Quantitative genetics of traits related to disease resistance and effects of vaccination in Atlantic salmon (Salmo salar)
Disease resistance is of major importance to the fish farming industry as disease outbreaks have negative effects on the industry’s economy, its reputation and on fish welfare. Today, almost all fish in the Norwegian salmon industry are vaccinated against a number of diseases, while selection for in...
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Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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Norwegian University of Life Sciences, Ås
2011
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Online Access: | http://hdl.handle.net/11250/2434182 |
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Open archive Norwegian University of Life Sciences: Brage NMBU |
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ftunivmob |
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English |
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VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 |
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VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 Drangsholt, Tale Marie Karlsson Quantitative genetics of traits related to disease resistance and effects of vaccination in Atlantic salmon (Salmo salar) |
topic_facet |
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 |
description |
Disease resistance is of major importance to the fish farming industry as disease outbreaks have negative effects on the industry’s economy, its reputation and on fish welfare. Today, almost all fish in the Norwegian salmon industry are vaccinated against a number of diseases, while selection for increased resistance to specific diseases is based on survival of unvaccinated fish in challenge tests. The main aim of this doctorial thesis was to obtain a better understanding of how to select for increased resistance to furunculosis in Atlantic salmon and how this relates to side effects of vaccination, taking into account that most fish in the industry are currently vaccinated. Resistance to furunculosis (survival) was recorded by challenge testing fish from 150 families (unvaccinated and vaccinated fish). Vaccine-induced side effects (adhesions of internal organs and melanin deposits) were recorded on samples of the 150 families at three points in time: after three months in freshwater (high temperature), and six and 12 months after sea transfer. The first objective was to estimate the magnitude of the genetic (co)variation in survival of unvaccinated and vaccinated Atlantic salmon challenged with A. salmonicida, the bacteria causing furunculosis. The results showed a low genetic correlation between resistance to furunculosis in unvaccinated and vaccinated fish. The second objective was to estimate the magnitude of genetic variation of the negative side effects of vaccination. Intermediate heritabilities were obtained for adhesions and melanin deposits. However, the results also showed that an alternative vaccine reduced the side effects compared to the standard vaccine. The third objective was to estimate the magnitude of the genetic correlation between disease resistance, side effects of vaccination, and harvest body weight. These traits were not genetically correlated; though a possible exception is harvest body weight and survival of vaccinated fish, where a weak and unfavorable correlation was reported. Today’s breeding strategy of testing unvaccinated fish is optimal if the long term goal is a reduced need for vaccination. Selection based on vaccinated fish is likely to be the most effective short term strategy, as all fish in the industry today are vaccinated. However, this strategy is not very relevant for furunculosis as the vaccine is highly effective. Vaccine-induced side effects (adhesions and melanin deposits) could be reduced through selective breeding, but it is likely to be more appropriate to focus on other measures such as vaccine development. Selection for increased disease resistance, vaccine-induced side effects, or harvest body weight are not expected to lead to unfavorable correlated responses in any of these traits, with the possible exception of survival of vaccinated fish and harvest body weight. Forbedret sykdomsresistens hos Atlantisk laks er viktig for oppdrettsnæringen ettersom sykdomsutbrudd har negativ påvirking på næringens økonomi og omdømme, og på fiskens velferd. I dag vaksineres det aller meste av fisken mot en rekke sykdommer. Samtidig pågår det et avlsarbeid for økt sykdomsresistens basert på resultater fra smittetester med uvaksinert fisk. Hovedmålet med dette doktorgradsarbeidet var å få bedre forståelse for hvordan man bør selektere for økt resistens mot bakteriesykdommen furunkulose (forårsaket av bakterien A. salmonicida), og hvordan dette er relatert til bivirkninger av vaksinering. Resistens ble målt som overleving i smittetester hos fisk fra 150 familier. Vaksinebivirkninger, sammenvoksinger av organ i bukhulen og melaninflekker på organ og bukvegg, ble målt på et tilfeldig utvalg av fisk fra de 150 familiene på tre ulike tidspunkt: Etter tre måneder i ferskvann (høy temperatur) og seks og tolv måneder etter sjøutsett. I smittetest med furunkulose ble det funne høyere genetisk variasjon for uvaksinert enn vaksinert fisk og en relativ lav genetisk korrelasjon mellom furunkuloseresistens i uvaksinert og vaksinert fisk. For sammenvoksinger og melaninflekker ble det funnet middels store arvegrader. En alternativ vaksine gav reduserte vaksinebivirkninger sammenlignet med standardvaksinen. Egenskapene sykdomsresistens, vaksinebivirkninger og slaktevekt ble funnet å ikke være genetisk korrelert, med et mulig unntak mellom slaktevekt og overlevelse av vaksinert fisk i smittetest hvor det ble funnet en svak, ugunstig korrelasjon. Dagens avlsstrategi basert på smittetester med uvaksinert fisk er optimal hvis det langsiktige avlsmålet er å redusere bruken av vaksinering. Seleksjon basert på vaksinert fisk er likevel den optimale strategien på kort sikt ettersom all fisk i næringen vaksineres, men en liten aktuell strategi for furunkulose ettersom dagens vaksine mot furunkulose er svært effektiv. Vaksinebivirkninger (sammenvoksninger og melaninflekker) kan reduseres gjennom alvsarbeid, men det er mest sannsynlig mer hensiktsmessig å fokusere på andre tiltak som for eksempel vaksineutvikling. Seleksjon for økt sykdomsresistens og slaktevekt og reduserte vaksinebivirkninger forventes ikke å gi ugunstige korrelerte responser i noen av de andre egenskapene, men overlevelse av vaksinert fisk og slaktevekt kan være et unntak. PHARMAQ AS The Fishery and Aquaculture Industry Research Fund |
author2 |
Gjerde, Bjarne Ødegård, Jørgen |
format |
Doctoral or Postdoctoral Thesis |
author |
Drangsholt, Tale Marie Karlsson |
author_facet |
Drangsholt, Tale Marie Karlsson |
author_sort |
Drangsholt, Tale Marie Karlsson |
title |
Quantitative genetics of traits related to disease resistance and effects of vaccination in Atlantic salmon (Salmo salar) |
title_short |
Quantitative genetics of traits related to disease resistance and effects of vaccination in Atlantic salmon (Salmo salar) |
title_full |
Quantitative genetics of traits related to disease resistance and effects of vaccination in Atlantic salmon (Salmo salar) |
title_fullStr |
Quantitative genetics of traits related to disease resistance and effects of vaccination in Atlantic salmon (Salmo salar) |
title_full_unstemmed |
Quantitative genetics of traits related to disease resistance and effects of vaccination in Atlantic salmon (Salmo salar) |
title_sort |
quantitative genetics of traits related to disease resistance and effects of vaccination in atlantic salmon (salmo salar) |
publisher |
Norwegian University of Life Sciences, Ås |
publishDate |
2011 |
url |
http://hdl.handle.net/11250/2434182 |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_source |
1 b. (flere pag.) |
op_relation |
PhD Thesis;2011:39 Norges Forskningsråd: 179009/S40 urn:isbn:978-82-575-1002-2 urn:issn:1503-1667 http://hdl.handle.net/11250/2434182 |
op_rights |
Attribution-NonCommercial-NoDerivatives 4.0 Internasjonal http://creativecommons.org/licenses/by-nc-nd/4.0/deed.no |
op_rightsnorm |
CC-BY-NC-ND |
_version_ |
1766363099297742848 |
spelling |
ftunivmob:oai:nmbu.brage.unit.no:11250/2434182 2023-05-15T15:32:36+02:00 Quantitative genetics of traits related to disease resistance and effects of vaccination in Atlantic salmon (Salmo salar) Kvantitativ genetikk for egenskaper relatert til sykdomsresistens og effekter av vaksinering i Atlantisk laks (Salmo salar) Drangsholt, Tale Marie Karlsson Gjerde, Bjarne Ødegård, Jørgen 2011 application/pdf http://hdl.handle.net/11250/2434182 eng eng Norwegian University of Life Sciences, Ås PhD Thesis;2011:39 Norges Forskningsråd: 179009/S40 urn:isbn:978-82-575-1002-2 urn:issn:1503-1667 http://hdl.handle.net/11250/2434182 Attribution-NonCommercial-NoDerivatives 4.0 Internasjonal http://creativecommons.org/licenses/by-nc-nd/4.0/deed.no CC-BY-NC-ND 1 b. (flere pag.) VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 Doctoral thesis 2011 ftunivmob 2021-09-23T20:16:12Z Disease resistance is of major importance to the fish farming industry as disease outbreaks have negative effects on the industry’s economy, its reputation and on fish welfare. Today, almost all fish in the Norwegian salmon industry are vaccinated against a number of diseases, while selection for increased resistance to specific diseases is based on survival of unvaccinated fish in challenge tests. The main aim of this doctorial thesis was to obtain a better understanding of how to select for increased resistance to furunculosis in Atlantic salmon and how this relates to side effects of vaccination, taking into account that most fish in the industry are currently vaccinated. Resistance to furunculosis (survival) was recorded by challenge testing fish from 150 families (unvaccinated and vaccinated fish). Vaccine-induced side effects (adhesions of internal organs and melanin deposits) were recorded on samples of the 150 families at three points in time: after three months in freshwater (high temperature), and six and 12 months after sea transfer. The first objective was to estimate the magnitude of the genetic (co)variation in survival of unvaccinated and vaccinated Atlantic salmon challenged with A. salmonicida, the bacteria causing furunculosis. The results showed a low genetic correlation between resistance to furunculosis in unvaccinated and vaccinated fish. The second objective was to estimate the magnitude of genetic variation of the negative side effects of vaccination. Intermediate heritabilities were obtained for adhesions and melanin deposits. However, the results also showed that an alternative vaccine reduced the side effects compared to the standard vaccine. The third objective was to estimate the magnitude of the genetic correlation between disease resistance, side effects of vaccination, and harvest body weight. These traits were not genetically correlated; though a possible exception is harvest body weight and survival of vaccinated fish, where a weak and unfavorable correlation was reported. Today’s breeding strategy of testing unvaccinated fish is optimal if the long term goal is a reduced need for vaccination. Selection based on vaccinated fish is likely to be the most effective short term strategy, as all fish in the industry today are vaccinated. However, this strategy is not very relevant for furunculosis as the vaccine is highly effective. Vaccine-induced side effects (adhesions and melanin deposits) could be reduced through selective breeding, but it is likely to be more appropriate to focus on other measures such as vaccine development. Selection for increased disease resistance, vaccine-induced side effects, or harvest body weight are not expected to lead to unfavorable correlated responses in any of these traits, with the possible exception of survival of vaccinated fish and harvest body weight. Forbedret sykdomsresistens hos Atlantisk laks er viktig for oppdrettsnæringen ettersom sykdomsutbrudd har negativ påvirking på næringens økonomi og omdømme, og på fiskens velferd. I dag vaksineres det aller meste av fisken mot en rekke sykdommer. Samtidig pågår det et avlsarbeid for økt sykdomsresistens basert på resultater fra smittetester med uvaksinert fisk. Hovedmålet med dette doktorgradsarbeidet var å få bedre forståelse for hvordan man bør selektere for økt resistens mot bakteriesykdommen furunkulose (forårsaket av bakterien A. salmonicida), og hvordan dette er relatert til bivirkninger av vaksinering. Resistens ble målt som overleving i smittetester hos fisk fra 150 familier. Vaksinebivirkninger, sammenvoksinger av organ i bukhulen og melaninflekker på organ og bukvegg, ble målt på et tilfeldig utvalg av fisk fra de 150 familiene på tre ulike tidspunkt: Etter tre måneder i ferskvann (høy temperatur) og seks og tolv måneder etter sjøutsett. I smittetest med furunkulose ble det funne høyere genetisk variasjon for uvaksinert enn vaksinert fisk og en relativ lav genetisk korrelasjon mellom furunkuloseresistens i uvaksinert og vaksinert fisk. For sammenvoksinger og melaninflekker ble det funnet middels store arvegrader. En alternativ vaksine gav reduserte vaksinebivirkninger sammenlignet med standardvaksinen. Egenskapene sykdomsresistens, vaksinebivirkninger og slaktevekt ble funnet å ikke være genetisk korrelert, med et mulig unntak mellom slaktevekt og overlevelse av vaksinert fisk i smittetest hvor det ble funnet en svak, ugunstig korrelasjon. Dagens avlsstrategi basert på smittetester med uvaksinert fisk er optimal hvis det langsiktige avlsmålet er å redusere bruken av vaksinering. Seleksjon basert på vaksinert fisk er likevel den optimale strategien på kort sikt ettersom all fisk i næringen vaksineres, men en liten aktuell strategi for furunkulose ettersom dagens vaksine mot furunkulose er svært effektiv. Vaksinebivirkninger (sammenvoksninger og melaninflekker) kan reduseres gjennom alvsarbeid, men det er mest sannsynlig mer hensiktsmessig å fokusere på andre tiltak som for eksempel vaksineutvikling. Seleksjon for økt sykdomsresistens og slaktevekt og reduserte vaksinebivirkninger forventes ikke å gi ugunstige korrelerte responser i noen av de andre egenskapene, men overlevelse av vaksinert fisk og slaktevekt kan være et unntak. PHARMAQ AS The Fishery and Aquaculture Industry Research Fund Doctoral or Postdoctoral Thesis Atlantic salmon Salmo salar Open archive Norwegian University of Life Sciences: Brage NMBU |