indeed, filets of fish fed AD2 and AD3 provided the highest EPA + DHA contents (0.7 g 100 g–1), that are well above the minimum recommended values for human consumption. Fish consuming the AD diets had a higher retention and gain of selenium, while iodine gain remained similar among diets. Upregulation of selenoproteins (gpx1, selk, and dio2) was observed in liver of fish fed AD1, but diets had limited impact on fish antioxidant status. Overall, results indicate that the tested microalgae are good sources of protein and lipids, with their LC-PUFAs being effectively accumulated in seabream muscle. Selenised yeast is a good fortification vehicle to increase selenium levels in fish, but efforts should be placed to find new strategies to fortify fish in iodine.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 677
Author(s):  
Basilio Randazzo ◽  
Matteo Zarantoniello ◽  
Gloriana Cardinaletti ◽  
Roberto Cerri ◽  
Elisabetta Giorgini ◽  
...  

The attempt to replace marine-derived ingredients for aquafeed formulation with plant-derived ones has met some limitations due to their negative side effects on many fish species. In this context, finding new, sustainable ingredients able to promote fish welfare is currently under exploration. In the present study, poultry by-products and Hermetia illucens meal were used to replace the vegetable protein fraction in diets totally deprived of fish meal intended for gilthead seabream (Sparus aurata). After a 12-week feeding trial, a multidisciplinary approach including histological, molecular, and spectroscopic techniques was adopted to investigate intestine and liver responses to the different dietary formulations. Regardless of the alternative ingredient used, the reduction in dietary vegetable proteins resulted in a lower incidence of intestine histological alterations and inflammatory responses. In addition, the dietary inclusion of insect meal positively affected the reduction in the molecular inflammatory markers analyzed. Spectroscopic analyses showed that poultry by-product meal improved lipid absorption in the intestine, while insect meal induced increased liver lipid deposition in fish. The results obtained demonstrated that both poultry by-products and H. illucens meal can successfully be used to replace plant-derived ingredients in diets for gilthead seabream, promoting healthy aquaculture.


Sign in / Sign up

Export Citation Format

Share Document