Growth Performance Of Fish Research Articles

Effects of a dietary anionic alkali mineral complex in juvenile olive flounder (Paralichthys olivaceus) during low water temperature season

This study was conducted to investigate the effects of different supplementary levels of an anionic alkali mineral complex (AAMC) containing sodium metasilicate, potassium carbonate, sodium carbonate, sodium tetraborate, sodium chloride, sodium thiosulfate, silver nitrate and sucrose on growth, innate immunity and disease resistance of juvenile olive flounder (Paralichthys olivaceus) during the low temperature season (15.0 ± 2.6 ºC). The control diet was a commercial feed and 0.5%, 1% and 2% of AAMC were sprayed to the control diet to prepare experimental diets (Control, MC-0.5, MC-1.0, and MC-2.0). Quadruplicated groups of juvenile olive flounder (9.11 ± 0.04 g) were distributed in a flow-through system as 45 fish per tank and fed one of the experimental diets to apparent satiation twice a day (08:30 and 16:30 h) for 12 weeks. The dietary supplementation of AAMC improved the feed utilization of fish. Growth performance of fish was significantly improved by feeding MC-2.0 diet compared to control group. Fish fed MC-2.0 diet showed significantly higher blood hemoglobin level compared to the control. Gut morphology of fish was improved by dietary AAMC. Innate immunity and antioxidant capacity of fish were also significantly improved by dietary AAMC. Apparent digestibility coefficient of dry matter was significantly increased in MC-1.0 diet, while protein digestibility was significantly higher in both MC-1.0 and MC-2.0 diets. The cumulative mortalities of challenged fish fed MC-1.0 and MC-2.0 diets were significantly reduced. In conclusion, the dietary supplementation of 2% AAMC significantly improved the growth performance, innate immunity, diet digestibility and disease resistance against Edwardsiella tarda in juvenile olive flounder reared in low water temperature season.

Effect of Spirulina Meal Supplementation on Growth Performance and Feed Utilization in Fish and Shrimp: A Meta-Analysis.

The application potential of spirulina meal in aquaculture feeds has been well summarized in several descriptive reviews. Nevertheless, they converged on compiling results from all possible relevant studies. Little available quantitative analysis regarding the pertinent topics has been reported. This quantitative meta-analysis was performed to investigate the influences of dietary spirulina meal (SPM) addition on responsive variables in aquaculture animals, including final body weight (FBW), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), condition factor (CF), and hepatosomatic index (HSI). The pooled standardized mean difference (Hedges' g) and 95% confidence limit were computed to quantify the primary outcomes based on random-effects model. The sensitivity and subgroup analyses were carried out to evaluate the validity of the pooled effect size. The meta-regression analysis was conducted to investigate the optimal inclusion of SPM as a feed supplement and the upper threshold of SPM usage for substituting fishmeal in aquaculture animals. The results indicated that on the whole, dietary SPM addition significantly improved FBW, SGR, and PER; statistically decreased FCR of animals; had no significant influence on CF and HSI. The growth-enhancing effect of SPM inclusion in the form of feed additive was significant; however, the effect was indistinctive in the form of feedstuff. Furthermore, the meta-regression analysis displayed that the optimal levels of SPM as a feed supplement in fish and shrimp diets were 1.46%-2.26% and 1.67%, respectively. Additionally, up to 22.03%-24.53% and 14.95%-24.85% of SPM as fishmeal substitute did not have a negative effect on growth and feed utilization in fish and shrimp, respectively. Therefore, SPM is a promising fishmeal substitute and a growth-promoting feed additive for sustainable aquaculture of fish and shrimp.

The role of farming practice in nutrient assimilation in small-scale tilapia farming

Subsistence freshwater fish farming is rapidly expanding in developing countries to address food and income security concerns. Despite this significant growth, fish farming practices are often inconsistent, and subsequently many farmers still struggle with low farm productivity. This study compared the growth performance and profitability of two subsistence-level fish farming practices: a common practice in many developing countries (pelleted feed and sweet potato as a supplementary feed) and an alternative practice (pelleted feed and pond fertilisation with NPK) in a small-scale, earthen pond farming setting. We investigated whether farming practice significantly impacts the growth, gastrointestinal microbiota, and the stable isotope profile of Genetically Improved Farmed Tilapia (GIFT) strain Oreochromis niloticus. GIFT reared using NPK were significantly larger (weight: 51.64 g v 24.9 g) and in a better condition (Fulton's K: 1.86 v 1.78) than those reared using vegetables as a supplementary feed. Using a source mixing model of stable isotope results we show that GIFT reared using a common farming method (pellets and sweet potato) acquire the majority (92.9%) of their nutrients from a low protein source, the sediment organic matter (protein = ∼1.25%), possibly explaining their poor growth. In contrast, we found that GIFT reared using an alternative practice (pellets and NPK) assimilate 53.9% of their nutrients from commercial feed pellets, suggesting that the addition of NPK improves their ability to utilise this resource. The microbiota of GIFT reared with NPK could be responsible for this improved growth performance, with its composition correlated positively with fish length, weight, and δ13C. In addition, we identified three bacterial zOTUs; Bacillus, Romboutsia and Patescibacteria whose relative abundance correlated positively with farm profitability, indicating they may represent naturally occurring probiotics. Overall, our results highlight the complex relationship between nutrient inputs, the gastrointestinal microbiota composition, fish growth performance and the profitability of GIFT farms. These findings are important not only for the health status of subsistence fish farmers, but also for improving the livelihoods of wider communities in Papua New Guinea.

Application of fermented product feed to growth performance of fish: A review

Aquaculture activities cannot be separated from the availability of artificial feed, even 70% of the total production cost is spent on feed, so the availability of good feed, in terms of quality and quantity, is an effort to maintain the success of aquaculture activities. Feeds with high protein have relatively higher prices because some of their raw materials still rely on imports from other countries. The solution to this problem is to use alternative feed ingredients that have good nutritional content, are easy to obtain and do not compete with humans. Organic waste originating from food scraps and agricultural industry residues has considerable potential. However, it is necessary to have a fermentation process as an effort to improve the nutrition and quality of these materials. The purpose of this paper is to determine the extent of utilization of fermented organic waste as fish feed ingredients that can help improve fish growth performance.Keywords:Alternative feed ingredientsFermentationFish feedOrganic waste

Dual effect of dietary seaweed of extract nanoparticles (GNS) with bionanocomposite cellulose acetate membranes (CA/bio-AgNps) on growth performance and health status of the Nile tilapia (Oreochromis niloticus): Specification on feed utilization, immune system, and antiparasitic action

Seaweed draws a lot of attention for its vital role in aquaculture as it contains beneficial biological compounds that undoubtedly might help in the development of this field. The current study sheds light on the potential efficiency of dietary supplements of Grateloupia acuminata and G. doryphore (Halymeniaceae) nanoparticles (GNS) at different levels with bionanocomposite cellulose acetate membranes (CA/bio-AgNps) on improved growth performance, digestive enzyme activity, immunity, antioxidative, resistance against infectious pathogens, and characterization of water quality treated with CA/bio-AgNps that is used in rearing Nile tilapia (Oreochromis niloticus). Four concentrations (0.1, 0.25, 0.5, and 1.0 ml/L) of GNS extract were tested as potential anti-bacterial and for the efficacy of being parasitic. Fish with an average weight (24.46 ± 0. 50 g) were apportioned into six experimental groups (T0, T1, T2, T3, T4, and T5) represented as 0.0%, 0.0%, 0.1%, 0.25%, 0.5%, and 1.0% GNS in diets with CA/bio-AgNps, respectively. Injection of fish with Aeromonas hydrophila was performed at the end of the trial. Chemical and bacteriological water indices significantly showed improvement after being treated with CA/bio-AgNps than the control group. Growth, carcass composition, digestive enzyme, and hematological and biochemical indices were significantly noticed positive (p< 0.05), especially T4 and T5, than the control group. In parallel, a significant improvement was noticed in serum lysozyme, total immunoglobulin, complement C3, antioxidative enzyme, and the relative expression of hepatic and inflammatory genes with an increased level of GNS (p< 0.05) are upregulated than the control group. Remarkably, GNS-supplemented diets and extracts provided positive efficacy against A. hydrophila with a decreased percentage of fish mortality, besides efficacy on antibacterial strains and Cichlidogyrus tilapiae, respectively. To sum up, the seaweed extract with CA/bio-AgNps resulted in better growth performance of fish, antipathogenic effect, and health status. Furthermore, CA/bio-AgNps were vital in improving water characteristics. They should be studied and applied more in the future.

Dynamics impacts of oxytetracycline on growth performance, intestinal health and antibiotic residue of grouper in exposure and withdrawal treatment

Little is known about the effects of oxytetracycline (OTC) on marine fish. Using juvenile pearl gentian grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂), we investigated the effects of 56 days dietary oxytetracycline (OTC; OTCD) exposure (80 mg/kg body weight/day) on fish growth performance, intestinal health and antibiotic residue. Meanwhile, the alteration of intestinal health status and antibiotic residue after 7 (O7) or 14 days (O14) OTC withdrawal treatment were explored. We also assessed the potential human health risks based on target hazard quotient (THQ). The results showed that OTC exposure had no effects on growth rate parameters but caused liver and intestine atrophy. OTC exposure impaired the intestinal health by distorting intestinal morphological features, inducing oxidative stress, repressing immune function, triggering NF-κB-mediated inflammatory response and apoptosis, while 7 days OTC withdrawal treatment improved intestinal health status and 14 days OTC withdrawal treatment further improved it. In addition, the order of OTC residue in tested tissues after OTC exposure was: liver > kidney > spleen > muscle > intestine. OTC residue was significantly decreased in all tissues along with the increasing of withdrawal treatment period. Adults and children consuming the edible tissues (muscle) of OTC-treated or withdrawal-treated pearl gentian grouper would not experience any previous health risk as the THQ < 1 in all group.

Effects of dietary Hyssop, Hyssopus officinalis, extract on physiological and antioxidant responses of rainbow trout, Oncorhynchus mykiss, juveniles to thermal stress.

The present study aimed at assessing the effects of dietary Hyssop, Hyssopus officinalis, extract on rainbow trout, Oncorhynchus mykiss, responses to thermal stress. The juveniles (69.8 ± 0.38 g) were stocked in 12 through-flow tanks at a density of 12 fish per tank. Methanolic extract of Hyssop (HME) was added to diet at 0, 100, 250, and 500 mg/kg and the fish were fed (3% of biomass) over a 70-d period: 62 d at 13.3 ± 0.08°C and 7 d at 21-22°C. At the end of the trial, the plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), triiodothyronine (T3), thyroxin (T4), cortisol, glucose, lactate, total antioxidant capacity (TAC), ascorbate, and the gill glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), and malondialdehyde (MDA). The results showed that HME had no significant effects on fish growth performance, survival, and feed efficiency. Dietary 250 mg/kg HME significantly decreased plasma ALT activity (P < 0.001), but showed no significant effects on plasma AST) (P = 0.106) activity, T3 (P = 0.992), and T4 (P = 0.070) levels. Thermal stress significantly (P < 0.001) increased plasma ALT and AST activities, but lowered plasma T3 and T4 levels. Dietary HME and thermal stress had interaction effects on plasma cortisol (P < 0.001), glucose (P = 0.007), lactate (P = 0.010), LDH (P = 0.005), TAC (P = 0.038), ascorbate (P < 0.001), and the gill GPx (P = 0.001), GR (P < 0.001), GST (P < 0.001), and MDA (P = 0.001). Thermal stress significantly increased plasma cortisol, glucose, lactate, and LDH, the gill GPX, GR, and GST, but dietary HME supplementation significantly reduced such elevations, particularly at 250 mg/kg level. Dietary HME significantly increased plasma TAC before the thermal stress and mitigated the stress-induced decreased in TAC, particularly at 250 mg/kg level. Dietary HME significantly decreased the gill MDA before and after the thermal stress, and lowest MDA was observed in 250 mg/kg HME level. Based on the present results, 250 mg/kg HME is recommended as suitable dose to improve antioxidative responses and hepatoprotection in rainbow trout under heat stress.

Evaluation of growth performance, feed efficiency and nutrient digestibility of red hybrid tilapia fed dietary inclusion of black soldier fly larvae (Hermetia illucens)

Insects, particularly black soldier fly larvae (BSFM), Hermetia illucens, have been regarded as promising protein and lipid sources in animal feed, including fish. Digestibility is the key factor that affects nutrient utilization, feeding physiology and efficiency. In the present work, the effect of BSFM on the digestibility of red hybrid tilapia (RHT) compared to fish meal (FM) was ultimately unveiled. A 56-day growth trial was performed with 60 RHT (∼30 g) randomly distributed into six tanks and fed two experimental diets containing FM as a reference diet and BSFM as a test diet. In addition, faeces were collected to determine their chromium concentration and proximate composition. The apparent digestibility coefficient (ADC) of dry matter, crude protein and energy in the BSFM diet were observed to be significantly higher than those in the FM diet. Besides, the growth performance of fish fed with the BSFM diet exhibited significantly higher (P < 0.05) weight gain, specific growth rate, protein efficiency ratio and lower feed conversion ratio than those in the FM group. This study shows that the BSFM feed was well digested by tilapia and improved its growth performance.

Substituting fish meal with castor meal in diets of hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂): Effects on growth performance, immune response, antioxidant and digestive enzyme activities, gut morphology, and inflammatory-related gene expression

The present study was conducted to investigate the effects of replacing fishmeal (FM) with castormeal (CM) on the growth performance, immune response, antioxidant and digestive enzyme activities, intestinal morphology, and expression of inflammatory-related genes in juvenile hybrid grouper (Epinephelus fuscoguttatus♀ ×E. lanceolatus♂). Six iso-nitrogenous (50% crude protein) and iso-lipidic (10% crude lipid) diets were formulated; namely, a reference diet (FM) containing 50% FM and five experimental diets (4% (CM4), 8% (CM8), 12% (CM12), 16% (CM16), and 20% (CM20)) in which FM protein was substituted with CM at varying levels to feed fish (initial weight: 9.12 ± 0.01 g) for 8 weeks. The results showed that the final weight, weight gain rate, and specific growth rate were highest in the FM, CM4, and CM8 groups, whereas the feed conversion ratio, hepatosomatic and viscerosomatic indexes were significantly enhanced in the CM4 group in comparison to the others. The CM4 and CM12 groups were observed to show the highest intestinal length index values compared to the other groups, with the CM20 revealing the worst growth performance. The serum total protein content first increased (P < 0.05) in the CM4 group and decreased (P < 0.05) afterward. Nonetheless, a decreasing significant (P < 0.05) cholesterol and triglyceride contents were witnessed with the increasing replacement of FM with CM. Compared to the control group, a significant increase (P < 0.05) in the activities of serum and liver immunoglobulin-M, superoxide dismutase, glutathione peroxidase, total antioxidant capacity, and complement-3 (except serum activity for CM12 group); liver lysozyme; intestinal amylase, and lipase, was witnessed in the CM groups. However, the serum lysozyme activity was highest (P < 0.05) in the CM4 group and lowest in the CM20 group. While the least serum malondialdehyde contents were observed in the CM4 group, that of the liver malondialdehyde was least witnessed in the FM, CM4, CM8, CM12, and CM16 groups as compared to the CM20. The intestinal histological examination revealed a significantly decreasing trend for villi height and villi width with increasing replacement levels. However, the muscle thickness, crypt depth, and type II mucus cells first increased upto 4% replacement level and later decreased. The increasing of dietary replacement levels significantly up-regulated pro-inflammatory (il-1β, tnf-α, myd88, ifn-γ, tlr-22, and il-12p40) and down-regulated anti-inflammatory (il-10, tgf-β, mhc-iiβ) and anti-bacterial peptide (epinecidin and hepcidin) mRNA levels in the intestine. The mRNA levels of il-6 was up-regulated firstly upto 4 and 8% replacement levels, and later down-regulated with increasing replacement. These results suggested that, although higher dietary CM replacement enhances the immune, antioxidant and digestive enzymes, it aggravates intestinal inflammation. Replacing 4 and 8% of FM with CM could enhance the growth performance of fish.

Effects of dietary malic acid supplementation on growth performance, antioxidant and immunological parameters, and intestinal gene expressions in rainbow trout, Oncorhynchus mykiss

Malic acid (MA) is one of the organic acids that has been less studied for its effects on fish growth performance and gut health. The present study aimed to assess the effects of dietary MA supplementation on growth performance, antioxidant and immunological parameters, and intestinal gene expressions in rainbow trout, Oncorhynchus mykiss. Fish with ∼25 g body weight were randomly distributed into 12 tanks at a density of 15 fish per tank and were fed with diets containing 0 (control), 0.25, 0.5, and 1% MA over 8 weeks. The results indicated that dietary MA persuaded no significant changes in growth performance, feed intake and survival rate. There were elevations in serum alanine aminotransferase (ALT; 0.5 and 1% MA), aspartate aminotransferase (AST; 0.5 and 1% MA), lysozyme (0.25, 0.5 and 1% MA), catalase (CAT; 0.5 and 1% MA), superoxide dismutase (SOD; 1% MA), glutathione peroxidase (GPx; 0.25 and 0.5% MA) activities, and total immunoglobulin (Ig) level (0.5% MA) in the fish MA-supplemented diets, compared to the control. Serum alkaline phosphatase (ALP) activity showed a decrease in 0.5% MA treatment compared to the control. Skin mucus lysozyme (0.25% MA), alternative complement activity (ACH50; 0.5% MA), and total Ig (0.25 and 0.5% MA) showed significant elevations, whereas skin mucus ALP (0.5% MA) exhibited a significant decrease in MA-treated fish, compared to the control fish. Intestinal il-1β (0.5 and 1% MA), hsp70 (0.5% MA), tnf-α (0.5% MA), tgf-β (1% MA), caspase 3 (1% MA), and caspase 9 (1% MA) expressions significantly increased in M-treated fish, compared to the control. In conclusion, this study showed that dietary inclusion of malic acid at the rate of 0.25% in O. mykiss diets improved the antioxidant status and immune responses of fish without any negative effect on growth performance.

Exercise training promotes growth through hypertrophy and enhances capillarization and antioxidant capacity in juvenile largemouth bass (Micropterus salmoides)

Exercise training can improve the growth performance, immunocompetence, and stress resistance of fish, even altering their physiological parameters and gene expression. Largemouth bass (Micropterus salmoides) that originally lived in rivers and lakes are now often raised in ponds without flowing water, leading to a lack of exercise. This study examined the effects of exercise training on largemouth bass (with initial body length 10.68 ± 0.32 cm) growth performance by analyzing white muscle microanatomy and angiogenesis and by measuring antioxidant capacity in muscle and liver. Three water velocities were employed to assess the effects for 60 days: V0 (0 cm/s, control), V1 (13.4 ± 0.4 cm/s), and V2 (26.5 ± 0.9 cm/s). The results showed that: ① both exercise groups had higher feeding rates, and group V1 exercised fish showed significant increases in weight gain, specific growth rate, and final body length. ② Exercise training promoted muscle hypertrophy by increasing fiber cross-sectional area in the group V1. The expression levels of growth-related genes such as insulin-like growth factor-1 (IGF-1), mammalian target of rapamycin (mTOR), and ribosomal protein S6 kinase β 1 (S6K1β) were upregulated, accompanied by inhibition of growth in the group V2 via upregulation of the expression of muscle ring protein 1 (MuRF1) and atrogin-1. ③ Exercise training significantly promoted angiogenesis processes, and the expression of angiogenesis-related genes such as vascular endothelial growth factor A (VEGF-A) and its receptor VEGFR2 was upregulated in liver and muscle. ④ Exercise training reduced the risk of oxidative stress in liver and muscle by increasing antioxidant enzyme activity in the group V1; however, fish in the group V2 had decreased antioxidant enzyme activity and increased malondialdehyde (MDA) and reactive oxygen species (ROS) contents in muscle and thus may have been at risk of oxidative stress. In conclusion, exercise training with an appropriate water flow velocity can stimulate the growth potential of largemouth bass through muscle hypertrophy and enhance capillarization and antioxidant capacity.

Growth performance, antioxidant activities, and immunological responses of hapa-reared thinlip mullet (Liza ramada) juveniles fed on diets supplemented with spirulina (Arthrospiraplatensis)

Spirulina (Arthrospira platensis) (SP) has been utilized for a long time as a valued feed supplement because of its proteinous content and other beneficial phytochemical compounds. Herein, we investigated the influences of SP-supplemented diets on growth, body somatic indices, digestive enzymes, hepatic antioxidant activities, and immunological responses of hapa-reared thinlip mullet (Liza ramada) juveniles. Fish were assigned in six triplicate groups and were fed for consecutive 60 days on the prepared experimental diets containing varying SP levels as 0.0, 2.0, 4.0, 6.0, 8.0, and 10.0 g/kg diet and defined as control (CNT or SP0), SP2, SP4, SP6, SP8, and SP10 groups, respectively. The results indicated that dietary SP supplementation linearly and quadratically improved the fish growth performance, and the highest growth indices were found in the SP8 group. However, dietary SP supplementation did not significantly alter feed conversion ratio (FCR), survival rate (%), hepato-somatic index, and viscera-somatic index among all experimental groups. Meanwhile, digestive enzymes (lipase, α-amylase, and proteases) in the mid-intestine were also linearly and quadratically increased in all SP-fed groups, and their uppermost values were noted in the SP8 group. Hepatic antioxidants such as superoxide dismutase, catalase, and total antioxidant capacity in SP-supplemented groups were significantly elevated than the CNT group. Conversely, hepatic malondialdehyde contents were decreased significantly along with increasing dietary SP-supplementation levels. The immunological parameters such as lysozyme, respiratory burst, and alternative complement activities were significantly elevated in SP-fed groups than in the CNT group. These findings evoked that feeding SP-supplemented diets (especially at 8.0 g/kg diet) significantly promoted the growth, digestive enzymes, hepatic antioxidant status, and immunity of L. ramada juveniles.

The growth performance, antioxidative status and muscle quality of grass carp (Ctenopharyngodon idellus) cultured in the recirculating pond aquaculture system (RPAS)

The recirculating pond aquaculture system (RPAS) consisted of culture ponds, a purification pond, inflow ditch, outflow pipe, ecological ditch, and electrically driven pump. The performance of RPAS on grass carp (Ctenopharyngodon idellus) was explored in this study. In both the RPAS and the traditional pond aquaculture system (TPAS), water quality, fish growth performance, muscle quality, and tissue biochemical properties were assessed. Pond water was exchanged every seven days in RPAS and treated using a purification system that included an ecological ditch and a purification pond with a floating bed and aquatic plant. In RPAS, nitrate‑nitrogen, ammonia‑nitrogen, and nitrite‑nitrogen concentrations were lower than in TPAS. Fish cultured in RPAS exhibited significant higher growth rate and lower feed conversion rate. A significant increase in the expression of growth-related genes of myogenin (MyoG), myofactar-5 (Myf-5), insulin-like growth factor-I gene (igf-1), insulin-like growth factor-II gene (igf-2), and growth hormone receptor gene (ghr) were found in the fish cultured in the RPAS ponds. The content of malondialdehyde in either serum or liver and hepatic protein carbonyls content declined significantly in the RPAS ponds. The activities of T-SOD and GSH in liver and GSH in serum elevated significantly in RPAS fish. Muscular histological characteristics and texture profiles did not alter between two groups. The muscular contents of aromatic amino acids of aspartic acid and glutamic acid were significantly higher in RPAS than those in TPAS. It is inferred that RPAS is beneficial to promote fish growth, decrease oxidative stress, and increase muscle umami flavor.

Using food waste to cultivate safe, good-quality Sabah (giant hybrid) grouper: Dioxins and dioxin-like polychlorinated biphenyls

Dioxins and dioxin-like polychlorinated biphenyls (dl-PCBs) in fish fillet counteract the health benefits of fish products. In this study, food waste was used as a protein alternative to replacing fishmeal commonly used in the commercial fish feed, aiming to cultivate Sabah grouper with acceptable levels of dioxins and dl-PCBs. The concentrations of dioxins and dl-PCBs, as well as the fish growth performance, were compared between the fish groups fed with food waste-based feed (FWBF) and commercial feed (Nanyu®, control). The results showed that the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) (1.22 pg/g dry weight (d.w.)) and non-ortho-dl-PCBs (13.0 pg/g d.w.) were significantly lower (p < 0.05) in the FWBF than in the control feed (commercial feed) (PCDDs: 2.35 pg/g d.w.; non-ortho-dl-PCBs: 27.2 pg/g d.w.). The growth performance of the fish group fed with the FWBF was comparable to that fed with the control feed. There were no significant differences between the WHO2005-TEQ values of different fish fillets (1.00, 1.11, and 1.10 pg WHO2005-TEQ/g d.w. for FWBF group, control feed group, and local market fish, respectively). Based on the guidelines provided by European Food Safety Authority (ESFA) and U.S. Environmental Protection Agency (USEPA), the fish fed with the FWBF were safe for human consumption (hazard index values: 0.284–0.522; cancer risk range: 2.59–2.97 × 10−5). The findings of this study suggest that food waste could serve as an alternative protein source for cultivating Sabah grouper with acceptable levels of dioxins and dl-PCBs.

Ameliorative effects of zeolite and yucca extract on water quality, growth performance, feed utilization, and hematobiochemical parameters of European seabass reared at high stocking densities

The aim of the present study was to evaluate the efficiency of natural zeolite (Z) and Yucca schidigera extract (YE) as water treatments for European seabass, Dicentrarchus labrax, reared at high stocking density. A factorial design was conducted using two socking densities (100 and 200 fingerlings/m3) and five water treatments (control, zeolite 10 g/L, zeolite 15 g/L, YE 0.75 ml/l, and YE 1 ml/L). The fish (with an initial weight of 5.83 g) were allocated into 1 m3 fiberglass tanks in triplicates per each treatment and fed a commercial diet for 45 days. The results demonstrated that rearing European seabass at a high stocking density (200 fish/m3) caused a significant deterioration in water quality parameters, such as dissolved oxygen, NH3-N, NH4-N, NO2-N, and NO3-N by 11.11 %, 49.5 %, 33.33 %, 38.46 %, and 9.09 %, respectively compared to the low stoking density. Furthermore, increasing the stocking density of European seabass significantly reduced growth performance, feed utilization, and various haemato-biochemical parameters. The water treatment with both zeolite and YE significantly improved dissolved oxygen levels and decreased the nitrogen derivatives in tanks water of low and high stocking densities. Also, the water treatments ameliorated the effects of increasing stocking density on fish growth performance, feed utilization, hematological, and biochemical parameters. Whereas the highest wight gain (32.17 g), survival (93 %), and best FCR (1.9) were recorded in group treated with high zeolite level at low stocking density. Regarding the efficiency of both water treatment materials used in this study, water treatment with zeolite at the highest level (15 g/L) outperformed YE in different evaluated parameters of water quality, fish growth, and physiological performance. The mean effects of zeolite and YE at high levels showed an improvement of weight gain and feed conversion ratio by 103.68 %, 46.37 %, 30.90 %, and 23.47 %, respectively, compared to the control. Moreover, the effects of each substrate were level dependent. In conclusion, the water treatment with zeolite and YE could improve the wellbeing and production of seabass fish in favor of zeolite (15 g/l).

Comparative analysis of the haemato‐biochemical parameters and growth characteristics of Oreochromis niloticus (Nile tilapia) cultured under different feed and habitats (biofloc technology and earthen pond system)

Assessing fish haemato-biochemical profile and growth performance is essential to monitor the influence of fish feed and habitat on fish physiology. The influence of two regularly used different commercial feeds and varied environments such as pond and biofloc systems on haemato-biochemical and growth parameters of Oreochromis niloticus was studied by the results of 4-month experiment. Fish ponds and biofloc systems where all the fish were supplied either feed A and B were surveyed weekly. The crude protein content of feed A was 30%, while that of feed B was 28%. Physico-chemical characteristics of water in all culturing systems were suitable for Nile Tilapia production throughout the study period. Results revealed a significant difference (p < 0.05) in most haemato-biochemical parameters. Growth performance was better in fish fed on feed A than feed B in both culture systems. In between, the habitat wide range of haemato-biochemical indices and fish growth parameters were significantly higher in biofloc technology than pond culture system. However, no significant difference (p > 0.05) was recorded in fish enzymatic activities in both systems. Furthermore, it was found that both the length and weight gain were positively associated with the crude protein of the feeds. However, in the case of biofloc, crude protein of both feeds works far better than the pond, as indicated by the p-value and regression R square. Current study delivers the basic knowledge to observe fish blood and growth parameters, which could be essential to understanding the fish culture management and environment.

Influence of dietary sodium taurocholate on the growth performance and liver health of Nile tilapia (Oreochromis niloticus).

Bile acids (BAs) are a class of cholesterol-derived amphipathic molecules approved as new animal feed additives. However, the functional researches mainly focused on BAs mixture, and the influence of the individual BA on fishes was still limited. In the present study, Nile tilapia were fed basal diet with three levels of sodium taurocholate at 0mg/kg (CON), 300mg/kg (TCAL), and 600mg/kg (TCAH) for 8weeks. The results indicated that addition of sodium taurocholate did not significantly influence the growth performance. Instead, TCAH group had higher cholesterol accumulation with liver fibrosis. In TCAH group, the level of nuclear factor E2-related factor 2 (nrf2) signaling-associated oxidative stress factors significantly increased in the liver. Additionally, fish in TCAH group had the highest expression level of genes encoding endoplasmic reticulum (ER) stress and inflammatory cytokines in the liver. In conclusion, 300mg/kg of sodium taurocholate did not significantly influence the growth performance of fish, while 600mg/kg of sodium taurocholate markedly induced cholesterol accumulation and liver injury, suggesting that the application of taurocholic acid in aquafeed should be re-evaluated.

Dietary ferulic acid supplementation improved cottonseed meal-based diet utilization by enhancing intestinal physical barrier function and liver antioxidant capacity in grass carp (Ctenopharyngodon Idellus).

The present study explored the effects of ferulic acid (FA) supplementation in cottonseed meal (CSM)-based diets on grass carp growth performance, feed utilization, liver antioxidation status, and intestinal physical barrier function. Here, four experimental diets supplemented with FA at graded levels (0, 50, 100 and 200 mg/kg) and CSM as the main protein source (384.6 g/kg feed) for an 8-week feeding trial. Our results indicated that 200 mg/kg FA supplementation in a CSM-based diet significantly improved growth performance [including final body weight (FBW), weight gain rate, and specific growth rate] and feed utilization [including feed conversion ratio and protein efficiency ratio] in grass carp (p < 0.05). The results of polynomial regression analysis based on FBW recommended that the optimal dose for FA supplementation was 204 mg/kg. Compared with that no FA supplementation, 200 mg/kg FA supplementation significantly reduced liver malondialdehyde levels and increased glutathione reductase activities (p < 0.05) and 100 mg/kg FA supplementation significantly increased liver total superoxide dismutase activities and reduced blood alanine transaminase levels (p < 0.05). Compared with the control group, 100 mg/kg FA supplementation also led to significantly increased mRNA expression of zo-1, zo-2, occludin, claudin-b, claudin-3, claudin-7a, and claudin-12, encoding intestinal tight junction proteins (p < 0.05). Notably, FA supplementation could reduce lipid deposition by regulating bile acid (BA) secretion. In this study, 100 and 200 mg/kg FA supplementation significantly increased blood and liver total BA levels, respectively (p < 0.05); 100 mg/kg FA also significantly activated mRNA expressions of fxr and cyp7a1 (p < 0.05). Furthermore, the whole-body composition results presented that FA treatment relieved lipid deposition, particularly 50 and 200 mg/kg FA supplementation (p < 0.05). Moreover, triglyceride and total cholesterol levels were significantly lower and high-density lipoprotein levels were significantly higher with 200 mg/kg FA supplementation than with no FA supplementation (p < 0.05). Taken together, the results indicated that FA may be a beneficial feed additive to boost fish growth performance and increase CSM utilization.

Supplementation of the commercial diet of Nile tilapia (Oreochromis niloticus) with DL-methionine and soybean oil under feed restriction

This study aimed to assess the strategy of supplementing the commercial diet of Nile tilapia juveniles with DL-methionine and soybean oil, in BFT culture tanks, by monitoring the water quality, bioflocs composition, and growth performance. The commercial diet daily allowances were restricted by 25% and different levels of DL-methionine (0 and 1) and soybean oil (0, 0.6, and 1.2%) supplementation were carried out, having the delivery of artificial diet as reference. The tanks submitted to feeding restriction exhibited lower concentrations of organic matter, settleable solids and total suspended solid in water. The supplementation of the commercial diet with DL-methionine and soybean oil did not affect the centesimal composition of bioflocs. The combined use of DL-methionine and soybean oil improved the tilapia juveniles’ survival submitted to artificial diet restriction. It was concluded that the supplementation of the Nile tilapia’s commercial diet with 1.0% DL-methionine and 0.6% soybean oil may prevent the reduction of fish growth performance when the artificial diet is allowed restrictively.

Effect of Replacement of Fish Meal by Roasted Guar Korma on Growth Performance of Puntius ticto

A ninety days feeding trial was conducted to evaluate the use of a roasted guar korma as an alternativeprotein source to replacement the expensive fish meal in diets for ticto barb (Puntius ticto). The fiveisonitrogenous experimental diets consisted of a control diet (100% fish meal) and four treatment diets inwhich fish meal replaced with roasted guar korma (25%, 50%, 75% and 100% of dietary protein) wereprepared. The diets were formulated to provide 40% crude protein on a dry weight basis. Total 225 numbersof ticto barb (P. ticto) advanced fry were randomly distributed into five treatments (control + treatment),each in three replicate. They were fed ad libitum during the experimental duration. The daily ration wasdivided into three equal parts and was fed at 08:00 hr, 14:00 hr and 20:00 hr. Based on the results recordedfrom the present experiment, it was found that higher growth, SGR, PER, survival and lowest FCR wereobtained by feeding the fish with the diet (T1) containing 25% roasted guar korma. Proximate compositionof carcass shown negative effect on crude protein and crude lipid decrease with more than 25% of roastedguar korma based diet. Thus, it was revealed that the roasted guar kormareplacing 25% of fish meal in thediet of P. tictoadvance fry gave better growth. Further research on used different plant based proteinsource with addition of essential amino acid, attractant and pigment effect on growth performance of fish.