Studies On Lipid Nutrition And The Expression Of Genes For Desaturase And Elongase Enzymes In Snakehead, Channa Striata (Bloch, 1973) Fingerlings
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Date
2011-07
Authors
Paiko, Mohammed Aliyu
Journal Title
Journal ISSN
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Publisher
Universiti Sains Malaysia
Abstract
This study examined lipid nutrition in C. striata fingerlings, through a series
of experimental feeding trials, including; the evaluation of lipid/protein ratio and
fatty acid (FA) requirements, as well as the screening of some of its tissues for the
expression of genes for fatty acyl desaturase (FAD) and fatty acyl elongase (FAE)
enzymes. These preliminary studies provided some insight about lipid metabolism in
the species; suggesting that snakehead fingerling requires 65/450 g kgô€€€1 lipid/protein
ratio, provided in a diet supplying a GE content of 18.5 kJ gô€€€1. The tissues screened
revealed that FAD and FAE genes are all expressed more in the liver and brain than
in the muscle, kidney, skin, intestine, testis and ovary. In further experimental trials,
dietary FO in feeds for the species was incrementally substituted with crude palm
oil (CPO) and palm fatty acid distillate (PFAD), both of which are relatively cheaper
than FO and abundant in Malaysia and Indonesia. Results revealed that growth
performance and feed efficiency improved (P<0.05) with increasing vegetable oils
(VO) in the diet up till 50% of FO was substituted, above which additional dietary VO
resulted in non-significant decline. The expression of genes in response to dietary VO
revealed that FAE was up-regulated in the 50CPO and 50PFAD groups compared to
the control, whereas FAD was only up-regulated in the 50CPO group accordingly. The
whole body composition of lipids, FA and amino acids (AA) was compared between
reared and wild C. striata juvenile, the result revealing no much difference in the
contents of arachidonic acid (ArA), glycine, aspartic and glutamic acids, as well as
all other essential AA respectively.
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Keywords
lipid nutrition in C. striata fingerlings , through a series of experimental feeding trials