Page 44

Feed – research 140

Retention (% intake) Retention (% intake)

M-fish V-fish

a

120 100 140 80 120 60 100 40 80 20 60 0 40

b* a

a*

b

b

a b*

a

b* a

b

b

Protein

Lipid

Energy

a*

Protein

b*

Lipid

Energy

Challenge phase

Marine phase

20

M-fish V-fish

a

Fig. 3

0

‘programmed’ fish, and with retentions of theEnergy Fig. 3. Nutrient and energy retentions duringthethe marine challenge phases. Data are Protein Lipid important omega-3 fatty acids, EPA and DHA, being particularly Challenge enhanced. phase While these results are highly positive and means ± SEM (n = 3) based on nutritional history during the stimulus phase (M-fish or Vencouraging, there is still a need for further re-

include adaptive changes inProtein gene expression such as epigenetic (non-geLipid Energy netic) phenomenon such as DNA methylation, histone modification, or microRNA, preferential clonal selection of adapted cells or programmed Marine phase differential proliferation of tissue cell types. In the present study, liver gene expression was examined using microarray technology in fish at the end of the challenge phase. Preliminary data have indicated that V-fish showed up-regulation of pathways of intermediary metabolism, such as oxidative phosphorylation, pyruvate metabolism, TCA cycle, glycolysis/gluconeogenesis and amino acid metabolism, as well as key pathways of lipid metabolism, including polyunsaturated fatty acid biosynthesis and elongation, antioxidant defence and immune system. Epigenetic analysis is currently in progress and will hopefully provide further insight into the biochemical and molecular mechanisms of nutritional programming. Overall, the present study confirmed that nutritional programming can operate in Atlantic salmon and lead to metabolic adaptations that 800 the capability of the fish to utilise alternative, non-marine may enhance a dietary ingredients. These adaptations led to improved nutrient and energy retentions in

search into the concept of nutritional program-

Fig. 3. Nutrient and energy retentions during marine and challenge Data are Other ming the in farmed fish. For instance, other results phases. fish). Superscripts denote significant differences (p < 0.05) between dietary history and from within the ARRAINA project have indicated

Retention (% intake) Retention (% intake)

results have means ± SEM (n = 3) based on nutritional history during the stimulus phase (M-fish or Vindicated asterisks denote significant differences between feeding phases. that the fish). Superscripts denote significant differences (p < 0.05) between dietaryinitial history and stimulus asterisks denote significant differences between feeding phases. phase can be much shorter 600 800 400

a

600 200

200 -200 0 -200

a

b

b

EPA

V-fish

M-fish V-fish

b

a

400 0

that the initial stimulus phase can be much shorter than that used in the present study, perhaps only three to six days. This would minimise the potential for the stimulus phase itself to induce any phenotypic changes in programmed fish, and could facilitate the application of the nutritional programming concept in commercial farming operations. Douglas R Tocher, Michael Clarkson and John F Taylor, Institute of Aquaculture, University of M-fish Stirling. FF

DHA

Above: Protein, lipid

and energy retentions were all significantly higher in V-fish during the challenge phase. Left: Retention of DHA was far greater than EPA as expected.

b

EPA DHA Fig. 4. EPA and DHA retentions during the challenge period. Data are means ± SEM (n = 3) 44 www.fishfarmer-magazine.com

based on nutritional history during the stimulus phase (M-fish or V-fish). Superscripts Feed - Douglas Tocher.indd 44

16/01/2017 11:47:13

Profile for Fish Farmer Magazine

Fish Farmer Magazine january 2017  

Serving Worldwide Aquaculture Since 1977

Fish Farmer Magazine january 2017  

Serving Worldwide Aquaculture Since 1977

Advertisement