Growth Performance Of Fish Research Articles

A study of temperature on growth performance in kancra fish (Tor soro) seed maintenance

Kancra fish (Tor soro) is one of specific freshwater fish in Indonesia. The main problem of Kancra fish cultivation is the sustainable availability of seeds. The hatchery efforts are still constrained by environmental conditions that are less supportive, because fish seeds are more sensitive due to environmental changes. Temperature is one of the environmental factors that really affect the hatching rate and seeds growth. The purpose of this experiment is to find out the optimal temperature for Kancra fish culture. Kancra fish with averange initial weight 0.08 ± 0.0001g were used, maintained on aquarium with size of 66×24×30 cm3, with 90 fish/aquarium (density of 3 fish/L). Feeding was done with satiation method (feeding rate of 5%). The treatment was several different water temperatures, which were 24°C, 26°C, 28 °C, 30°C and 32°C. This experiment used completely randomized design with 3 treatments and 3 replications. An automatic heater RH9000 was used to stabilized the water temperature. The best results found on the treatment of 28°C and 30°C with percentage of survival rate 97.74% and 95.52%, and specific growth rate 2.34% and 2.12%.

Probiotic supplementation affects IGF-1 and leptin levels in Nile tilapia hepatopancreatic tissue

ABSTRACT This work aimed to assess the effect of the probiotic strain, Lactobacillus plantarum, on the levels of leptin, IGF-1 and their receptors on the hepatopancreatic tissues of Nile tilapia (Oreochromis niloticus) and then correlate fish growth performance and gut microbiological parameters. Fish juveniles (±23g) were reared in a recirculation system with constant aeration and temperature (25°C). They were distributed into six polyethylene tanks (45L) and fed twice a day at 5% of the tank biomass with the respective diets: control (commercial diet without probiotic) and supplemented with L. plantarum inoculum (1 x 108 CFU mL-1), both in triplicate. After 30 days of feeding, L. plantarum-fed fishes showed greater weekly growth rate, final weight, and feed conversion rate, in addition to higher count of lactic-acid bacteria and lower count of pathogenic bacteria in the intestinal tract, when compared to the control group. The immunostaining intensity for IGF-1 and leptin hormones was lower after L. plantarum supplementation than in the control group, with no change in the level for receptors. This reduction could implicate important changes in fish metabolism and homeostasis.

Fish hydrolysate supplemented diet improved feed efficiency and growth of coral trout (Plectropomus leopardus)

Fish hydrolysate contains hydrolyzed protein which comprised of peptides and free amino acids that are easily digested and absorbed by fish. This study aimed to determine the effectiveness of fish hydrolysate in improving feed efficiency and growth of coral trout. Five experimental diets were formulated to contain 47% protein and 12% lipid with different sources and levels of fish hydrolysate. Diet-1 and diet-2 were added with crustacean hydrolysate at 2% and 4% levels, respectively. Whereas diet-3 and diet-4 were supplemented with 2% and 4% of tuna hydrolysate. Diet-5 was formulated without fish hydrolysate supplementation (control). The diets were prepared as dry pellet with 3 mm diameter. Coral trout juveniles were produced in the hatchery of Institute for Mariculture Research and Fisheries Extension (IMRAFE), Gondol-Bali with the average body weight of 7.6 ± 0.9 g. The juveniles were maintained in 15 fiber tanks, 400L in volume, with a density of 40 fish/tank. The experiment was designed with a completely randomized design (CRD) with 5 treatments (different diets) and 3 replications for each treatment. The fish were fed the experimantal diets three times every day at satiation level for 84 days of feeding experiment. Results of the experiment showed that increased supplementation of fish hydrolysate from 2% to 4% in diet tended to improve fish growth performance. However, the best growth performance, in term of weight gain (WG) and specific growth rate (SGR), was obtained in fish fed diet supplemented with 4% crustacean hydrolysate. This growth performance was significantly higher than of the other treatments (P<0.05). The best feed efficiency (FE) and protein efficiency ratio (PER) were also obtained in fish fed diet supplemented with 4% crustacean hydrolysate. The results of the present study showed that supplementation of 4% crustacean hydrolysate in diet effectively improved the growth and feed efficiency of coral trout.

Enhancement The Growth of Snakehead (Channa striata) with Addition of Dragon Fruit Peel Flour to The Diet

Snakehead (Channa striata) is a fish that grows relatively slowly, but is a typical Sumatran fish with high albumin content and economic value. This makes this fish a very prospect to be developed. Meanwhile, dragon fruit peel is one of the wastes that can be used for diet raw materials and contains vitamins and minerals that have the potential to be useful for increasing growth in fish. This study aims to determine the growth performance of snakehead fed by adding dragon fruit peel flour. This study used test animals, namely snakehead fish juvenile with the size of 1.06 ± 0.02 g/fish. The experiment of fish reared in aquarium measuring of 35cm x 45cm x 90 cm, filled with water as high as 15 cm without aeration. The experiment diets consisted of 5 types, namely feed added with 0% dragon fruit flour (control); 0.5; 1.0; 1.5 and 2.0% of feed. Each treatment was repeated three times. Snakehead was reared for 60 days and fed three times a day on an ad satiation basis. The parameters observed in this study were the survival rate and growth performance of snakehead fish. The results showed that the survival rate between treatments was not significantly different, namely in the range of 97.76 - 100%. Meanwhile, the specific growth rate and feed efficiency of snakehead which added 2% to the diets were the highest, namely 8.66 ± 0.04%/day and 67.83 ± 2.31%/day. The conclusion of this study was the addition of dragon fruit peel flour at 2% enhanced the growth performance of snakehead.

The effects of Terminalia chebula, Terminalia belerica, Phyllanthus emblica and Triphala on the growth performance and immune response in Nile tilapia ( Oreochromis niloticus )

The supplementation of functional feed in aquafeed can enhance immunity, growth performance and survival rate of fish. Triphala is one of the most popular herbal formulations in traditional Ayurvedic medicine. It is rich in gallic, chebulagic and chebulinic acids. Triphala is composed of equal ratios of Terminalia chebula, Terminalia belerica and Phyllanthus emblica. The present study aimed to investigate the effect of each of the three herbal compounds of triphala, as well as triphala itself, on the growth, immunity and plasma biochemistry of Nile tilapia (Oreochromis niloticus). We conducted a 60-day growth trial on Nile tilapia using five different dietary groups: control, Terminalia chebula, Terminalia bellirica, Phyllanthus emblica and triphala. The results showed a negative effect of Terminalia chebula on growth of tilapia, whereas Terminalia chebula and Terminalia bellirica caused signs of abnormal liver health (swollen hepatocytes and absent nuclei), so these two plants appear to have negative effects on fish health when used individually, whereas Phyllanthus emblica and triphala improved growth performance and health of Nile tilapia. Triphala had a positive impact on several plasma biochemical parameters: reduced tChol, triglycerides, LDL, ALT and AST. These results suggest that triphala can improve fish health and boost immunity, without any notable negative side effects, and as such has the potential to be used as a functional feed additive in fish diets. Our results do not support the use of the individual components. The exact mechanisms through which triphala compounds modulate the disease resistance, molecular effects and metabolic responses remain unknown and require further investigations.

Omega-3 fatty acids effectively modulate growth performance, immune response, and disease resistance in fish against multiple stresses

Arsenic pollution and climate change are two major global challenges that have threatened the aquatic environment and to a certain extent led to extinction of aquatic animals. Concerted and accelerated scientific efforts are in progress to restrict the ill- impacts of pollution and climate change in the aquatic ecosystem. In this context, we have conducted a study to delineate the effect of omega-3 fatty acids i.e., eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in mitigating arsenic pollution and temperature stress in Pangasianodon hypophthalmus. Four isocaloric and iso‑nitrogenous diets were prepared viz. control feed (no supplementation), and three treatment groups with combined level of EPA + DHA at 0.2, 0.4 and 0.6%. Fish were reared under arsenic (2.65 mg L−1) and elevated temperature (34 °C) (As+T) stress for 105 days with eight different treatment groups in triplicates. Growth performance, oxidative stress enzymes, stress biomarkers, immunity, lipid profile, bioaccumulation of the arsenic in fish tissues and bacterial infection in terms of cumulative mortality and relative percent survival were altered on exposure of arsenic and temperature stress. Supplementation of combinatorial mixture of EPA + DHA at the rate of 0.2 and 0.4% in the diet led to improved growth performance, anti-oxidative status, immunity of the fish and reduced the infection against Aeromonas hydrophila. Neurotransmitter enzyme, HSP 70 and Vitamin C were significantly enhanced (p < 0.01) with supplementation of EPA + DHA, whereas, total lipid, cholesterol, phospholipid, triglyceride and very low density lipoprotein (VLDL) were reduced (p < 0.01) at 0.2 and 0.4% of dietary incorporation of EPA + DHA. Overall, the present investigation clearly revealed that a novel combination of EPA + DHA at 0.4% has the potential to mitigate arsenic pollution, temperature stress and protect the fish against bacterial infection.

Dietary sodium butyrate supplementation attenuates intestinal inflammatory response and improves gut microbiota composition in largemouth bass (Micropterus salmoides) fed with a high soybean meal diet.

The study aimed to investigate the effects of dietary sodium butyrate (NaBT) supplementation on the gut health of largemouth bass (Micropterus salmoides) fed with a high soybean meal diet. Three isonitrogenous and isolipidic diets were formulated: a high fishmeal group (Control); a high soybean meal group (SBM), in which the 30% fishmeal protein in the Control diet was replaced by soy protein; and an NaBT group, in which 0.2% NaBT was added to the SBM diet. Each diet was fed to triplicate tanks (20 fish in each tank). After 8weeks of feeding trial, the distal intestine and intestinal digesta of the fish in each treatment were sampled. The results showed that fishmeal replacement and NaBT supplementation did not affect fish growth performance. Dietary 0.2% NaBT supplementation improved intestinal morphology, increasing the villus width and villus height and reducing the width of lamina propria. The distal intestine of fish in the control and NaBT groups demonstrated lower activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GPx) and a lower malondialdehyde (MDA) content, compared with the fish in the SBM group. Moreover, the addition of 0.2% NaBT in the feed significantly decreased the expression of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) compared to the SBM diet. PCoA and UPGMA analyses based on weighted UniFrac distances demonstrated that intestinal microbial communities in the NaBT group were closer to those in the control group than to those in the SBM group. In addition, dietary 0.2% NaBT supplementation significantly increased the abundance of Firmicutes and Bacteroidetes and decreased the abundance of Tenericutes at the phylum level. Furthermore, the abundance of Bacteroides, Lachnospiraceae_unclassified, and Lachnospiraceae_uncultured was significantly increased, while that of Mycoplasma was significantly decreased in fish intestine at NaBT group at the genus level. In conclusion, dietary NaBT supplementation had beneficial roles in protecting the gut health of largemouth bass from the impairments caused by soybean meal.

Swimming exercise as potential measure to improve flesh quality of cultivable fish: A review

Swimming performance is viewed as a vital characteristic determining survival in many fish in the natural environment. However, a growing number of studies show that swimming exercise of cultivable fish has been associated with improved flesh quality, to which consumers are paying increasing attention. It includes a variety of aspects with both biological and edible layers. In the current situation, aquaculture in flowing water as an effective and feasible alternative for flesh quality improvement has a promising prospect. The goal of this review is to highlight key studies that have contributed to the influence of swimming exercise on fish growth performance, fibre-type composition, nutritional value and muscular sensory properties, and tries to reveal the underlying mechanisms of flesh quality improvements. In addition, the issues that need to be highly valued in the application of flowing water to aquatic production practices are pointed out.

Optimal dietary L-glutamine level improves growth performance and intestinal histomorphometry of juvenile giant trahira (Hoplias lacerdae), a Neotropical carnivorous fish species

Even though glutamine is a non-essential amino acid, its inclusion in diets can be used as a tool to optimize the intestinal health and growth of fish, reason why it has been considered as a functional amino acid. Thus, the aim of this study was to evaluate the dietary supplementation with different levels of L-glutamine for juvenile giant trahira (Hoplias lacerdae), a Neotropical carnivorous fish species. For this purpose, a completely randomized design with six treatments (diets supplemented with 0.0; 2.0; 4.0; 6.0; 8.0 or 10.0 g/kg of L-glutamine) and five replicates was used. Five hundred ten juveniles of giant trahira (1.69 ± 0.10 g and 4.67 ± 0.10 cm) were divided into 30 circulars tanks (20 L) arranged in a water recirculating system. After 12 weeks of feeding, fish growth performance parameters (survival rate, weight and length gain, feed conversion, specific growth rate, protein efficiency ratio, length, final weight uniformity, carcass yield and intestine length), somatic indices (viscerossomatic, hepatosomatic and intestinesomatic), whole-body chemical composition and intestinal histomorphometry were evaluated. According to the polynomial regression applied, there was a quadratic effect (p < 0.05) of L-glutamine levels on fish weight gain, length gain and length uniformity. The L-glutamine levels that yielded the highest values for these parameters were estimated at 4.83 g/kg, 4.92 g/kg, 4.97 g/kg, respectively. Whole-body chemical composition was not affected by the L-glutamine supplementation. The villi height in the median portion and the muscular tunic thickness in the median and posterior portion of the intestine also exhibited a quadratic trend (p < 0.05). Furthermore, 5.42 g/kg, 5.16 g/kg and 5.21 g/kg, are the respective L-glutamine levels that maximized these metrics. It has been concluded that dietary supplementation with L-glutamine can improve growth performance and intestinal histomorphometry of juvenile giant trahira and at the same time, the optimal level in the diet is between 4.83 and 5.42 g/kg.

Effects of dietary linolenic acid to linoleic acid ratio on growth performance, proximate composition and fatty acid contents of pacu ( Piaractus mesopotamicus )

Freshwater fish have the ability to convert linolenic acid (LNA) into EPA and DHA and linoleic acid (LA) into ARA from elongation and desaturation process. The optimal LNA/LA in aquafeeds formulated with vegetable oils can improve the n-3/n-6 ratio in fish flesh. This study aimed at determining the effects of varying dietary LNA/LA ratios on the growth and proximate composition and fatty acids content in the flesh of pacu, Piaractus mesopotamicus. Juvenile pacu (110 ± 1.6 g) were fed for 60 days with diets containing varying levels of sunflower (SO) and linseed (LO) oils (100SO; 75SO:25LO; 50SO:50LO; 25SO:75LO; 100LO), and performance and proximate composition and fatty acids contents of fish flesh were analysed. Experimental diets did not affect fish growth performance. Although the EPA and DHA content were lower in the fish fed the experimental diets than control diet (fish oil), the complete replacement of fish oil by an approximate proportion of 12SO:88LO, in an optimal LNA/LA ratio (2.2–2.4), represents an improvement in nutraceutical quality of the flesh for human consumption. Fish-fed ideal LNA/LA ratio diets have higher total n-3 fatty acids contents, and higher n-3/n-6 and EPA/ARA ratios, without hampering fish performance and flesh proximate composition.

Dietary inclusion effect of various levels of jack mackerel meal on the growth performance, feed efficiency and whole body composition of rockfish (Sebastes schlegeli)

Inclusion effect of various levels of jack mackerel meal (JMM) acting as feed attractants and/or stimulants in diets on the growth, feed consumption, feed utilization and whole body composition of rockfish was investigated. Three hundred juvenile rockfish were randomly allocated into 15 flow-through tanks. Five experimental diets supplemented with JMM at 0%, 1%, 3%, 5%, and 10% at the expense of anchovy meal were prepared and referred to as the JMM0, JMM1, JMM3, JMM5, and JMM10 diets, respectively. Weight gain, specific growth rate (SGR) and feed consumption of fish tended to improve with dietary levels of JMM. The greatest weight gain, SGR and feed consumption were observed in fish fed the JMM10 diet, followed by the JMM5, JMM3, JMM1, and JMM0 diets, in that order. Condition factor (CF) of fish tended to improve with dietary inclusion levels of JMM. Growth performance, feed consumption and CF of fish tended to improve with dietary inclusion levels of JMM ranging from 0% to 10%.

CONTAINMENT OF SOYBEAN MEAL OF PLANT ESTROGEN DISRUPTS GONADS DEVELOPMENT OF NILE TILAPIA

The objective of this experiment was to study the effect of replacing fishmeal as a protein source in tilapia diets with different percentages of soybean meal on gonadal development and fish fertility. Four diets were tested in which fishmeal was partially replaced by four different soybean meal levels (20, 30, 40 and 50%) in tilapia diets. A histological examination was performed to monitor the development of the gonads. Results showed that the final body weight was significantly affected (P< 0.05) by partial replacement of the fishmeal up to 50%. Histological examination of the gonads showed deterioration in the development of the gonads increased by increasing the dietary percentage of soybean meal. Lower replacement rates (20 to 30%) were less effective unless used for a long time, especially in males. When the replacement ratio was 40-50%, the testicular deterioration was clearly observed by the degeneration of the germinal epithelial tissue and the somatic cells that regulating the testis function. Female gonad was also affected by both low and high replacement rates, which resulted in delayed sexual maturity and increased number of degraded eggs. These negative effects can be attributed to contain soybean meal high levels of plant estrogen. As a conclusion, substituting soybean meal instead of fishmeal as a source of protein up to 50% was significantly affect growth performance of tilapia fish. Moreover, increasing the replacement ratio to 40-50%, significantly hampered the development of gonads and fertility of both sexes of tilapia due to the containment of soybean meal high levels of phytoestrogen. Therefore, it could be recommended to avoid using high levels plant protein in broadstock diets to maintain the fish fertility and fecundity.

EFFECT OF REUSE BIOFLOC WATER ON GROWTH PERFORMANCE, FEED UTILIZATION OF NILE TILAPIA FINGERLINGS (OREOCHROMIS NILOTICUS)

Nile tilapia(Oreochromis niloticus) fingerlings (average weight and length: 20.20 ± 0.20 g, 10 ±0.25 cm)cultivated at reusing water from systems with biofloc technology (BFT) under three treatments: T1: Control, T2: tilapia cultured in reused water biofloc (RW) with adding carbohydrate and T3: tilapia cultured in reused water biofloc (RW) without adding carbohydrate. Nine rectangular tanks (66 x 47 x 44 cm, 75L) were used with stocking densities (400 Fish/m3) for 60 days to investigate fish growth performance, feed utilization, body composition, survival, water quality and also economic evaluation was done. Fish were fed a commercial diet containing 30% crude protein. Growth performance of tilapia was recorded biweekly. Water temperature, dissolved oxygen and pH, were recorded daily, while NO2–, NO3–N; total hardness, carbonate hardness and total suspended solids were recorded biweekly. The body composition of the whole fish was determined at the end of the experiment. Results showed that the best water quality parameters, finial body weight, weight gain, daily weight gain, specific growth rate, final biomass, net yield, PER, FCR, FE, feed intake and economic evaluation were significantly(P 0.05). The present study recommended rearing Nile tilapia in reusing water from systems with biofloc technology (BFT) without adding carbon source for best growth performance and prolonged the useful life, quality of water and reduced overall water consumption.

Dietary supplementation of exogenous probiotics affects growth performance and gut health by regulating gut microbiota in Chinese Perch (Siniperca chuatsi)

Host-probiotics of many fish species have not been applied due to the difficulty in isolation and functional verification, and some exogenous probiotics were confirmed to promote the growth performance of fish. Therefore, this study aims to screen the exogenous probiotics that can be used in the culture of Chinese perch and to explore their mechanism of action. Chinese perch were respectively fed with basal diet (CK) supplemented with Clostridium butyricum CB1 (C), Enterococcus faecalis EF1 (E), Bacillus subtilis BS1 (B), and Lactobacillus plantarum LP1 (L) at 1.0 × 108 CFU/g with equal amount for 8 weeks. After feeding, B group presented significantly higher abundance of Bacillus, Lactobacillus, and Paenibacillus, and L group displayed significantly higher abundance of Lactobacillus than CK group. Above increased probiotics species led to higher intestinal lipase activity in B group, intestinal protease activity in L group, and length of intestinal villi and thickness of intestinal wall in B and L groups through fermentation to reduce pH value and secretion of active substances, thus facilitating the nutrient absorption to improve the weight gain (WG). Additionally, B and L groups respectively exhibited higher abundance level of the infectious diseases-related pathway and lower abundance of Aeromonas, which was responsible for higher expression of pro-inflammatory cytokines (p65-NF-κB, IL-Iβ, TNFα, and PAI) and higher blood immune parameter levels (globulin (GLB), total protein (TP), and lysozyme activity (LZM)), eventually improving survival rate. E group significantly inhibited microbial diversity and abundance of Energy metabolism pathway and Amino acid metabolism pathway, which might the reason for the decrease in crude protein content in whole-fish. C groups significantly reduced the microbial diversity and the length of intestinal villi to affect the host's nutrient absorption efficiency, thus causing a decrease in growth performance. Moreover, the imperfection of intestinal villi may allow more LPS to penetrate into the blood, thereby down-regulating the immune status and inducing inflammation, ultimately reducing survival rate. Above results indicated that Bacillus subtilis BS1 and Lactobacillus plantarum LP1 might be used in aquaculture, and probiotics may affect growth performance and gut health by regulating gut microbiota.

Acidified fish feeds reduce the energetic and physiological costs of digestion in juvenile barramundi (Lates calcarifer)

The optimisation of feed composition is fundamental to maximising fish growth efficiency and performance in sustainable aquaculture. Traditionally this has been achieved through altering the quantity, ratio or type of macronutrients in fish feeds (i.e., proteins, lipids, carbohydrates). Here, we present an alternative approach that centres on reducing the energetic costs associated with digestion to enhance fish growth. Acid secretion to the stomach and recovery from the associated blood alkaline tide (rise in blood pH and HCO3− following the consumption of a meal) contribute to the energetic costs of digestion in fish. In this study, we tested the hypothesis that increasing the acidity of pelleted fish diets would reduce gastric acid secretion, the post prandial alkaline tide, the energetic cost of digestion and enhance the efficiency of converting food into growth. We examined the effect of three isocaloric diets of varying acidity on the growth, physiology and energetic costs associated with digestion in juvenile barramundi (Lates calcarifer). The consumption of an acidified diet in barramundi reduced the requirement for endogenous acid secretion to the stomach, prevented a post-prandial blood alkaline tide and reduced the total energetic cost of digestion by ~45%. This led to a ~ 14% improvement in the conversion of food into fish growth at 14 days. However, the observed improvements in feed efficiency declined over time. At day 28 there was no improvement in the conversion of food into fish growth in fish fed an acidified diet. This study shows that components that make up a feed that have no nutritional value can also be manipulated to improve fish growth efficiency, but further research is required to determine the long-term implications of feeding on an acidified diet in fish. This work provides a new avenue of investigation for fish feed formulation, sustainable aquaculture, gastrointestinal physiology and the energetic costs of digestion in fish.

Glucose injection into the yolk influences intermediary metabolism in adult Nile tilapia fed with high levels of carbohydrates

Nutritional programming is a concept proposed to be applied in the field of fish nutrition to improve the use of new diets in aquaculture. This study aimed to investigate for the first time the effects of a glucose injection into the yolk at the alevin stage on intermediary metabolism and growth in adult Nile tilapia (Oreochromis niloticus) at 32–37 weeks later in the life. The early stimulus was performed through direct microinjection of 2 M glucose into yolk sacs of Nile tilapia alevin. Subsequently, in adult tilapia, the long-term effects of glucose stimulus on growth performance, blood metabolites, chemical composition in the liver and muscle, expression of genes involved in glucose transport and metabolism (glycolysis and gluconeogenesis) and related pathways (amino acid catabolism and lipogenesis) were investigated. Our results showed that, even though early glucose injection had no effect on growth performance in adult fish, very few significant effects on glucose metabolism were observed. Furthermore, to evaluate the potential metabolic programming after a dietary challenge, a 2 × 2 factorial design with two early stimuli (0.85% NaCl or 2 M glucose) and two different dietary carbohydrate intakes (medium-carbohydrate diet, CHO-M; high-carbohydrate diet, CHO-H) was performed between weeks 33 and 37. As expected, compared with the CHO-M diet, the CHO-H diet led to decreased growth performance, higher glyceamia and triglyceridemia, higher glycogen and lipid levels in the liver as well as down-regulation of gluconeogenesis and amino acid catabolism gene expressions. More interestingly, although early glucose injection had no significant effect on growth performance, it enhanced the capacities for lipogenesis, glycolysis and gluconeogenesis, particularly in fish that were fed the CHO-H diet. Thus, the nutritional programming of tilapia linked to glucose injection into the yolk of alevins is always visible at the adult stage albeit less intense than what we previously observed in juvenile.

Effects of magnetic water and feeding rate on growth performance and immunity of Nile Tilapia (Oreochromis niloticus)

Objective: The present study was designed to investigate the effect of magnetic water treatment technique and different feeding rates on growth performance, feed utilization, water quality parameters, chemical composition and intestinal histomorphometric parameters of monosex Nile tilapia (Oreochromis niloticus). Design: Experimental study with a factorial design. Fish: A total of 2880 apparently healthy monosex Nile tilapia (O. niloticus) with an average initial body weight of 69.86 ± 0.8 g were randomly distributed into 18 concreate ponds. Procedures: Experimental fish were fed on commercial diet (30.1% protein and 4600 Kcal GE/kg diet) based on three levels of feeding rate 3, 4 and 5% from fish biomass for both treated and control groups. Water was treated with magnetic waves at 0.2 Tesla (Tesla= 2000 Gauss) compared to the control group water (zero Tesla). Growth performance parameters, feed utilization, chemical composition and intestinal morphometric analysis were calculated in all groups at the end of the experiment after eight weeks. Results: The results indicated that growth performance, feed utilization and intestinal histomorphometric analyses improved significantly (P<0.01) in magnetic water groups compared to control groups at the three levels of feeding rate. In addition, water physicochemical parameters including Ammonia (NH4), Nitrate (NO3), Nitrite (NO2), PH and dissolved oxygen (DO) significantly improved in magnetic water treated groups at the three feeding rate levels. Conclusions and clinical relevance: In conclusion, magnetic treatment of water could improve water quality parameters, fish growth performance, feed utilization, and intestinal histomorphometric analyses at different feeding rate.

Beneficial effects of soybean lecithin and vitamin C combination in fingerlings gilthead seabream (Sparus aurata) diets on; fish performance, oxidation status and genes expression responses

Soybean lecithin (SBL) individually or fortified with ascorbic acid (C) was supplied in fingerlings gilthead seabream (Sparus aurata) diets for 60 days and at the end of the experiment the impacts on fish growth performance, feed utilization, body composition, fatty acids profile and oxidation status were evaluated. The six experimental diets contained three levels of SBL; 0, 20 and 40 g/Kg diet with and without C supplementation (500 mg/Kg diet). Four hundred fifty juvenile gilthead seabream of 0.49 ± 0.02 g initial body weight were randomly housed into 18 tanks (120L) with a stocking density of 25 fish per tank. Results indicated that SBL and C blend supplementation improved fish growth performance and feed utilization compared to SBL alone. A significant increase (P < 0.05) in fish protein content when fish fed on 40 g SBL/Kg supplemented diets regardless of the C fortification (18.84% & 18.99%) . Furthermore, fish lipid content was decreased when SBL was added to the fish diets at 20 g/Kg level with C supplementation (3.81%) and at 40 g/Kg with (3.70%) or without C fortification (3.80%). SBL supplementation significantly increased (P < 0.05) both linoleic and linolenic fatty acid and in contrast, decreased EPA and HUFA contents and also n-3/n-6 ratios. Hepatic and muscular Malondialdehyde (MDA) contents were significantly decreased with increasing the concentration SBL from 20 to 40 g/Kg with C fortification (29.51 to 26.74 and 4.77 to 3.92 nmol/g tissue respectively) and in contrast, Glutathione GSH, reduced GSH levels increased (2.57 to 2.75 and 2.25 to 2.38 umol/mg protein respectively). Glutathione disulfide (GSSG) values were significantly decreased in all groups fed additives-supplemented diets relative to additives-free diet. CAT, NRF2, IGF1 genes expression showed a statistically significant (P < 0.05) up-regulation with increasing SBL supplementation level and the highest expression was in fish fed on 40 g SBL and 500 mg C/Kg supplemented diet. In conclusion, combined supplementation of 40 g SBL and 500 mg C/Kg diet induces better growth rate, modifies fatty acids profile enhances fish physiological competence and supports a potential antioxidant status.

Effects of dietary supplementation with filamentous microalgae (Oedocladium sp. or Tribonema ultriculosum) on growth performance, fillet fatty acid composition, skin pigmentation, and immune response of yellow catfish Pelteobagrus fulvidraco

AbstractA 40‐day feeding trial was conducted to investigate the effect of dietary microalgae Oedocladium sp. or Tribonema ultriculosum supplementation on growth performance, fillet fatty acid composition, skin pigmentation, and immune response of yellow catfish Pelteobagrus fulvidraco. Two hundred and seventy experimental fish (51.19 ± 1.17 g) were distributed among nine net cages (2 × 2 × 2 m3) in a randomized design and were fed diets containing 0% (control), 4% Oedocladium meal (Oedocladium), and 5% T. utriculosum meal (Tribonema) to apparent satiation twice a day. After the feeding trial, a hypoxic stress test was conducted to evaluate the effect of dietary microalgal supplementation on fish immune response. Compared to the control, microalgal supplementation did not affect fish growth performance. Dietary supplementation of T. utriculosum significantly increased fillet contents of palmitoleic acid by 100.44% and eicosapentaenoic acid by 12.51%, while the supplementation of Oedocladium meal in diet significantly increased the fish skin ventral lutein content by 61.6%. In addition, dietary Oedocladium or T. utriculosum supplementation significantly increased the plasma total superoxide dismutase activity (before hypoxic stress) and complement component 3 contents (after hypoxic stress). The addition of T. utriculosum meal also significantly increased the plasma immunoglobulin M content regardless of hypoxic stress. These results demonstrated Oedocladium sp. and T. utriculosum can be used to enhance fillet nutritional quality, skin pigmentation, and fish immune response.

Interactive effects of dietary lipid and nutritional emulsifier supplementation on growth, chemical composition, immune response and lipid metabolism of juvenile Nile tilapia (Oreochromis niloticus)

The objective of this study was to investigate the interactive effects of supplementation with different levels of dietary lipids and a commercial nutritional emulsifier (NE) on the growth, feed utilization, immune response and lipid metabolism of juvenile Nile tilapia (Oreochromis niloticus). A 5 × 2 factorial design was formulated with five lipid supplement levels (0, 15, 30, 45 and 60 g/kg) and NE supplementation (with or without NE at 0.35 g/kg). Nile tilapia with an initial average body weight of 8.06 g were randomly placed in 30 cages and offered one of the ten diets for 8 weeks. The results show that dietary NE supplementation significantly increased the final weight, weight gain and specific growth rate compared with fish fed diets without NE (P<0.05). Interestingly, dietary NE supplementation significantly improved the feed conversion ratio (P<0.05). The supplementation of diets with NE significantly reduced the cholesterol levels (P<0.05). The activities of catalase, superoxide dismutase and glutathione peroxidase significantly decreased as dietary lipid supplement levels increased, but they were significantly improved by dietary NE supplementation (P<0.05). The results also show that the liver malondialdehyde (MDA) content significantly increased as lipid supplement levels increased, while NE supplementation resulted in significantly decreased MDA levels (P<0.05). As dietary lipid supplement levels increased, the crude lipid content of the fillet significantly increased in fish fed a diet supplemented with NE (P<0.05). Moreover, lipase activity was significantly increased when the diet was supplemented with NE (P<0.05). A total of 20 fatty acids were measured in the fillets of fish fed diets supplemented with different lipid levels and NE. Significantly higher levels of polyunsaturated fatty acids, particularly linoleic acid (18:2 n6c), γ-linolenic acid (C18:3 n6) and α-linolenic acid (C18:3 n3), were found in fish fed diets supplemented with NE. In summary, dietary NE supplementation has a positive effect on feed digestion and absorption, resulting in improved fish growth performance, immune response and nutritional value of the muscle due to increased essential fatty acid contents. NE supplementation is particularly effective when it is added to diets with low lipid levels.