Citation
Lim, Keng Chin
(2020)
Dietary astaxanthin for growth and health enhancement of Asian seabass, Lates calcarifer (Bloch, 1790).
Doctoral thesis, Universiti Putra Malaysia.
Abstract
Astaxanthin is renowned for its commercial application in numerous industries
comprising cosmetic, food, aquaculture, nutraceutical, and pharmaceutical. The
freshwater green microalga Haematococcus pluvialis is the richest bio-resource
of natural astaxanthin. The supreme antioxidant property of astaxanthin reveals
its tremendous potential to offer manifold health benefits amongst aquatic
animals. Like many cultured fish species, the intensive farming of Asian
seabass Lates calcarifer under stressful circumstances has posed several
major problems, including sluggish growth, poor survival, and susceptibility to
pathogenic diseases. This study investigated the effects of supplementation
with astaxanthin (dose-response manner) on growth performance, survival,
hemato-biochemical indices, innate immunity, histopathological responses, and
disease resistance of the Asian seabass.
A two-stage process was employed for the astaxanthin-rich biomass production
of H. pluvialis in the airlift annular photobioreactor. Astaxanthin content was
quantitatively determined via the high-performance liquid chromatography
(HPLC) analytical method. Four experimental diets, including a control diet
(CD), and diets containing various dietary levels of astaxanthin (AX50, 50 mg
kg-1 diet; AX100, 100 mg kg-1 diet; and AX150, 150 mg kg-1 diet) supplemented
with astaxanthin-containing lyophilized H. pluvialis biomass (~37.94 ± 0.41 mg
astaxanthin g-1 dry weight) were produced for different feeding trials.
Findings from the first trial revealed that fish exhibited significant linear
increments (P < 0.05) in specific growth rate, weight gain, feed utilization
efficiency, survival, and serum growth hormone (GH) availability when fed diets
with escalating levels of astaxanthin during distinct feeding phases (short-term,
medium-term and long-term). Significant positive correlations (P < 0.05) were
noted between serum GH level and SGR of fish from all groups following three consecutive feeding phases, denoting a robust cause-and-effect relationship.
Circulating serum GH concentration was recognized as a sensitive biomarker
of growth performance in the Asian seabass.
Moreover, in the second trial, fish displayed profound enhancements (P < 0.05)
in hematological indices (white blood cell (WBC) count, red blood cell (RBC)
count, hemoglobin, and hematocrit) when fed diets with elevated doses of
astaxanthin over different phases of feeding (short-term, medium-term and
long-term). Serum concentrations of alanine aminotransferase (ALT), aspartate
aminotransferase (AST), glucose, cholesterol, triglyceride, and cortisol in the
treated fish reduced significantly (P < 0.05) with increasing dietary inclusion
levels throughout the specified feeding phases. Correspondingly, the
supplemented fish registered remarkably higher (P < 0.05) serum total protein
content. Immunological parameters (lysozyme activity, phagocytic activity,
respiratory burst activity, and total serum immunoglobulin) of fish were
significantly stimulated (P < 0.05) in response to dietary intervention with
astaxanthin.
Experimental infection with Vibrio alginolyticus unveiled that supplemented fish
demonstrated significant improvements (P < 0.05) of hematological parameters
(WBC and RBC counts, and hemoglobin and hematocrit levels) when fed diets
with elevating supplemental doses of astaxanthin through distinct post-infection
periods (0-, 7-, and 14-day). Furthermore, the administration of dietary
astaxanthin at escalating levels markedly enhanced (P < 0.05) the serum
biochemical profile (AST, ALT, glucose, cortisol, cholesterol, and triglyceride
contents) of challenged fish, resulting in better welfare. Significantly higher (P <
0.05) contents of serum total protein were discernible in supplemented fish, as
opposed to the control. Additionally, non-specific defense mechanisms
(lysozyme activity, phagocytic activity, respiratory burst activity, and total serum
immunoglobulin) of challenged fish were pronouncedly elicited (P < 0.05)
following the ingestion of astaxanthin. Histopathological alterations in target
organs (liver, kidney, and spleen) of challenged fish were observed to be
significantly reduced progressively (P < 0.05) with increasing dietary intake of
astaxanthin. Besides, supplementation with dietary astaxanthin significantly
augmented (P < 0.05) the post-challenge survival rate of fish.
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Additional Metadata
Item Type: |
Thesis
(Doctoral)
|
Subject: |
Giant perch |
Subject: |
Fishes - Nutrition |
Subject: |
Antioxidants - Therapeutic use |
Call Number: |
FP 2021 37 |
Chairman Supervisor: |
Professor Fatimah Md. Yusoff, PhD |
Divisions: |
Faculty of Agriculture |
Depositing User: |
Ms. Nur Faseha Mohd Kadim
|
Date Deposited: |
26 Aug 2022 07:27 |
Last Modified: |
26 Aug 2022 07:27 |
URI: |
http://psasir.upm.edu.my/id/eprint/98379 |
Statistic Details: |
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