The fine art of protection

Transcription

1 The fine art of protection NEW Protec is Skretting s prime functional feed for farmed fish. New Protec helps to shield skin, gut and gills; it supports the immune system, provides building blocks for new cells and optimises the balance between fish, microbes and environment.

2 Shield 1 Together, the outer surfaces of the fish; the skin, gut and gills, make an effective shield from environmental impacts. Protec helps strengthen these essential barriers.

3 Gills The gills comprise a large surface area of delicate cells that play a crucial role for the fish s respiration, osmoregulation and excretion. Protec supports immunity of the gills and aids mucous cell recovery. 2 Skin The skin with its mucus layer provides both a physical barrier and is a crucial component of immune defences. The skin faces a number of challenges including bacteria, parasites, chemicals and physical trauma. New Protec further supports the skin s natural functions, defences and healing processes. Gut Even though the gut is located within the fish, it can be considered an external barrier. The gut can be damaged by pathogenic, chemical, traumatic or environmental stress. Protec improves gut structure, and through this assists digestive functions and resilience to pathogens Scanning electron micrograph of fish gills. 2. Scanning electron micrograph of fish skin surface. 3. Area of salmon gut stained to highlight structures.

4 9 Relative % expression Relative chemokine expression in Atlantic salmon 6 hours post wound healing. NEW Trials show over 8x more immune activity (chemokine expression) in connection with lesion healing when using New Protec compared with the group. Skin chemokines attract immune cells (neutrophils, macrophages, lymphocytes), have antimicrobial activities, host defence molecules, limit cell damage and aid in the repair of blood vessels, in wound repair and remodelling. 72 Epidermal thickness (µm) o C 1 o C 16 o C Epidermal thickness was increased in fish fed Protec, particularly at extreme water temperatures. Epidermal thickness of Atlantic salmon at different water temperatures. Mean mucous cell area in the outer 1 um of tissue relative to tissue area (%) pretreatment eatment 4 4 hours hr hours hr 3 days 7 days 14 days 28 days posttreatment Average mucous cell area following hydrogen peroxide (H 2 O 2 ) bathing. Before H 2 O 2 treatment, there are more full mucous cells in the outer skin layer of the Protec group. The levels stay more consistent with Protec than with the diet. In the group, levels fluctuate more (approx. 2x) in response to the chemical trauma. The Protec group shows a more steady state of maintaining a regular number of mucous cells, ready to discharge contents to the skin surface.

5 16 Relative % expression IgM IgT Relative immunoglobulin expression in Atlantic salmon gills. NEW Up-regulation of immunoglobulin (IgM, IgT) expression in gills of fish fed New Protec. Immunoglobulins are antibodies which are used by the immune system to identify and neutralise foreign objects such as bacteria and viruses: IgM - systemic antibodies; IgT - newly described secretory antibodies, important in mucosal (local) immunity. % EGC area (mean +/- SEM) % perimeter/area (mean +/- SEM) Protec increases the gut perimeter and lowers the level of inflammatory cells (eosinophilic granule cells, EGCs). 1 ve Negative Protec Quantitative gut histology in Atlantic salmon. 1. Negative Quantitative gut histology in Atlantic salmon. Graphic demonstration of Protec s ability to reduce the presence of eosinophilic granule cells (EGCs, red), and increase the gut perimeter area (blue), in relation to total gut area (green). EGCs are important contributors to the inflammatory process and innate immunity in fish. They are widely distributed but predominantly found in the gastrointestinal tract and the gills. Their granules contain antimicrobial substances involved in non-specific defence mechanisms.

6 Support 1 The fish s defence system is dependent on a strong immune response. Protec strongly supports immune functions while limiting oxidative stress and through this contributes to reduce inflammation. Protec also supplies building blocks for new cells.

7 The immune system Fish possess complex immune mechanisms. The defences can be challenged by infectious agents, trauma and environmental stress. Protec supports the critical processes of the immune system. Cell regeneration Metabolic and immune processes demand high turnover of cells. Protec provides building blocks for new cells which are necessary for optimal fish health. 2 Anti-oxidative Unregulated cellular defence processes can lead to tissue damage through oxidative stress and uncontrolled inflammation. Protec supplies antioxidants to counter excessive oxidation and supports innate fish defences Tissue macrophage with short filopodia. 2. Fluorescent micrograph of a cell during metaphase. 3. Polarised micrograph of vitamin C crystals.

8 17 a 6.6 a Blood lactate (mmol/l) % b Blood glucose (mmol/l) % b Fish fed Protec had significantly less of these secondary stress parameters than the fish. Different letters denote a significant difference among diets (p<.1) Blood lactate and glucose levels in Tasmanian Atlantic salmon parr one hour post stress. Relative % blood lactate increase % Relative % blood glucose increase % Fish fed Protec had 24 and 3% less of these secondary stress parameters than the fish. Relative increase (compared to basal levels) of blood glucose and lactate in Australian barramundi following a stress event. Relative % increase in liver vitamin E Australian 1 New Zealand 2 barramundi Chinook salmon Relative increase in liver vitamin E (alpha-tocopherol) in Australian barramundi and New Zealand Chinook salmon fed Protec for at least 4 weeks during winter and summer, respectively (compared to fish fed diets). Protec significantly increases the amount of vitamin E stored in the liver. This in turn leads to increased antioxidative capacity in the fish.

9 Cumulative mortality (%) Vaccine Protec unvaccinated vaccinated unvaccinated vaccinated Fish fed Protec for 6 weeks preand 6 weeks post-vaccination, followed by challenge had the lowest mortality Days post challenge Cumulative mortality of Atlantic salmon challenged with Infectious salmon anaemia (ISA). Cumulative mortality (%) Vaccine Protec unvaccinated vaccinated unvaccinated vaccinated Fish fed Protec for 6 weeks preand 6 weeks post-vaccination, followed by challenge had the lowest mortality Days post challenge Cumulative mortality of Atlantic salmon challenged with Moritella viscosa (winter sores). Average weight (g) /8/1 2/1/1 2/12/1 31/3/11 24/5/11 26/7/11 Performance of sea bream grown over a Northern Hemisphere winter. unvaccinated vaccinated unvaccinated vaccinated From the onset of autumn and then winter, Protec outperformed the diet in relation to weight gain and, in the final weight check Protec groups were on average 24% larger than the.

10 Balance 1 Fish live in a potentially threatening environment and are vulnerable to critical changes in the surroundings. Protec contributes positively to maintain the complex balance between fish, hostile microbes and environment.

11 Virus Despite their tiny dimensions, viruses pose one of the greatest threats to fish health. Among the thousands of described viruses, many exist in aquatic systems where they can infect fish. New Protec has been formulated to favour fish in their delicate balance with viruses. 2 Parasites Parasites have always been part of the natural environment and can evade fish defence mechanisms. Protec supports immunological and structural mechanisms to tip the balance in favour of the fish in their battle with parasites. Bacteria Bacteria are always present both in the water surrounding fish and within their intestines. While some cause disease, others are crucial for fish welfare. Protec supports the balance between fish and these populations Stylised scanning electron micrograph of an enveloped virus. 2. Amoeba with extended pseudopods. 3. Scanning electron micrograph of bacteria from intestinal microbiota.

12 Cumulative mortality (%) Days post challenge Cumulative mortality of Atlantic salmon challenged with Pancreas disease (PD). unvaccinated vaccinated unvaccinated vaccinated Protec fed for 4 weeks pre- and 6 weeks post-challenge helped reduce the mortality levels by 7%. When Protec was combined with a PD vaccination, mortality was reduced by 85%. Plasma CRP (mg/l) Days post challenge Plasma C-Reactive Protein (CRP) in Atlantic salmon challenged with Pancreas disease (PD) unvaccinated vaccinated unvaccinated vaccinated Protec fed for 4 weeks pre- and 6 weeks post-challenge helped reduce the level of CRP. Plasma CRP is an acute phase protein found in the blood. Levels rise in response to inflammation. Therefore, CRP is used mainly as a marker of acute inflammation. Plasma creatine kinase (U/L) % 32% NEW Fish fed Protec and New Protec had less of this indicator of muscle damage than the fish. Plasma creatine kinase of Atlantic salmon infected with Cardiomyopathy syndrome (CMS).

13 % Survival mortality = 67.1% b RPS = 27.1% b RPS = 26.8% Days post challenge Survival of Tasmanian Atlantic salmon smolt challenged with Neoparamoeba perurans, the causative agent of AGD. a Test Diet 1 Test Diet 2 Fish fed Protec based test diets had 27% improved relative survival compared to fish fed the diet. Different letters denote a significant difference among diets (p<.1). * Relative percentage survival (RPS) is calculated by the formula RPS = (1-(%mortality/%control mortality)) x 1, (Amend, 1981) 176 a Blood sodium (mmol/l) b Blood sodium of Tasmanian Atlantic salmon smolt challenged with Neoparamoeba perurans, at the conclusion of the trial (31 days post challenge). b Test Diet 1 Test Diet 2 Fish fed Protec-based test diets had significantly reduced blood sodium concentrations compared to fish fed the diet. This suggests optimised osmoregulation in fish fed the test diets. Different letters denote a significant difference among diets (p<.5) Cumulative mortality (%) NEW Fish fed New Protec had 23% less cumulative mortality than the fish Days post challenge Cumulative mortality of sea bass challenged with Viral nervous necrosis (VNN).

14 Relative % virus replication (in vitro) Viruses alone NodaV + New Protec Series1 IPNV + New Protec SAV3 + New Protec New Protec significantly inhibits virus replication in vitro. NEW Nodavirus (Viral nervous necrosis, VNN in sea bass), IPN Virus (Infectious pancreatic necrosis in salmon), SAV3 (Pancreas disease, PD in salmon). Microbe Association MIC (ppm) Flavobacterium psychrophilum Rainbow Trout Fry Syndrome (RTFS) 2 Piscirickettsia salmonis Salmon Rickettsiai Syndrome (SRS) 23.5 Vibrio salmonicida Cold Water Disease 25 Photobacterium damselae subsp. piscicida Pasteurellosis 45 Pseudomonas anguilliseptica Winter Disease Sea bream 25-5 Moritella viscosa Winter Sores Salmon 5 Aeromonas salmonicida subsp. salmonicida Furunculosis 9 Vibrio vulnificus Vibriosis Edwardsiella tarda Edwardsiellosis 13 Listonella anguillarum serotype O1 Vibriosis 12 Yersinia ruckeri serotype I Yersiniosis (Enteric Red Mouth Disease) 2 Lactococcus lactis subsp. lactis Lactic acid bacteria 3 Lactobacillus plantarum Lactic acid bacteria 55 Carnobacterium divergens Lactic acid bacteria 3 In vitro assessment of inhibitory effects of Protec ingredients on key aquatic bacteria (Dept. of Microbiology & Ecology, University of Valencia, Spain). Protec significantly inhibits bacterial growth in vitro. Minimum Inhibitory Concentration (MIC) of Protec ingredients. The lower the value the better the inhibition. Note: beneficial Lactic acid bacteria (grey) are not inhibited at concentrations below 3ppm.

15 Protec recommendations To get the best out of Protec feeds it is recommended to follow a structured and site specific feeding regime. Aim to start feeding in advance of planned operations and risk periods. Use Protec before stress events; to enhance vaccination efficacy; through disease risk periods; during disease events without efficacious treatments during environmental insults which increase mortality rates Feed Protec for at least 2 to 4 weeks prior to anticipated stress (grading, vaccination, transport, treatment), and for 2 to 4 weeks post-stress; for at least 4 weeks prior to the anticipated onset of disease, then throughout the exposure and disease period; at the onset of environmental insults and challenges (algae, jellyfish, low oxygen) until the resolution of the event. Recommendations for Protec use in UK salmonid production GRADING VACCINATION GRADING weight (g) ENVIRONMENTAL INSULTS GROWOUT

16 Skretting is a world leading producer and supplier of feed for farmed fish and shrimp. Total annual production of high quality feeds is approximately 1.7 million tonnes. Skretting has operating companies in five continents to produce and deliver feeds, from hatching to harvest, for more than 6 species of farmed fish and shrimp.