Effects Of Dietary Astaxanthin Research Articles

Effects of dietary astaxanthin on growth performance, immunity, and tissue composition in largemouth bass, Micropterus salmoides

This study examined the effects of feeding largemouth bass (Micropterus salmoides) with diets containing different doses of astaxanthin (0, 50, 100, 150, and 200 mg/kg) for 8 weeks. The results showed that the values of weight gain significantly increased from 620.32 ± 50.38% to 826.14 ± 33.49% as dietary astaxanthin levels increased from 0 mg/kg to 100 mg/kg. When the astaxanthin level exceeded 150mg/kg, the weight gain rate showed a downward trend, but there was no significant difference among of the 100, 150 and 200 mg/kg groups. The feed conversion ratio (FCR) and protein efficiency ratio (PER) were also improved by adding astaxanthin to diets (P < 0.05). Meanwhile, adding astaxanthin to the feed increased the length and thickness of intestinal villus and muscle layer thickness (P < 0.05). The astaxanthin supplementation increased the expression of the NF-E2-related factor (Nrf2) gene and reduced malondialdehyde (MDA) content and the expression of apoptosis genes Caspase-9 and Caspase-3 (P < 0.05), indicating that it has a good antioxidant ability. Furthermore, adding astaxanthin increased the content of non-specific immune markers and decreased the expression levels of the inflammatory factors interleukin-15 (IL-15) and tumor necrosis factor-α (TNF-α). Moreover, fish fed diets with astaxanthin exhibited lower blood cortisol levels (P < 0.05). The proportions of C20:4n6 (ARA) and C20:5n3 (EPA) in the liver decreased with increasing dietary astaxanthin levels. Based on WGR and SGR values, the optimal addition level of astaxanthin in largemouth bass feed is 134.8 mg/kg ~ 135.75 mg/kg. In summary, the appropriate dietary astaxanthin enhanced the antioxidant capacity and immune response of largemouth bass and had a positive effect on its intestinal health.

Effects of dietary astaxanthin on growth performance, muscle composition, non-specific immunity, gene expression, and ammonia resistance of juvenile ivory shell (Babylonia areolate)

Astaxanthin is one of the important immunopotentators in aquaculture. However, little is known about the physiological changes and stress resistance effects of astaxanthin in marine gastropods. In this study, the effects of different astaxanthin concentrations (0, 25, 50, 75, and 100 mg/kg) on the growth, muscle composition, immune function, and resistance to ammonia stress in Babylonia areolata were investigated after three months of rearing. With the increase in astaxanthin content, the weight gain rate (WGR), specific growth rate (SGR), and survival rate (SR) of B. areolata showed an increasing trend. The 75–100 mg/kg group was significantly higher than the control group (0 mg/kg). There was no significant difference in the flesh shell ratio (FSR), viscerosomatic index (VSI), and soft tissue index (STI) of the experimental groups. Astaxanthin (75 mg/kg) significantly increased muscle crude protein content and increased hepatopancreas alkaline phosphatase (AKP), superoxide dismutase (SOD), and catalase (CAT) activity. Astaxanthin (75–100 mg/kg) significantly increased the total antioxidant capacity (T-AOC) and acid phosphatase (ACP) of the hepatopancreas and decreased the malondialdehyde (MDA) content of B. areolata. Astaxanthin significantly induced the expression levels of functional genes, such as SOD, Cu/ZnSOD, ferritin, ACP, and CYC in hepatopancreas and increased the survival rate of B. areolata under ammonia stress. The addition of 75–100 mg/kg astaxanthin to the feed improved the growth performance, muscle composition, immune function, and resistance to ammonia stress of B. areolata.

Effects of Natural and Synthetic Astaxanthin on Growth, Body Color, and Transcriptome and Metabolome Profiles in the Leopard Coralgrouper (Plectropomus leopardus).

Natural and synthetic astaxanthin can promote pigmentation in fish. In this study, the effects of dietary astaxanthin on growth and pigmentation were evaluated in leopard coralgrouper (Plectropomus leopardus). Fish were assigned to three groups: 0% astaxanthin (C), 0.02% natural astaxanthin (HP), and 0.02% synthetic astaxanthin (AS). Brightness (L*) was not influenced by astaxanthin. However, redness (a*) and yellowness (b*) were significantly higher for fish fed astaxanthin-containing diets than fish fed control diets and were significantly higher in the HP group than in the AS group. In a transcriptome analysis, 466, 33, and 32 differentially expressed genes (DEGs) were identified between C and HP, C and AS, and AS and HP, including various pigmentation-related genes. DEGs were enriched for carotenoid deposition and other pathways related to skin color. A metabolome analysis revealed 377, 249, and 179 differential metabolites (DMs) between C and HP, C and AS, and AS and HP, respectively. In conclusion, natural astaxanthin has a better coloration effect on P. leopardus, which is more suitable as a red colorant in aquaculture. These results improve our understanding of the effects of natural and synthetic astaxanthin on red color formation in fish.

Dietary astaxanthin mitigated paraquat‐induced oxidative stress in rainbow trout ( Oncorhynchus mykiss ) fillet

In this study, the effects of dietary astaxanthin (Lucantin Pink®) at 0.5 and 2 g kg−1 incorporated in the control diet were investigated on growth performance, biochemical parameters, including protein and lipid oxidation levels, peroxide value, pH level and water content as well as gene expression level related to catalase, glutathione peroxidase, glutathione S-transferase and superoxide dismutase in rainbow trout (Oncorhynchus mykiss) fillet. The fish (mean weight 20.69 g) were randomly distributed among 12 tanks with 10 fish per tank and fed different diets for 60 days. On day 60, each group was divided into two subgroups. In one of the subgroups, fish were exposed to paraquat (PQ) challenge at a level of 4.82 mg/L for 96 h. The other subset was used as the negative control. The results indicated that the treated diets enhanced the growth performance compared with the control diet. The protein and lipid oxidation levels and peroxide value also decreased significantly with the enriched diets compared with the control group exposed to PQ. Conversely, no significant changes were noted in the pH level and water content following the challenge with PQ. Feeding fish astaxanthin and challenging them with PQ also up-regulated the expression of the mentioned antioxidant-relevant genes in rainbow trout fillet. Based on the results, it was concluded that commercial astaxanthin improved the growth performance and attenuated the oxidative stress induced by PQ in rainbow trout fillets by enhancing the functions of the antioxidant system.

Effects of dietary astaxanthin on the growth, innate immunity and antioxidant defence system of Paramisgurnus dabryanus

The effects of astaxanthin supplementationon the growth, innate immunity and antioxidant defence system of loach (Paramisgurnus dabryanus) were investigated in this study. A total of 450 fish (initial average weights of 3.00 ± 0.10 g) were fed five diets with graded levels of astaxanthin (0.00, 50.00, 100.00, 150.00 and 200.00 mg/kg) for 56 days. The results showed that astaxanthin supplementation significantly stimulated the growth (FBW, WG, FER, HSI), innate immunity (AKP activity in the hepatopancreas, intestinal tract, muscle and skin and LZM activity in the hepatopancreas, intestinal tract and skin), antioxidant ability (T-SOD, GSH-PX and CAT activities and T-AOC, GSH and MDA contents in the hepatopancreas, intestinal tract, muscle and skin) of loach. Moreover, dietary astaxanthin supplementation significantly up-regulated the relative mRNA levels of Nrf2 and Maf, and down-regulated the relative mRNA level of Keap1 in the hepatopancreas when the supplementation levels of astaxanthin were 50–200 mg/kg. In conclusion, the diets with 100–151.06 mg/kg astaxanthin supplementation were optimal for loach, which based on the growth, immunity and antioxidant-related indicators, and the astaxanthin supplementation regulated the antioxidant ability partially referring to Keap1-Nrf2 signallings.

Effects of dietary astaxanthin and vitamin E and their interactions on the growth performance, pigmentation, digestive enzyme activity of kuruma shrimp (Marsupenaeus japonicus )

A 56-day feeding trial was done to investigate the interactive effects of astaxanthin (Ax) and vitamin E (α-Toc) on the performance of kuruma shrimp (Marsupenaeus japonicus). A 2 × 3 factorial experiment was conducted with six experimental diets containing two levels of Ax (0 and 0.6 g/kg diet [Ax0 and Ax0.6]) and three levels of α-Toc (0, 0.2 and 1 g/kg diet [α-Toc0, α-Toc0.2 and α-Toc1]). The results indicated that growth performance was significantly (p < 0.05) increased in shrimp fed with the Ax0.6 × α-Toc0.2 diet. Interactive effects between Ax and α-Toc on the growth parameters were observed. Furthermore, pigmentation performance was significantly (p < 0.05) better in the Ax0.6 groups. Interaction between Ax and α-Toc was also found in the Ax content of shrimp body parts. Interestingly, dietary α-Toc helped to reduce the Ax consumption rate, promote the absorption and increase the deposition of Ax in the muscle. Shrimps from the Ax0.6 groups showed significantly (p < 0.05) improved hepatopancreatic digestive enzyme activities compared with those of the Ax0 groups. Although no interactive (p > 0.05) effects were found between dietary α-Toc and Ax on total haemocyte count and tolerance against freshwater, dietary Ax and α-Toc supplementation showed better performance on these two parameters. It was concluded that dietary Ax and α-Toc functioned synergistically, and the shrimp fed with the diet containing 0.6 g Ax/kg diet Ax and 0.2 g α-Toc/kg diet showed improved growth and pigmentation performance compared with the other groups in the current study.

The effects of dietary astaxanthin on intestinal health of juvenile tiger puffer Takifugu rubripes in terms of antioxidative status, inflammatory response and microbiota

The effects of dietary astaxanthin on intestinal health of juvenile tiger puffer <i>Takifugu rubripes</i> in terms of antioxidative status, inflammatory response and microbiota

Effect of dietary astaxanthin on the growth performance, non-specific immunity, and antioxidant capacity of pufferfish (Takifugu obscurus) under high temperature stress.

The present study was conducted to investigate the effects of astaxanthin on growth performance, biochemical parameters, ROS production, and immune-related gene expressions of the pufferfish (Takifugu obscurus) under high temperature stress. The experimental basal diets supplemented with astaxanthin at the rates of 0 (control), 20, 40, 80, 160, and 320mgkg-1 were fed to fish for 8weeks. The results showed that the fish fed diet with 80, 160, and 320mgkg-1 astaxanthin significantly improved weight gain and specific growth rate. Furthermore, fish fed the moderate dietary astaxanthin increased plasma alkaline phosphatase activities, and decrease plasma aspartate aminotransferase and alanine aminotransferase activities. After the feeding trial, the fish were exposed to high temperature stress for 48h. The results shown that astaxanthin could suppress ROS production induced by high temperature stress. Meanwhile, compared with the control group, the astaxanthin groups increased SOD, CAT, and HSP70 mRNA levels under high temperature stress. These results showed that the basal diet supplemented with 80-320mgkg-1 astaxanthin could enhance growth, nonspecific immune responses, and antioxidant defense system and improve resistance against high temperature stress in pufferfish.

Effect of Dietary Astaxanthin on Boar Sperm Quality and Motility after Liquid Storage during the Summer Season

Effect of Dietary Astaxanthin on Boar Sperm Quality and Motility after Liquid Storage during the Summer Season

Effects of dietary astaxanthin and β carotene on gonadosomatic and hepatosomatic indices, gonad and liver composition in goldfish Carassius auratus (Linnaeus, 1758) broodstocks

This study investigated the effects of two source carotenoids on the hepatosomatic index (HSI) and the gonadosomatic index (GSI) of the goldfish (Carassius auratus). For this experiment, six diets containing concentrations of 50, 100, and 150 mg carotenoid kg -1 of synthetic astaxanthin and β-carotene were added to a basic carp diet, while one group of fish was fed a control diet (no added carotenoids). Fiberglass tanks were used for the study, which was performed from January to April of 2013. During the breeding period, the hepatosomatic (HSI) and gonadosomatic (GSI) indices were exa- mined monthly, along with the total carotenoid levels in the ovaries and livers of female goldfish broodstock. A significant positive correlation was observed between total carotenoids in both the liver and ovary tissues and GSI after 90 and 120 days of the experiment. The HSI was not affected by the carotenoid-enriched diets. However, the carotenoid-enriched diets resulted in greater accumulation of carotenoids in the gonads. β-carotene-enriched diets (B150) led to greater accumulation of carotenoids in the liver after 90 days. Lastly, we found that diets containing higher levels of astaxanthin and β-carotene improve the GSI in goldfish broodstock.

Effect of dietary astaxanthin on free radical scavenging capacity and nitrite stress tolerance of postlarvae shrimp, Pleoticus muelleri.

The aim of this study was to investigate the effect of astaxanthin feed supplementation and environmental nitrite stress in postlarvae of Pleoticus muelleri (15 ± 0.004 mg initial weight) under culture conditions. Diets containing three levels of astaxanthin, 0 mg kg(-1) of diet (C0), 100 mg kg(-1) of diet (C(100)), and 300 mg kg(-1) of diet (C(300)), were used. Postlarvae fed with each diet were exposed to different concentrations of nitrite (NO(2)Na) (0-200 mg L(-1)). The 96 h median lethal concentration (LC50) values of nitrite N were 76.3, 89.7, and 157 mg L(-1) for shrimps fed to C0, C(100), and C(300). The scavenging properties were evaluated against the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical by electron resonance spectroscopy (EPR). For all feed treatments, the extracts exhibited strong DPPH scavenging activity; however, shrimp fed with C(100) and C(300) showed the greatest activity to quench DPPH (62 and 59%, respectively) with respect to C0 (43%). It can be concluded that astaxanthin acts as a protector of nitrite stress in P. muelleri.

Effect of dietary astaxanthin against Aeromonas hydrophila infection in common carp, Cyprinus carpio

The effect of astaxanthin at 0, 25, 50, and 100 mg kg−1 incorporated in basal feed on immune response and disease resistance in Cyprinus carpio against Aeromonas hydrophila was investigated. When fed with 25 mg kg−1 diet, the cumulative mortality was 35% whereas it was 10% and 20% with 50 and 100 mg kg−1 diets. With all enriched diets the growth rate increased significantly from week 1 to 4 when compared with control. However, the specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER) did not vary significantly from that of the control except with 50 mg kg−1 diet. When fed with 50 and 100 mg kg−1 diets the red blood cells, white blood cells, hemoglobin, and hematocrit values significantly increased. However, the serum total protein, albumin, and globulin contents significantly increased only when fed with 50 and 100 mg kg−1 diets. The phagocytic ratio also significantly raised with 50 and 100 mg kg−1 diets on week 2 and 4 whereas the phagocytic index significantly increased with all groups only on fourth week. The respiratory burst activity significantly increased in 25 mg kg−1 diet group on first week whereas in 50 and 100 mg kg−1 diet groups the activity increased on weeks 2 and 4; a similar trend was observed in the anti-protease activity only on weeks 2 and 4. The serum lysozyme activity and bactericidal activity registered a significant increase with all enriched diets. This study suggests that supplementation of astaxanthin at 50 and 100 mg kg−1 with the basal diet significantly promotes the growth restores hematology and modulates the immune system in C. carpio against A. hydrophila.

Effects of Dietary Astaxanthin on Innate Immunity and Disease Resistance against Edwardsiella tarda in Olive Flounder Paralichthys olivaceus

We report on the non-specific immune responses and disease resistance against Edwardsiella tarda in olive flounder fed diets supplemented by astaxanthin. Four experimental diets were formulated to be isonitrogenous (45% crude protein) and isocaloric (17.1 MJ/kg, dry matter). Astaxanthin was added to the diets at 0 (control), 1%, 2%, and 3%. Three replicate fish groups (30 fish/tank) were fed one of the experimental diets for 15 days. After 15 days, 30 healthy fish per dietary treatment were selected and injected with 1 ml E. tarda suspension to evaluate the disease resistance of the fish. Dietary supplementation of astaxanthin resulted in significantly higher non-specific immune responses than in fish fed the control diet. Cumulative mortality in the challenge test with E. tarda was significantly lower in fish fed the astaxanthin-supplemented diets than in fish fed the control diet. Results indicate that dietary supplementation of astaxanthin can enhance non-specific immune responses and disease resistance of olive flounder against E. tarda, and that a relatively short feeding period of astaxanthin can improve immunity in fish.

Effects of dietary astaxanthin and ractopamine HCl on the growth and carcass characteristics of finishing pigs and the color shelf-life of longissimus chops from barrows and gilts (2011)

A total of 160 pigs (initially 198 lb) were used to evaluate the effects of increasing dietary astaxanthin (AX, from Xanthophyllomyces dendrorhous yeast) and Ractopamine HCl (RAC) on the growth and carcass characteristics of finishing pigs as well as the color shelf-life of longissimus muscle (LM) chops from barrows and gilts. Pigs were weighed and randomly allotted to 1 of 8 dietary treatments fed for approximately 26 d preharvest. Dietary treatments consisted of a corn-soybean meal-based control diet, the control diet with 7.5, 15, 30, 60, or 120 ppm AX, and a corn-soybean meal-based diet with 10 ppm RAC and 7.5 or 20 ppm AX. Each treatment had 10 pens, with 2 pigs (1 barrow and 1 gilt) in each pen. A split-plot design with repeated measures was used to compare color characteristics of LM chops from individual barrows and gilts.

Effect of dietary astaxanthin on the growth performance, lipid composition and post-mortem skin colouration of red porgy Pagrus pagrus

A 120-day feeding trial was conducted to assess the possible effect of including dietary astaxanthin (ASTX), for different lengths of time prior to harvest, on red porgy growth performance, lipid and fatty acid composition and post-mortem skin colour. Four treatment groups were established with fish of initial weight of approximately 220 g. Control group was fed on a control diet (with no astaxanthin included) for the entire experiment. ASTX60 group was fed for the first 60 days of the trial on the control diet and 60 days before harvest on a diet with 100 mg of unesterified astaxanthin per kg−1 of diet (ASTX diet). ASTX90 group was fed for the first 30 days of the trial on control diet and 90 days before harvest on ASTX diet. ASTX120 group was fed on ASTX diet during the complete experiment. Results showed an enhancement of certain growth parameters due to ASTX diet and feeding period. In addition, a lipid-lowering effect on whole fish and liver was observed with increased feeding time with ASTX diet, as well as a significant variation of liver and head kidney fatty acid profiles. Concerning skin colouration, only ASTX90 and ASTX120 treatment groups presented adequate hue values throughout the 7 days post-mortem, similar to those reported for wild red porgy. However, skin chroma was close to wild specimens in ASTX120 treatment fish only and up to day three post-mortem. Skin lightness (L*) was not affected by astaxanthin inclusion. Feeding red porgy for a period of 90–120 days before harvest on ASTX diet seems to affect red porgy growth performance, lipid content and fatty acid profile. However, to achieve an adequate skin colouration, throughout a post-mortem period of 7 days, ASTX diet should be given 120 days before harvest.

Effects of dietary astaxanthin, ractopamine HCl, and gender on the growth, carcass, and pork quality characteristics of finishing pigs (2010)

A total of 144 finishing pigs (initially 226 lb) were used to evaluate the effects of various levels and sources of added dietary astaxanthin (AX: 0, 2.5, 5, 7.5, and 10 ppm), as well as ractopamine HCl (Paylean), on growth, carcass, and pork quality characteristics of barrows and gilts. Pigs were blocked by gender and weight and randomly allotted to 1 of 9 dietary treatments fed for approximately 26 d pre-harvest. Dietary treatments consisted of a corn-soybean meal-based control, the control with 5, 7.5, or 10 ppm AX from Phaffia rhodozyma yeast, the control with 5 ppm synthetic AX, and the control with 9 g/ton Paylean and 0, 2.5, 5, and 7.5 ppm AX from Phaffia rhodozyma yeast. There were 2 pigs per pen and 8 pens per treatment (4 pens per treatment x gender combination). Overall, barrows had greater (P < 0.01) ADG and ADFI than gilts, while ADG and final BW increased (P < 0.01) and F/G improved for pigs fed Paylean. For carcass characteristics, barrows had greater (P < 0.01) backfat depth and less (P < 0.01) longissimus muscle area and fat-free lean than gilts. Pigs fed Paylean had greater (P < 0.01) HCW, yield, and longissimus muscle area than those that received non-Paylean treatments. Growth performance and carcass characteristics of pigs fed AX were not different than control pigs. Although there were no differences in the initial subjective color scores, the discoloration scores of longissimus chops increased (linear, P < 0.01) daily during 7 d of retail display, and were greater (P < 0.01) for barrow chops on d 7 compared to gilt chops (gender x day interaction, P < 0.01). Also, the overall average discoloration scores and change in d 0 to 3 objective total color were lower (P < 0.01) for gilts and pigs fed Paylean, although the difference between gilts and barrows was smaller when they were fed Paylean (gender x treatment interaction, P < 0.01). Modest differences in measures of pork color during retail display were associated with added dietary AX, but these did not result in an increase in color shelf-life or reduction in the objective measure of total color change. Collectively, these observations indicated a greater (P < 0.01) color shelf-life for chops from gilts and pigs fed Paylean.; Swine Day, Manhattan, KS, November 18, 2010

Effect of Dietary Astaxanthin on Growth, Survival, and Stress Tolerance of Postlarval Shrimp, Litopenaeus vannamei

Abstract The effect of dietary astaxanthin on growth, survival, and stress tolerance was determined in postlarval Litopenaeus vannamei. An experiment was performed with postlarval shrimp (mean initial wet weight 1.2 mg) fed four isoenergic and isonitrogenous diets containing four supplemented levels of astaxanthin (0, 100, 200, and 400 mg/kg diet, respectively). Shrimp fed diets containing 100, 200, and 400 mg astaxanthin/kg diet for 30 d showed higher weight gain (WG, %) and survival compared to the control (without supplementation of astaxanthin). Specific growth rate (SGR, %/day) and final body wet weight (FBW, mg) showed the same pattern as WG. There were no significant differences in growth performance (FBW, WG, and SGR) among the groups fed the diets with astaxanthin supplementation at the termination of feeding trial. Survival of shrimp in the control and 100 mg/kg diet treatments was significantly lower than that of shrimp in the treatments with 200 and 400 mg/kg diet. After 9 d of a stress tolerance test, survival of shrimp in the 200 and 400 mg astaxanthin/kg treatments was significantly higher than that of shrimp in the 0 and 100 mg astaxanthin/kg treatments (P &lt; 0.05). We concluded from this experiment that astaxanthin was a necessary ingredient for the development of larval L. vannamei. Considering the effect of astaxanthin on both, growth performance and survival of postlarval L. vannamei, the level of astaxanthin supplemented in the diet should be between 100 mg and 200 mg/kg of diet.

Effect of dietary astaxanthin on growth and immune response of Giant freshwater prawn Macrobrachium rosenbergii (de man)

Effect of dietary astaxanthin on growth and immune response of Giant freshwater prawn Macrobrachium rosenbergii (de man)

Effects of dietary astaxanthin on the growth performance and carcass characteristics of finishing pigs (2009)

A total of 48 barrows (initially 215 lb) were used to evaluate the effects of increasing dietary astaxanthin (0, 5, 10, and 20 ppm) on late-finishing pig performance and carcass characteristics. Pigs were blocked by weight and randomly allotted to 1 of 4 dietary treatments in a 26-d experiment. Pigs were fed simple corn-soybean meal-based diets. Treatments consisted of a control diet and the control diet with 5, 10, or 20 ppm added astaxanthin. For overall growth performance (d 0 to 26), ADG and F/G of pigs fed astaxanthin was not different from that of the control pigs. However, ADFI tended (linear; P < 0.10) to decrease with increasing astaxanthin. For the comparison of carcass characteristics, pigs fed increasing astaxanthin had decreased average (P < 0.03) and 10th rib (P < 0.06) backfat depth compared with control pigs. Pigs fed 5 or 10 ppm astaxanthin tended to have the lowest (quadratic; P < 0.10) 10th rib fat depth. Pigs fed increasing astaxanthin tended to have increased (quadratic; P < 0.10) standardized fat-free lean and percentage of fat-free lean, and pigs fed 5 or 10 ppm were the leanest. The loin muscle of pigs fed astaxanthin tended to have lower L* and b* (P < 0.06 and P < 0.08, respectively), indicating a darker color. The improved carcass characteristics of pigs fed astaxanthin resulted in a numeric increase in the net profit per pig for those fed 5 and 10 ppm astaxanthin. In conclusion, growth performance of pigs fed 5, 10, or 20 ppm astaxanthin was not different from that of pigs fed the control diet. However, the improved carcass characteristics could be economically beneficial to pork producers. Additionally, the improvements observed in loin color could result in improved consumer acceptance of fresh pork. These results warrant further research.; Swine Day, Manhattan, KS, November 19, 2009

Pigmenting efficacy of astaxanthin fed to rainbow trout Oncorhynchus mykiss: Effect of dietary astaxanthin and lipid sources

The aim of the present experiment was to investigate the effect of two different dietary types of oil (fish oil (FI) and olive oil (OL)) on the pigmenting efficacy of astaxanthin from the green micro-algae Haematococcus pluvialis (ALG) (total amount of carotenoid pigments 32 mg kg−1 on a dry weight basis of which astaxanthin accounted for 98.6%) and from the synthetic astaxanthin (AST) in terms of astaxanthin serum concentration, induced muscle colour, and astaxanthin muscle retention in rainbow trout for 6 weeks. Diets with different oil sources were well accepted by fish. At the end of the experiment there were no significant differences between fish fed different diets in final mean weight, specific growth rate, or feed conversion ratio. Fish fed AST showed higher (P<0.05) serum concentrations than those fed ALG. Moreover fish fed diets OL displayed higher (P<0.05) serum astaxanthin levels than those fed diets FI. Fish muscle colour parameters reacted differently according to fish feed. Over 6 weeks of feeding L⁎ compared to L⁎ of initial sampling time showed a decrease more marked for trout fed ASTFI than ALGFI. Fish fed ASTOL and ALGOL displayed intermediary values. On the contrary the other colour parameters increased except hue H(°)ab which did not show any change whatever diet was fed to the fish. Chroma C⁎, a⁎, and b⁎ data obtained for fish fed AST were higher than those obtained for fish fed ALG. Muscle astaxanthin concentrations were lower (P<0.05) for fish fed algae than for those fed synthetic astaxanthin. After 6 weeks of experiment muscle astaxanthin levels were not different (P>0.05) for fish fed olive or fish oil. Muscle astaxanthin retention was higher (P<0.05) for fish fed AST than for fish fed ALG.