Skov, Peter V. (2018) Boldness in fishes: A selection tool for aquaculture or a personality type with no apparent return? [Robusthed hos fisk: Et selektionsredskab i akvakultur eller karaktertræk med begrænset profit?] Keynote presentation at: University of Stirling, School of Aquaculture seminar series., University of Stirling, 8 February 2018.
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Summary
Behavioural and physiological results demonstrated that different emergence fractions of rainbow trout fry differed in certain characteristics. Early emerging fractions were more bold, they displayed more exploratory behaviour and recovered faster from startling compared to intermediate and late emerging fish. There were no differences in metabolic parameters of different emergence fractions, however, early emerging fractions had a smaller oxygen debt following chasing, and repaid it quicker. Early emerging fractions had a smaller cortisol response following a low water level challenge, but mobilization of glycogen stores did not differ between fractions. Early emerging fractions had a higher rate of weight loss in the face of starvation, probably linked to higher routine activity levels. The intermediate group was most starvation tolerant, and gained weight faster during refeeding. Co-habitation of different emerging fractions did not reveal a competitive advantage of early emerging fish under a restrictive feeding regime – again, the intermediate group outperformed the others. Overall, the intermediate group appears to have the best characteristics for production in an ‘optimal’ environment. Some fish farmers are currently using the early emerging fraction to put in sea cages. Though, the production costs are slightly higher, this is more than met and losses reduced!
Summary translation
Adfærdsmæssige og fysiologiske undersøgelser viste, at forskellige swim-up fraktioner af regnbueørred yngel adskilte sig i visse karakter træk. Tidlig swim-up fraktioner var mere udfarende, idet de udviste mere undersøgende adfærd og kom sig hurtigere efter påført stress-test sammenlignet med mellem og sen swim-up fisk. Der var imidlertid ingen forskelle i metabolske parametre i de forskellige fraktioner; dog havde den tidlige fraktion en lavere ilt-gæld efter at være blevet jaget rundt, og tilbagebetalte hurtigere. De tidlige fraktioner viste en lavere kortisol respons efter lav vandstand-stress, men der var ingen forskel i mobiliseringen af glykogen depoterne mellem fraktionerne. De tidlige fraktioner havde et højere vægttab efter sult, sandsynligvis knyttet til højere rutine aktivitets niveauer. Mellem-gruppen var mest sult tolerant, og tog hurtigere på i vægt efter genoptag af fodring. Restriktiv fodring syntes ikke at påvirke territorie adfærd – dog med en vis dominans af mellemgruppen. Generelt syntes mellemgruppen at have de bedste karaktertræk for produktion i et optimalt miljø. Nogle dambrugere udsætter de tidlige fraktioner i netbure. Selvom produktions omkostningerne er lidt højere udlignes dette fuldt ud for den samlede produktion.
| EPrint Type: | Conference paper, poster, etc. |
|---|---|
| Type of presentation: | Keynote presentation |
| Keywords: | Rainbow trout, bold, metabolic, emergence, |
| Subjects: | Animal husbandry > Health and welfare |
| Research affiliation: | Denmark > Organic RDD 2 > RobustFish |
| Deposited By: | Jokumsen, Senior Advisory Scientist Alfred |
| ID Code: | 32724 |
| Deposited On: | 05 Apr 2018 10:03 |
| Last Modified: | 05 Apr 2018 10:03 |
| Document Language: | English |
| Status: | Published |
| Refereed: | Not peer-reviewed |
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