Aquaculture Nutrition最新文献

The purpose of this study was to evaluate the effects of baker’s yeast (Saccharomyces cerevisiae) supplementation on growth, immune-related gene expression, and disease resistance in Nile tilapia (Oreochromis niloticus) during the winter season. Fish (an average 5.17 ± 0.33 g) were fed diets containing four different S. cerevisiae concentrations: 0 g/kg (control; T1), 5 g/kg (T2), 10 g/kg (T3), and 20 g/kg (T4) for 90 days. The results showed that weight gain (WG) and specific growth rate (SGR) were significantly higher in fish-fed the T4 diet compared to the control group (p < 0.05). Additionally, fish-fed the T4 diet showed lower carcass yields but higher fillet yields, along with increased amylase and protease activities (p < 0.05). Significant increases (p < 0.05) in serum lysozyme activity were found in fish-fed the T4 supplemented diet, and elevated myeloperoxidase (MPO) levels were observed in fish-fed the T3 diet. Moreover, upregulation of il-8 transcription in the liver was noted in fish feeding S. cerevisiae (T2–T4) compared to the control group. In a challenge test against Streptococcus agalactiae, survival rates (SRs) were significantly higher in fish-fed the T4 diet compared to the control group (p < 0.05). Interestingly, the lowest bacterial counts were recorded in the T3 group (p < 0.05). These findings suggest that dietary supplementation with S. cerevisiae at 10–20 g/kg enhances growth performance, digestive enzyme activity, immune responses, and disease resistance in Nile tilapia during winter conditions.

Study of precision nutrition provides essential and accurate information on the nutrient requirements for animal growth under various farming modes, to offer guidance for the efficient utilization of compound feed. To evaluate the effects of dietary protein levels on the growth performance, immune response, and health of Macrobrachium rosenbergii reared under high-density conditions, prawns in five groups were cultured with a density at 70 prawns/m³, and fed diets with varying protein levels (40%, 42.5%, 45%, 47.5%, and 50%) and designated as CP40, CP42.5, CP45, CP47.5, and CP50, respectively. Our findings revealed that the prawns in the CP42.5 and CP45 groups exhibited significantly higher weight gain rates and specific growth rates, whereas the feed conversion ratio (FCR) was significantly lower in these groups (p < 0.05). The hepatosomatic index (HSI) of prawns in the CP45 group was significantly higher than the other treatments (p < 0.05). The trypsin activity in the CP45 group was the highest (p < 0.05). Additionally, prawns fed 42.5%–45% protein levels exhibited stronger antioxidant capacity (AOC), with higher total antioxidant capacity (T-AOC), and the activities of catalase (CAT), total superoxide dismutase (T-SOD), and glutathione S-transferase (GST) (p < 0.05), along with a substantial reduction in protein carbonyl (PC) levels (p < 0.05). Analysis of the expression of apoptosis-related genes and hematoxylin-eosin staining revealed that both insufficient and excessive dietary protein levels significantly led to autophagy in the hepatopancreas. The environmental stress tests demonstrated that the survival rate (SR) of prawns in the CP45 group was significantly higher compared to the other treatments (p < 0.05). From a growth and health perspective, our findings revealed that a 42.5%–45% protein level is appropriate for M. rosenbergii cultured under high-density (70 prawns/m³) conditions.

The effects of graded levels of hydrolyzed yeast (HY) supplementation (0.0, 0.5, 1.0, and 2.0 g/kg, i.e., Control, HY0.5, HY1.0, HY2.0, respectively) on growth performance, gut health, and immune responses of juvenile Nile tilapia (Oreochromis niloticus) were assessed in this study. The experiment was conducted in a completely randomized design for 14 weeks, where the treatments were distributed in 16 300-L tanks with four replicates each. Despite no significant differences, the final body weight and weight gain were numerically higher in treatments containing HY (44.7 and 34.7 g, 43.5 and 33.5 g, and 45.5 and 35.5 g in HY0.5, HY1.0, and HY2.0, respectively). Feed efficiency (FE) was improved linearly (p < 0.05) with increasing dietary HY level (0.65, 0.70, and 0.72, respectively). Similarly, there was also a significant linear relationship between protein deposition (PD), as well as protein and energy retention efficiency (ERE), with the increasing dietary HY level. Among the blood parameters, only the hematocrit (HCT) value was significantly lower in HY1.0 and HY2.0 compared to the control and HY0.5 treatments. Gut histology showed significantly higher villi length in fish fed HY2.0 diets (795 ± 89.6 µm) compared to those fed the control diet (504 ± 80.7 µm). The average surface volume (SV) of the villi was also higher in tilapia fed HY0.5, HY1.0, and HY2.0 diets (0.025, 0.026, and 0.038 mm³, respectively) compared to the control diet (0.021 mm³). All four target genes were significantly upregulated in HY1.0 and HY2.0 treatments. The expression of the genes supporting growth and ATP production, insulin-like growth factor-1 (IGF-1) and glyceraldehyde-3-phosphate (G-3-P), respectively, was significantly improved, as well as the expression of the immune-related gene, hepcidin. The expression of ghrelin also showed a significant increase with increasing HY levels. It can be concluded that the HY supplementation improved feed utilization, gut health, nutrient absorption capacity, and immunity in Nile tilapia.

An 8-week feeding trial was conducted to assess the effects of hydrolyzed feather meal (HFM) as a fish meal replacement on the growth performance, flesh quality, skin color, and intestinal microbiota of yellow catfish (Pelteobagrus fulvidraco). Five isonitrogen (44% crude protein) and isolipidic (8.5% crude lipid) diets were formulated with varying levels of HFM at 0% (FM, control), 2.05% (HFM2), 4.10% (HFM4), 6.15% (HFM6), and 8.20% (HFM8), corresponding to fish meal replacement of 0%, 8.33%, 16.67%, 25%, and 33.33%, respectively. Results indicated that the growth performance declined significantly as HFM inclusion increased. Based on the results of weight gain rate (WGR) and specific growth rate (SGR), the maximal replacement levels of fish meal with HFM for yellow catfish should be 16.67%. Intestinal enzyme activities, including trypsin, lipase, amylase, and Na⁺–K⁺–ATPase as well as villus height, muscular thickness, and goblet cells number were significantly enhanced in HFM groups. Fish meal replacement with HFM remarkably reduced serum immune indicators acid phosphatase, immunoglobulin M, Complement 3, and Complement 4 levels and significantly increased serum aspartate aminotransferase, total triglycerides, and cholesterol levels, indicating compromised immune function and liver health. The content of collagen and flavor-enhancing amino acids (glutamic acid [Glu], glycine [Gly], and alanine [Ala]), as well as muscle hardness were distinctly boosted, demonstrated an elevated flesh texture led by dietary HFM inclusion. The abnormal skin coloration induced by pigmentary disorders was observed in high HFM inclusion groups, the black pigmentation on dorsal and yellow pigmentation on the abdomen exhibited a gradual reduction in intensity. The study found that replacing up to 16.67% of fish meal with HFM in yellow catfish diets maintained growth performance and improved meat quality. However, high HFM levels damaged serum immune system and caused liver dysfunction, dyslipidemia, pigmentary disorders, and reshaped intestinal microbial structure.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an essential component in regulating oxidative stress. Sulforaphane (SFN) is a natural antioxidant and gene Nrf2 agonist that can increase the antioxidant capacity of the organism and reduce oxidative stress. However, research on the repair of oxidative stress damage by SFN in aquatic animals remains extremely scarce. In order to further explore the function and role of SFN in the repair of oxidative stress injury in aquatic animals, this study took Litopenaeus vannamei as the research object. We established an oxidative stress model of L. vannamei through 6% oxidized fish oil (OFO) feeding. Methods, such as RNA interference (RNAi), qPCR, histopathological analysis, and TUNEL assay, were used to detect the changes in the oxidative stress status of L. vannamei. The results showed that the expression of Nrf2 in the hepatopancreas of L. vannamei in the double-stranded RNA (dsRNA)-Nrf2 + SFN group was significantly higher than that in the dsRNA-Nrf2 group and control group at 24 h (p < 0.05). The transcription levels of antioxidant and autophagy genes in the SFN group were significantly higher than those in the control group (p < 0.05), and the expression of related genes in the dsRNA-Nrf2 + SFN group was also higher than that in the dsRNA-Nrf2 group. Histopathology showed that Nrf2 knockdown would aggravate hepatopancreatic apoptosis and vacuolation, while SFN treatment after Nrf2 knockdown could alleviate hepatopancreatic injury and apoptosis caused by OFO. The results indicated that SFN could repair the oxidative stress injury of L. vannamei induced by OFO by activating Nrf2. This study investigated the role of SFN in alleviating and repairing the oxidative stress damage in L. vannamei caused by OFO, aiming to provide a theoretical basis for the research on the antioxidant effect of SFN and the regulation of the antioxidant capacity of shrimp.

In mammals, cholesterol accumulation in tissues often results in health damage, such as oxidative stress. In contrast, the adverse effects of cholesterol accumulation on the physiological health of fish remain largely unexplored. The present study investigated the impacts of cholesterol accumulation on oxidative stress and the potential mechanisms involved in Nile tilapia (Oreochromis niloticus). Thus, Nile tilapia were fed either a control diet (C) or a high-cholesterol (1.6%, HC) diet for 8 weeks. The viscero-somatic (VSIs) and hepatosomatic indices (HSIs) were increased significantly in fish fed the HC diet and, in accordance, HC intake caused the accumulation of cholesterol in the liver, intestine, head kidney, and spleen. Intake of the HC diet, affected oxidative stress as evidenced by elevated malondialdehyde (MDA) levels in the liver and head kidney and reduced catalase (CAT) activities in the liver and spleen, while SOD activities were increased in the spleen and intestine. Moreover, cholesterol accumulation induced endoplasmic reticulum (ER) stress, inflammation, and apoptosis in the liver and head kidney, as evidenced by increased expression levels of key genes. Metabolome analysis indicated that metabolite levels in tilapia fed the HC diet were primarily enriched in glutathione metabolism and the tricarboxylic acid cycle (TCA), with significantly reduced levels of glutamine, glutamate, glycine, citrate, isocitrate, aconitate, malate, and oxalate. In addition, transmission electron microscopy (TEM) analysis showed accumulation of lipid droplets and distinct alterations in the morphology of mitochondria within hepatocytes of tilapia fed HC. Moreover, significantly increased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were found in fish fed the HC diet. Overall, the data suggested that HC intake induced oxidative stress, which might be associated with impaired antioxidant capability and mitochondrial function, as mitochondria are the primary site of producing cellular reactive oxygen species (ROS). The present study is the first to report the impacts of cholesterol accumulation on oxidative stress and health damage in fish, and suggested targeted cholesterol-lowering interventions as a promising therapeutic strategy for addressing health issues in aquatic animals.

A 60-day research was conducted to evaluate the influence of dietary fish oil (FO) and selenium nanoparticles (SeNPs) on performance of Penaeus vannamei juveniles (2.4 ± 0.0 g) reared in seawater (SW) or hypersaline (HS) water conditions. A 2 × 2 × 2 factorial research was designed with two FO levels, including 3% and 6%, two SeNPs dosages, including 0.4 and 0.8 mg/kg and two water salinity, including SW (35 g/L) and HS (50 g/L). Eight experimental groups were designed as follow: (1) FO₃Se^0.4SW (3% FO + 0.4 mg/kg SeNPs reared in SW), (2) FO₃Se^0.8SW (3% FO + 0.8 mg/kg SeNPs reared in SW), (3) FO₆Se^0.4SW (6% FO + 0.4 mg/kg SeNPs reared in SW), (4) FO₆Se^0.8SW (6% FO + 0.8 mg/kg SeNPs reared in SW), (5) FO₃Se^0.4HS (3% FO + 0.4 mg/kg SeNPs reared in HS), (6) FO₃Se^0.8HS (3% FO + 0.8 mg/kg SeNPs reared in HS), (7) FO₆Se^0.4HS (6% FO + 0.4 mg/kg SeNPs reared in HS), and (8) FO₆Se^0.8HS (6% FO + 0.8 mg/kg SeNPs reared in HS). Four hundred and eighty P. vannamei were randomly distributed into 24 250-L cylindrical fiberglass tanks. Each experimental group was replicated in three tanks (20 shrimp/tank). Shrimps were fed at 5% of their initial biomass three times daily. Water temperature and dissolved oxygen levels were maintained at 31.5 ± 1.2°C and 5.5 ± 1.0 mg/L, respectively. Shrimp in FO₆Se^0.4SW and FO₆Se^0.8SW had higher weight gain (WG) compared to those in FO₃Se^0.8SW and FO₃Se^0.4HS (p < 0.05). Rearing shrimp in HS water increased whole-body protein and ash contents but reduced moisture level. The amount of docosahexaenoic acid (DHA) in FO₃Se^0.4SW, FO₆Se^0.4SW, FO₆Se^0.8SW, and FO₆Se^0.4HS was relatively higher than the other treatments. The antioxidant activities, including glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) level decreased and malondialdehyde (MDA) content in hepatopancreas increased in shrimp reared in HS water. Finally, the transcription levels of insulin-like growth hormones and immune-related genes, including lectin (lec), peneidine 3 (pen-3), prophenoloxidase (propo), and lysozyme (lyz) increased by increasing dietary FO level of 6%. Additionally, these levels were modulated by the interaction of water salinity and dietary SeNPs and FO levels. Based on the findings of the current study, increasing the dietary FO level to 6% and incorporating a moderate level of SeNPs (0.4 mg/kg) were found to enhance P. vannamei tolerance to HS water.

Aquaculture and animal producers are increasingly exploring natural additives such as Stevia rebaudiana for their health-promoting and sustainability-enhancing roles. Known primarily as a sweetener, S. rebaudiana also contains bioactive compounds, such as stevioside and rebaudioside A (Reb A), which exhibit antibacterial, antioxidant, immunomodulatory, and metabolic benefits. Recent studies suggest that these compounds may also exert prebiotic-like activities by modulating the gut microbiota, promoting the growth of beneficial bacterial populations (e.g., Lactobacillus, Bifidobacterium spp.), and improving intestinal integrity, thereby contributing to enhanced nutrient absorption and immune competence. This review highlights the potential of S. rebaudiana in animal feed and aquaculture, demonstrating its ability to enhance growth performance, strengthen immune systems, regulate fat metabolism, and improve overall animal health. Its role as a functional feed ingredient is further emphasized by its capacity to reduce oxidative stress and enhance product quality in both aquatic and terrestrial species (e.g., carp, mullet, tilapia, shrimp, laying hens, broiler, and goats), all of which align with established markers of prebiotic efficacy. By incorporating S. rebaudiana into animal and aquaculture diets, producers may not only improve animal productivity and welfare but also address sustainability challenges by reducing reliance on synthetic additives and antibiotics. Thus, S. rebaudiana represents a promising, multifunctional ingredient with potential prebiotic activity, supporting both animal health and environmentally responsible agricultural practices.

To investigate the most effective feeding level for red-tail catfish (Hemibagrus wyckioides) raised in land-based circular tanks and the impact of feeding levels on H. wyckioides at the molecular and omics levels, we conducted a 56-day experiment using the fish fries (16.49 ± 0.44 g). Three groups were established with varying feeding levels: 2% (T2), 3% (T3), and 4% (T4) of body weight per day. We compared conventional growth and physiological parameters, transcription levels of antioxidant activity, transforming growth factor (tgf), inflammatory factors, and lipid metabolism genes as well as intestinal microbiota and metabolomics. Our results showed that the feed conversion rate (FCR) in the T2 group was significantly lower than those in the other groups, but there were no significant differences in specific growth rate (SGR) and weight gain rate (WGR) among the groups. The T2 group had significantly higher level of albumin compared to the T4 group, while total protein (TP) and low-density lipoprotein cholesterol (LDL-C) levels were significantly lower than the T3 group. The T2 group also have significantly higher activities of superoxide dismutase (SOD) and alkaline phosphatase (ALP) compared to the other groups, and both alanine transaminase activity and goblet cells (GCs) were markedly elevated in the T2 group compared to the T3 group. Additionally, the T2 group had the lowest Firmicutes/Bacteroidetes ratio, with an increase in Turicibacter and Clostridium. The differential metabolites in the T2 group were significantly upregulated in amino acid metabolism and lipid metabolism-related pathways. The expression levels of antioxidant genes, tgf, anti-inflammatory factors, and lipid metabolism genes were all markedly elevated in the T2 group. These findings suggest that the optimal feeding level for H. wyckioides was 2% of body weight per day. These results can serve as a guide for the scientific aquaculture of H. wyckioides.

The Chinese mitten crab (Eriocheir sinensis) is an economically important crab species in China, with a unique flavor, excellent nutritional quality and popularity with consumers. However, the current research on Chinese mud crabs predominantly centers on fresh samples and gives limited attention to the flavor characteristics of crabs after steaming. Consequently, this study aims to explore the flavor differences in crab roe and crab paste following steaming across three distinct aquaculture environments: lakes, ponds, and paddy fields. The overall flavor profile was analyzed by electronic nose and electronic tongue. Nonvolatile and volatile substances were determined by HPLC and SPME-GC–MS-O. Subsequently, the taste intensity values (TAVs) and relative odor activity values (ROAV) were calculated. The results demonstrated that the electronic tongue and electronic nose were capable of distinctly discriminating the differences in crab roe and crab juice among the three types of farmed crabs. The levels of umami amino acids and the equivalent umami concentration (EUC) in the roe and paste of pond crabs (PC) were significantly higher compared to those of lake crabs (LC) and rice-field crabs (RC). Significant variations were observed in both the content and types of flavor compounds in the roe and paste of crabs originating from different aquaculture environments. This study provided a basis for improved understanding of the mechanisms of flavor formation in the Chinese mitten crab and provided a basis for regulating its flavor quality.