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Áhrif fiskpróteinmeltu á þroska þorsklirfa / The effect of fish protein hydrolysate on the development of cod larvae

Author(s):

Hólmfríður Sveinsdóttir, Jónína Jóhannsdóttir, Rannveig Björnsdóttir, Oddur Vilhelmsson, Hugrún Lísa Heimisdóttir, Patricia Hamaguchi, Annabelle Vrac, Gunnlaugur Sighvatsson, Steinar Svavarsson, Arnljótur Bjarki Bergsson, Agnar Steinarsson

Funded by:

AVS

Áhrif fiskpróteinmeltu á þroska þorsklirfa / The effect of fish protein hydrolysate on the development of cod larvae

Eitt helsta vandamálið við eldi á þorski eru mikil afföll á fyrstu stigum þroskunar og gæði seiða. Markmið þessa verkefnis var að fá heilsteyptari mynd af áhrifum auðgunar fæðudýra með ufsapróteinmeltu á lífefnaferla í snemmþroska þorsk með því að beita myndgreiningaraðferðum og próteinmengjagreiningu. Niðurstöður benda til töluverðrar andoxunarvirkni ufsapróteinmeltu auk nokkurrar áhrifa á bólguvirkni. Afkoma lirfa í eldistilraun var frekar lág þó svo að vaxtarhraði væri alveg viðunandi og lítið væri um alvarlega útlitsgalla. Meðhöndlun með ufsapróteinmeltu reyndist ekki hafa áhrif á afkomu eða galla lirfa en vísbendingar voru um örvun á framleiðslu IgM og lysozyme í meltingarvegi og á yfirborði lirfa. Próteinmengjagreiningar sýndu að meðhöndlun hafði áhrif á tjáningu frumugrindapróteina, próteina sem taka þátt í streitu auk efnaskiptaensímsins ATP‐synthasa. Niðurstöður benda til að notkun ufsapróteinmeltu geti bætt og jafnað gæði seiða ef gæði eggja er ábótavant en þegar notuð eru egg af góðum þá hafi meðhöndlun ekki áhrif.

High larval mortalities and anatomical deformities are among the major obstacles restricting the development of Atlantic cod aquaculture. The present project was aimed at studying the effects of a pollock hydrolysate supplementation during early developmental stages of cod on growth, development and survival. Furthermore, protein expression was evaluated as well as the distribution and intensities of selected parameters of the unspecific immune system. The hydrolysate was found to display antioxidant activity and can be regarded as a feed supplement to the live prey items. The survival from larvae to juvenile in the experiment was relatively poor, with satisfactory larval growth and low incidence of severe deformities. Offering hydrlysate enhanced live prey to larvae did not affect larval survival or development. Treatment resulted in stimulated IgM and lysozyme production. Proteome analysis showed that treatment with fish hydrolysates has an effect on the expression of structural, stress and metabolic proteins. Overall, the results indicate that fortification of the live prey with pollock hydrolysate can result in improved or more even larval quality following poor egg quality, however, with no effects if eggs are of better quality.  

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