POSTER - ABSTRACT. Nettverksmøte Høgskolen i Bodø og Radisson Blu Hotel. Konferansen støttes av:

Transkript

1 2010 POSTER - ABSTRACT Nettverksmøte 2010 Høgskolen i Bodø og Radisson Blu Hotel Konferansen støttes av:

2 Innhold Screening of probiotic candidates from the gut microbiota of Atlantic cod... 3 Compensatory growth in juvenile Atlantic cod... 4 Hydrolysed lipids in Atlantic cod larvae diet... 5 Establishing a link between vaccination and immunity in Atlantic cod, Gadus morhua: The case of Vibrio anguillarum... 6 Oral administration of antibiotics modulates immune response and antioxidant defense in Atlantic cod... 7 Comparison of injection vaccines in cod; effect on growth and side effects... 8 Low space demanding packaging method (Super MAP) prolongs shelf life of farmed cod fillets Continuous light versus photoperiod: effects on eye size and deformities in larval and juvenile cod Natural zooplankton -live feed of the future?... 11

3 Screening of probiotic candidates from the gut microbiota of Atlantic cod C.M.A. Caipang, M.F. Brinchmann, V. Kiron Faculty of Biosciences and Aquaculture, Bodø University College, 8049 Bodø, Norway Four bacteria isolated from the intestinal tract of wild-caught Atlantic cod, Gadus morhua were found to have high similarity to Psychrobacter sp. (GP11), Shewanella sp. (GS11), Photobacterium sp. (GP31) and Vibrio sp. (GV11) based on the 16S ribosomal DNA gene sequence analysis. These bacteria were tested for their antagonistic activity against Vibrio anguillarum and Aeromonas salmonicida, two common bacterial pathogens, using well diffusion agar assay. They were not similar in their inhibitory action against the target pathogens - an enhanced activity was observed for strains GP11 and GS11 at the highest incubation temperature. In a preliminary effort to understand the extent of their influence on the immune system, head kidney leucocytes from healthy cod were exposed to the heatinactivated gut bacteria; the genes related to bacterial defense and inflammation were found to be differentially regulated. The results suggest that some of the isolates from the gut microbiota have potentially greater probiotic capabilities than the rest.

4 Compensatory growth in juvenile Atlantic cod Hanssen, H., Powell, M., Foss, A., Vikingstad, E., Bjørnevik, M. og Imsland, A. NFR prosjektet Growt, maturation, and flesh quality control in on-growing Atlantic cod in the North Norway region (NORTHERNCOD) forsøker å etablere nye produksjonsmetoder for å kunne kontrollere kjønnsmodning, øke vekst, redusere fôr og lønnskostnader ved å bruke en kombinasjon av spesielt designet faste-refôrings perioder (syklisk fôring) og fotoperiode regimer. Effekt av disse regimene på vekst, kjønnsmodning, muskelkvalitet og avkastning vil bli studert for å finne ut hvilke regimer som gir best resultat. Prosjektet tar sikte på å identifisere hvordan faktorer knyttet til sesong, vekstrate, fiskestørrelse, kjønnsmodning og kjønn påvirker sluttkvaliteten. Dette for å oppnå bedre forståelse av hvordan sesong og produksjonsforhold påvirker vekstdynamikk og påfølgende effekt på muskelbiomasse og - kvalitet. Forsøk 1 har tittelen Compensatory growth in juvenile cod og pågikk i Bodø januar 09 mai 09. Forsøk 2 The effect of photoperiod on growth and maturation of cod pågår nå i Brønnøysund i perioden oktober 2009 november Forsøk 3 Optimizing flesh quality in cod culture avsluttes november Resultater fra forsøk 1 vil bli presentert som poster. I dette forsøket ble liten torsk (133 gram) gitt 5 ulike fôringsregimer (kontrollgruppe med normal fôring (100 %) fra tabell, fôring annen hver dag, 50% fôring i 2 uker med påfølgende 4 uker normal fôring, sult i 1 uke med påfølgende 2 uker normal fôring og sult i 2 uker med påfølgende 4 uker normal fôring) fra januar til mai. Kompensasjonsvekst er tidligere observert i flere marine fiskearter f.eks piggvar (Sæther og Jobling, 1999), kveite (Heide et al. 2006, Foss et al. 2009), og steinbit (Foss og Imsland, 2002). Hovedmålet er å oppnå bedre eller like god vekst (reduserte fôr kostnader) i gruppene med faste og re-fôrings perioder som det observeres i kontrollgruppen. Resultatene viser at kompensasjonsvekst hos torsk på dette stadiet sultet i en og to uker, ikke ble funnet. Derimot fant vi at torsk fôret annen hver dag vokste like godt som kontrollgruppen. Samarbeidspartnere i forsøket er Fjord Marin Cod AS Brønnøysund, Akvaplan-Niva Tromsø, Nofima Norconserv - Stavanger, Fakultet for biovitenskap og akvakultur, Høgskolen i Bodø, Bodø og Havforskningsinstituttet Austevoll.

5 Hydrolysed lipids in Atlantic cod larvae diet Øystein Sæle 1, Andreas Nordgreen 1, Pål A. Olsvik 1, Jan Idar Hjelle 1, Torstein Harboe 2 and Kristin Hamre 1 1 : NIFES, Strandgaten 229, 5004 Bergen, Norway 2 : Institute of Marine Research, Austevoll, 5392 Storebø, Norway In larval protein nutrition, the use of pre-digested protein has been extensively used to study the underlying mechanisms and the limiting factors of protein digestion. Pre-digested protein is absorbed at a higher rate than intact protein in Atlantic halibut larvae and the inclusion of pre-digested protein in formulated diets for marine fish larvae has been found to be beneficial up to a certain level in most species. Similarly, we have found that Atlantic halibut larvae absorb a larger fraction of dietary MAG than TAG, 90 vs 34% after 18 hours incubation in tube fed larvae. DAG and PL were absorbed at intermediate rates. It is not known whether lyophospholipid (lpl) is absorbed to a greater extent than intact PL or if addition of predigested lipid to diets for marine fish larvae will improve larval performance. Diet TAG DAG FFA PL lpl SM CHOL Ukjent We fed 30 days post hatch (dph) old Atlantic cod larvae six diets with different degrees of hydrolyzed lipids for 30 days to investigate the long term effect on FFA in the diet. The different diets did not have any effect on growth, but there was a positive correlation between the level of FFA in the diets and mortality in the trial units. Cyp4 was regulated at the genetic level, according to FFA levels in the diets after 30 days of feeding, but not 15. The CYP4 family is associated with a detoxification process needed to reduce accumulation of free fatty acids in cells (Ada et al., 1999). Response elements to lipids, such as peroxisome proliferator-activated receptors (PPARs), liver X receptor (LXR) and genes involved in redox such as Glutathione reductase, Glutathione peroxidase, Superoxide dismutases and Mitogen-activated protein kinase did not show any sign of regulation by diet at 45 dph, when the larvae had been fed the test diets for 15 days. After 30 days of trial diets, on the other hand, the response was clear. These genes were unregulated in larvae fed diet 2 and 3, containing 16 and 23 % FFA but no lpl. In larvae fed diets 4 and 5, containing 24 and 28 % FFA but 5 % lpl in addition, the same genes were down regulated. All larvae fed the diet with 35 % FFA and 5 % lpl were dead at this point. We here demonstrate the toxic effect of FFA on Atlantic cod larvae, introduced in the diet. Despite of indications of a positive effect in earlier experiments we here demonstrate that the toxicity is not acute but needs time to accumulate. Perhaps most surprisingly is the lack of positive effect at the low levels FFA.

6 Establishing a link between vaccination and immunity in Atlantic cod, Gadus morhua: The case of Vibrio anguillarum C.M.A. Caipang, M.F. Brinchmann, K. Korsnes, V. Kiron Faculty of Biosciences and Aquaculture, Bodø University College, 8049 Bodø, Norway Vibrio anguillarum serotypes O2 and O2 are commonly associated with vibriosis in Atlantic cod, Gadus morhua. Vaccines have protected this fish from the disease, but it is known that individual responses vary widely and that the cod immune system differentiates between V. anguillarum serotypes. It is possible that other components of the immune system too would contribute to the protective immunity. In order to gain more knowledge on this aspect, we characterized the expression of certain immune-related genes in the blood and spleen of Atlantic cod ( g) at 1, 3, 7 days (dpv) following intraperitoneal vaccination with heat-killed V. anguillarum (serotype O2). In the blood, majority of the immune-related genes were immediately upregulated as early as 1 dpv and the levels were maintained for at least a week post-vaccination. A similar upregulation of these genes in the spleen, particularly those related to antibacterial activity indicates that they too may be linked to acute phase response of fish. The increased transcription of antioxidant-related genes corresponded to the activation of this defense process in the vaccinated fish. The reduction of bacterial population by sera from the vaccinated fish implies that the aforementioned factors contributed to the suppression of the pathogen proliferation. The information gathered could improve our understanding of the immune responses of fish and help in devising better vaccines and suitable delivery methods.

7 Oral administration of antibiotics modulates immune response and antioxidant defense in Atlantic cod C.M.A. Caipang, M.F. Brinchmann, K. Korsnes, V. Kiron Faculty of Biosciences and Aquaculture, Bodø University College, 8049 Bodø, Norway Oxolinic acid and florfenicol are antibacterial agents that are commonly used against diseases of Atlantic cod, Gadus morhua. In this study we examined the changes in immune responses and bacterial proliferation in serum (in vitro) upon oral administration of these two agents [florfenicol 10 mg - or oxolinic acid 20 mg- active ingredient kg 1 fish at 0.5% bw. for 10 days] on cod. For this, whole blood and serum samples were collected on the 10th day of feeding the antibiotics and at 3, 5 and 10 days after their withdrawal (daw). Considering the innate humoral immune responses, florfenicol caused an increase in serum alkaline phosphatase (ALP) activity compared to the control group, which lasted until10 daw. The serum myeloperoxidase activity was not affected, except for a reduction at 3 daw. Oxolonic acid did not show any change, but for an elevation of ALP at 5 daw. The transcriptional profiles of selected genes linked to bacterial defense, inflammation and antioxidant defense exhibited patterns related to the antibiotics and sampling point in most cases a significant change was observed upon feeding for 10 days. The counts of Vibrio anguillarum and Aeromonas salmonicida were significantly lower when tested with sera from the antibiotic-fed fish, until 5 daw. The inhibition of V. anguillarum was greater with florfenicol than with oxolinic acid, while A. salmonicida was susceptible to both antibiotics. Thus oral administration of antibiotics modulates the immune response and antioxidant defense in Atlantic cod and these may, in turn, affect their ability to resist bacterial pathogens.

8 Comparison of injection vaccines in cod; effect on growth and side effects. Ragnhild Hanche Olsen 1, Arve Nilsen 2, Anja Bråthen Kristoffersen 3 1: Helgeland Havbruksstasjon 2: Veterinærinstituttet, Seksjon for miljø og smittetiltak, Trondheim 3: Veterinærinstituttet, Seksjon for epidemiologi, Oslo Classical Vibriosis is the most prevalent bacterial disease in cod farming and is the main cause for the increased use of antibiotics in cod farming. The choice between water based and oil based vaccines is an adjustment between cost, effect and side effects. Vaccination of salmon with oil based vaccines has shown an increased risk of side effects, but gives at the same time good and long lasting protection. This is necessary to avoid disease outbreak and following use of antibiotics in cod farming cod from Nordland Marin Yngel with an average weight of 50 gram were pit tagged and vaccinated with 4 different vaccines; 0.05 ml oil based vaccine from Intervet, 0.1 ml oil based vaccine from Intervet, 0.1 ml oil based vaccine from PHARMAQ and 0.1 ml water based vaccine from PHARMAQ. An unvaccinated control group was included. The fish was weighed and the length measured 1.5, 5 and 9 months after vaccination. At the same time the extent of side effects was scored. There was no difference in growth between the 5 groups, including the control group, 9 months after vaccination. Fish vaccinated with water based vaccine did not have more side effects than the unvaccinated control fish. It was significant more adhesions in the abdominal cavity in fish vaccinated with oil based vaccines compared to the water based vaccine. The difference between the oil based vaccines was first of all related to the location of adhesions. For both the vaccines from Intervet, more adhesions were found in the anterior part of the abdominal cavity compared to the fish vaccinated with vaccines from PHARMAQ.

9 Low space demanding packaging method (Super MAP) prolongs shelf life of farmed cod fillets. Anlaug Ådland Hansen 1, Thomas Eie, Turid Mørkøre 2 1 Nofima Mat 2 Nofima Marin Materials and methods Farmed Atlantic cod (Gadhus morhua) reared at Nofima Marin research station (Averøy, Norway) were used in this investigation. The mean body weight was 2.5 kg. The seawater temperature at slaughtering was 13 C.The cod were chilled in RSW. Gutting and filleting (pre-rigor) were done immediately after slaughtering. Pieces of fillets were refrigerated stored and packaged pre-rigor. The packaging methods being used: 1) Standard MAP with high gas volume (gas/product ratio of 3.9/1.0) 2) Super MAP, with a CO 2 -emitter and low gas volume (gas/product ratio of 1.3/1.0 A CO 2 -emitter is a thin pad continuously releasing CO 2 inside package, which maintain a constant CO 2 pressure and bacterial inhibition. 3) Vacuum The pre-mixed packaging gas used for the two MAP methods was 60 % CO 2 and 40 % O 2. Results Quality changes during three weeks of refrigerated storage (1.3 C) were studied. Sensory scores of the negative properties sour-, sulphur- and pungent odor were significantly higher for vacuum packed cod compared to the two MA-packaging methods measured 14 days after slaughtering. No differences in sensory scores were observed between the two methods of MAP, and shelf life of these samples was days. High level of oxygen in the gas mixture prevented formation of trimethyl amine (TMA), whereas the TMA content increased significantly after 10 days storage in vacuum. Bacterial growth was inhibited by MAP and resulted at the end of the storage period, in dominance of Carnobacterium, and some Photobacterium. Sulphide producing bacteria (SPB) were inhibited by the CO 2 -gas. In MA-packages with high O 2 -levels the Photobacterium was inhibited. Conclusions The shelf life using MAP is almost doubled compared to vacuum packaging (equal for standard MAP and Super MAP). Super MAP almost halves the required package volume compared to standard MAP. Therefore Super MAP is a promising packaging method for the farmed cod industry.

10 Continuous light versus photoperiod: effects on eye size and deformities in larval and juvenile cod

11 Natural zooplankton -live feed of the future?

12 Sats på torsk! Nettverksmøte 2010 Sats på Torsk! konferansen er en årlig nasjonal møteplass for oppdrettstorsk, og har som intensjon å være oppdrettsnæringens, forskningsmiljøene og forvaltningen i Norge sin viktigste arena for faglig oppdatering, diskusjoner og nettverksbygging innen oppdrettstorsk. Konferansen er et samarbeid mellom Norsk Sjømatsenter og NCE Aquaculture Konferansen er støttet av: Innovasjon Norge, Fiskeri og Havbruksnæringens Forskningsfond, Norges forskningsråd Konferansens festmiddag: Onsdag kl. 20:00 Radisson Blu Hotel