27 research outputs found

    The assessment of selected novel feed ingredients to replace fishmeal on the nutrition and health status of ornamental fish

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    Chapter 3 has been published in the Journal of Fish and Shellfish immunology and Chapter 5 has been published in the Journal of AquacultureFour investigations were conducted to assess the effects of feeding selected novel feed ingredients on the nutrition and health status of ornamental fish. Each dietary ingredient was assessed by determining the effects on growth performance, feed utilisation, haematological status, serological status and immuno-competence of mirror carp, a model ornamental fish species. The first experiment was conducted to evaluate the effect of feeding a tropical earthworm meal (Perionyx escavatus) and soybean meal on the haemato-immunological response and growth performance of mirror carp (Cyprinus carpio). Fish were fed diets for a total of 88 days, fishmeal served as the main protein source in the control diet. Two remaining diets consisted of fishmeal fixed at 33 % provision of protein and the remaining 66 % protein was provided by soybean meal (SBM diet) or P. excavatus meal (EW diet). After 60 days of feeding fish fed EW diet showed a significant elevation in final body weight compared to fish fed a fishmeal diet and fish fed a SBM diet. Similar improvements were observed in feed utilisation efficiency. After intraperitoneal injection with heat inactivated Aeromonas hydrophila and 28 days of feeding EW diet to mirror carp showed decrease in some aspects of the innate immune response. Contrary to this, fish fed soybean meal showed signs of inflammation. The second experiment was conducted to evaluate the effect of feeding two plant protein concentrates and a combination of whey protein concentrate and casein protein on the growth performance, haematological and serological responses of mirror carp (C. carpio). Fish were fed diets for a total of 84 days, fishmeal served as the main protein source in the control diet. Three remaining diets consisted of fishmeal fixed at 33% provision of protein and the remaining 66% protein was provided by rice protein concentrate (RPC diet), corn protein concentrate (CPC) and a combination of whey protein concentrate (8%) and casein protein (58%) (WPC diet). After 84 days of feeding fish fed WPC diet showed a significant elevation in final body weight compared to fish fed a fishmeal diet and fish fed RPC and CPC diets. Similar improvements were observed in feed utilisation and protein efficiency. At the end of the trial feeding fish fed WPC diet showed a significant elevation in mean corpuscular haemoglobin levels compared to fish fed fishmeal and RPC diets. Serological analysis showed that feeding carp the WPC showed a significant increase in serum albumin and protein concentrations compared to fish fed fishmeal diet. The final experiment was conducted to evaluate the effect of feeding selected exotic ingredients on immune responses and expression of immune related genes in mirror carp (C. carpio). Fish were fed diets for a total of 63 days. Fishmeal served as the main protein source in the control diet and two experimental diets consisted of fishmeal fixed at 34% provision of protein and the remaining protein was provided either by earthworm meal (EW diet) or a combination of whey protein concentrate (8%) and casein (58 %) (WPC diet). At the start of the trial fish were injected intraperitoneally with A. hydrophila bacterin. Compared to fish fed fishmeal, a significant increase in mRNA expression of the pro-inflammatory cytokines IL-1β (24 h post injection) and TNFα (at 12 h and 48 h post injection) was observed in fish fed EW. Moreover a similar trend was observed for complement 3 (C3) gene, where fish fed EW showed significant elevations in mRNA expression values at both 12 and 48 h post injection compared to control fed fish. In contrast, fish fed WPC showed a significant decrease in C3 and TNF-α mRNA expression compared to fish fed fishmeal (48 h post injection). Fish fed EW and WPC diet showed a significant increase leukocyte levels compared to fish fed fishmeal 14 days post injection. Fish fed fishmeal presented significantly higher circulatory IgM levels at 7 d post injection compared to fish fed EW and WPC diets. In contrast, fish fed EW and WPC showed a significant increase in IgM levels at 28 d post injection. This study concludes that feeding fish non-plant based feed commodities had a positive effect on carp growth response, feed utilisation and immuno-competence. These findings are both novel and highly relevant for the ornamental industry where high value feed commodities are more acceptable.Biotechnology and Biological Sciences Research Council (BBSRC)and MARS Waltham Centre For Pet Car and Nutritio

    Yeast cell wall extracts from Saccharomyces cerevisiae varying in structure and composition differentially shape the innate immunity and mucosal tissue responses of the intestine of zebrafish (Danio rerio)

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    With the rising awareness of antimicrobial resistance, the development and use of functional feed additives (FFAs) as an alternative prophylactic approach to improve animal health and performance is increasing. Although the FFAs from yeasts are widely used in animal and human pharma applications already, the success of future candidates resides in linking their structural functional properties to their efficacy in vivo. Herein, this study aimed to characterise the biochemical and molecular properties of four proprietary yeast cell wall extracts from S. cerevisiae in relation to their potential effect on the intestinal immune responses when given orally. Dietary supplementation of the YCW fractions identified that the α-mannan content was a potent driver of mucus cell and intraepithelial lymphocyte hyperplasia within the intestinal mucosal tissue. Furthermore, the differences in α-mannan and β-1,3-glucans chain lengths of each YCW fraction affected their capacity to be recognised by different PRRs. As a result, this affected the downstream signalling and shaping of the innate cytokine milieu to elicit the preferential mobilisation of effector T-helper cell subsets namely Th17, Th1, Tr1 and FoxP3+-Tregs. Together these findings demonstrate the importance of characterising the molecular and biochemical properties of YCW fractions when assessing and concluding their immune potential. Additionally, this study offers novel perspectives in the development specific YCW fractions derived from S. cerievisae for use in precision animal feeds

    Dietary supplementation with a specific mannan-rich yeast parietal fraction enhances the gut and skin mucosal barriers of Atlantic salmon (Salmo salar) and reduces its susceptibility to sea lice (Lepeophtheirus salmonis)

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    Background: Increasing reliance on non-medicinal interventions to control sea lice in the Atlantic salmon (Salmo salar) farming industry imposes a high level of skin mucosal disturbance and indirect health issues. Dietary supplementation with yeast-based MOS products is widely used to support intestinal homeostasis across farmed species. Evidence of their effect on skin mucosa is increasing in aquatic species but it remains inconsistent and someway short of a clear contribution to sea lice management. A tank-based trial was performed to test the effect of a yeast-based MOS functional compound (sMOS) on the skin mucosal layer and its protective effects against sea lice (Lepeophtheirus salmonis). Results: The test compound significantly increased skin mucus (+46%) and goblet cell density (+25%) after 6 weeks of dietary supplementation when positive effects on intestinal villi-length (+10.9%) and goblet cell density (+80.0%) were also documented. Following dietary supplementation, a 16.6% reduction in susceptibility to an acute standard copepodid challenge was measured alongside an earlier increase in skin lysozyme activity widely used as an index of innate immunity. Conclusion: The study provides functional evidence that the benefits of dietary sMOS reach beyond the intestine to the skin mucosa. Bolstering of the Atlantic salmon skin barrier and immune functions and the resulting lower susceptibility to sea lice has the potential to reduce the need for delousing interventions and the impact of non-medicinal interventions on the animal's health and welfare

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Measurement of the inclusive isolated-photon cross section in pp collisions at √s = 13 TeV using 36 fb−1 of ATLAS data

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    The differential cross section for isolated-photon production in pp collisions is measured at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC using an integrated luminosity of 36.1 fb. The differential cross section is presented as a function of the photon transverse energy in different regions of photon pseudorapidity. The differential cross section as a function of the absolute value of the photon pseudorapidity is also presented in different regions of photon transverse energy. Next-to-leading-order QCD calculations from Jetphox and Sherpa as well as next-to-next-to-leading-order QCD calculations from Nnlojet are compared with the measurement, using several parameterisations of the proton parton distribution functions. The predictions provide a good description of the data within the experimental and theoretical uncertainties. [Figure not available: see fulltext.

    Measurement of jet fragmentation in Pb+Pb and pppp collisions at sNN=2.76\sqrt{{s_\mathrm{NN}}} = 2.76 TeV with the ATLAS detector at the LHC

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    Potential performance of parallel conservative simulation of VLSI circuits and systems

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    The deterministic nature of conservative simulation makes it possible to conduct an accurate trace-driven analysis of an existing sequential simulator in order to predict concurrency profiles and speedup bounds for several parallel implementations. This paper describes such an analysis carried out on a commercial VLSI digital circuit simulator with results based on real instance evaluation times at microsecond resolutions. We consider a central event queue based model with and without lookahead, as well as the distributed message passing model. The results help to answer the important questions, 'Just how much concurrency is there in real commercial VLSI simulations?" and "What type of machine would be best suited for a parallel implementation?"

    Potential performance of parallel conservative simulation of VLSI circuits and systems

    No full text
    The deterministic nature of conservative simulation makes it possible to conduct an accurate trace-driven analysis of an existing sequential simulator in order to predict concurrency profiles and speedup bounds for several parallel implementations. This paper describes such an analysis carried out on a commercial VLSI digital circuit simulator with results based on real instance evaluation times at microsend resolutions. We consider a central event queue based model with and without lookahead, as well as the distributed message passing model. The results help to answer the important questions, 'Just how much concurrency is there in real commercial VLSI simulations?' and 'What type of machine would be best suited for a parallel implementation?

    Modulation of Zebrafish (Danio rerio) Intestinal Mucosal Barrier Function Fed Different Postbiotics and a Probiotic from Lactobacilli

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    It is generally accepted that microbes play a critical role in maintaining gut barrier function, making them ideal to target in order to mitigate the effects of intestinal diseases such as inflammatory bowel disease with specialist supplementations such as probiotic or postbiotic preparations. In this study, specific strains of Lactobacillus helvictus both live and inactivated and Lactobacillus plantarum inactivated were fed to zebrafish at an inclusion level of 6 × 106 cells/g in order to assess the effects on gut barrier function and protection. Taken together, our results indicate that dietary administration of pro- or postbiotics strengthens the gut barrier function and innate immunity of healthy zebrafish in a strain-specific and process-dependent way. With some differences in the response intensity, the three treatments led to increased intestinal villi length and proportion of IELs, reinforcement of the GC population and up-regulated expression of biomarkers of AMP production and tight junction zona-occludin 2a (zo-2a). In addition, LPPost had an impact on the adaptive immune response, and we hypothesized that it conferred the potential to drive Th17/ILC3 immunity, as suggested by its effect on the gene expression of il22, of different AMPs, and the expression of zo2a. Moreover, LPPost showed the potential to drive Th1/ILC1-like immunity, with a higher percentage of CD8+ cells and higher ifnγ gene expression. In summary, the use of inactivated Lactobacilli species in this study represented a promising strategy for improving barrier function and regulating the immune fate of the intestinal mucosa in a strain-specific way
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