Aquaculture Nutrition最新文献

Yellowfin seabream (Acanthopagrus latus) was basal fed supplemented with low (Mus1: 100 mg/kg) and high (Mus2: 200 mg/kg) doses of lysozyme (200 U/mg) diets, compared to a control group (Mus3: basal fed with no lysozyme) to evaluate lysozyme as an antibiotic alternative. Comprehensive analyses (composition, texture, histological, and untargeted metabolomics) revealed lysozyme promoted growth, muscle development, and flesh quality. Lysozyme supplementation enhanced ash and carbohydrate accumulation significantly (p  < 0.05). Fish in the Mus1 group showed larger muscle fibers and increased myotome density. Metabolomics identified significant shifts in organic acids, lipids, and aromatic compounds. Mus2 enhanced mucosal immunity and retinal accumulation, while reducing fat deposition. Mus1, with a lower lysozyme dose, showed enrichment of the tricarboxylic acid cycle (TCA) cycle activity, accumulating beneficial organic acids (citric and malic acid) and nutritionally critical fatty acids (EPA and DHA), improving muscle quality. This study provides valuable insights into the effects of dietary lysozyme supplementation on yellowfin seabream, with potential applications for optimizing aquaculture practices and identifying key biomarkers for fish health and growth to improve muscle quality and flavor.

This study aims to investigate the effects of potassium diformate (KDF) and sodium propionate (NaP) on gut digestive and immune functions, intestinal microbiota, and lipid metabolites of Trachinotus ovatus based on multiomics approach. Juvenile T. ovatus (initial weight: 8.65 ± 0.02 g) were subjected to a 56-day feeding regimen. Three isonitrogenous and isolipidic diets, including the control (CG), an additional 6.6 g/kg of KDF, and an additional 6.0 g/kg of NaP were fed to juvenile fish twice daily. Results showed that KDF and NaP supplementation significantly increased the activities of chymotrypsin (Chy), lipase (Lip), α-amylase (α-amy), creatine kinase (CK), Na⁺K⁺-ATPase (Na⁺K⁺-ATP), γ-glutamyl transferase (γ-GT), alkaline phosphatase (AKP), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and superoxide dismutase (SOD) as well as the expression level of Nrf2 (p < 0.05), while decreased the pH value, malondialdehyde (MDA) content and the mRNA level of Keap1 (p < 0.05). Dietary KDF and NaP markedly enhanced microbial α-diversity and induced significant shifts in microbiota composition through selective modulation of bacterial populations, such as Photobacterium, Mycoplasma, and Mycobacterium (p < 0.05). Besides, KDF and NaP led to notable alterations in the intestinal metabolite lipidome through increasing short-chain fatty acids (SCFAs) levels, upregulating the abundance of phosphatidylcholine (PC), phosphatidylethanolamine, methyl PC (MePC), lysophosphatidic acid, ceramide (Cer), sitosteryl, monogalactosyldiacylglycerol, coenzyme, and lysophosphatidylethanolamine and downregulating the abundance of sphingomyelin and monoglyceride (p < 0.05). The assessment of associations revealed inverse relationships of digestive and antioxidative indices with Photobacterium, but positive correlations with Mycoplasma, Mycobacterium, Ruegeria, Synechococcus, Nautella, Turicibacter, and Roseovarius. This study advances our understanding of KDF and NaP on intestinal health.

Upcycling meat and fish by-products into bioactive protein hydrolysates promotes zero-waste practices within the circular bioeconomy and provides locally-sourced alternatives to replace fishmeal (FM) in aquafeeds. In this study, novel hydrolysates were developed from blue shark skin, fish by-products, and swine processed animal protein, aiming to reduce the high-quality FM inclusion in European seabass (Dicentrarchus labrax) diets. Four isoproteic (53%) and isolipidic (18%) plant-based diets were formulated: a control (CTRL) diet containing 12.5% FM was compared to three experimental diets, including 3% of each hydrolysate at the expense of FM-protein: SHARK, FISH, and SWINE. Seabass juveniles (13 g) stocked in 160 L tanks (3.9 kg/m³) were fed the diets in triplicate, three times daily until satiety, for 89 days. All diets were equally well accepted, promoting similar feed intake, daily growth index (1.6), and efficient feed conversion ratio (1.0–1.1). All fish at least quadrupled their initial size, but those fed the SWINE diet showed the highest body weight (55 g) and significantly higher condition factor (1.22), hepatosomatic index (HSI) (1.6), and viscerosomatic index (VSI) (8.4). Intestinal integrity remained similar across treatments, and apparent digestibility coefficients (ADCs) of protein and fat were above 96%. Iron (Fe) ADC was at least doubled with hydrolysates inclusion. Whole-body and muscle composition were similar across groups. However, the muscle metabolome of the SHARK-fed fish exhibited higher levels of glycolytic intermediates and lower levels of glucogenic amino acids (AAs) and fumarate, suggesting an increased catabolic activity. However, these changes were not reflected in fish growth performance or muscle flesh quality, which remained similar among treatments.

Metabolic responses to different dietary levels of vitamin D₃ and available phosphorus (avP) was investigated in cultured Atlantic salmon (Salmo salar). The study was carried out in triplicate with a 2-level full factorial design with a center point and three additional points within the design space. Over a 17- week period at the initial weight of 453 ± 9 g, salmon reared indoor on land, were fed diets containing different levels of vitamin D₃ and avP. In summary,growth performance, measured as specific growth rate (SGR), improved when either vitamin D₃ or avP was increased independently, but declined when both were elevated excessively. Bone mineralization was maintained at intermediate vitamin D₃ inclusion levels, though high vitamin D₃ reduced bone ash. A diet containing 0.63 mg/kg vitamin D₃ and 0.70% avP supported growth and mineral retention. A significant reduction in fecal soluble phosphorus when vitamin D₃ was increased in the diet, suggests that management of vitamin D₃ can contribute to improved waste control and reduced environmental load for phosphorus. Finally, the study highlighted that today’s commercial dietary inclusion of vitamin D₃ can result in lower vitamin D₃ accumulation in muscle of land-based farmed Atlantic salmon compared to wild Atlantic salmon.

The optimum period for feeding a broodfish diet combined with manipulated ovulation time, has recently been investigated for egg production capacity, as well as egg and juvenile quality in Atlantic salmon. Here, we report the status of vitamins C, E, D, and K in fish from the same experiment to ensure requirements were met. Two-sea-winter female broodfish were followed through a 17-month growth period, a starvation period on-land until ovulation, and offspring until first-feeding. Throughout all periods, the impact of 9 vs. 17 months of broodfish feed, and early (November), normal (December), and late (February) ovulation on vitamin status was monitored. Vitamin deposition increased with growth, with muscle depositing the highest amounts due to its size. Once the gonads matured, vitamins E, K, and D were similar to muscle, while C was higher. Livers had the highest C, E, and K concentrations, while D was comparable across tissues. During starvation, body stores of C, K, and D declined, while E remained high. All studied vitamins except for C followed the general nutrient deposition profile in unfertilized eggs, increasing from early to late ovulation. K1 was depleted as menaquinone-4 rose, suggesting possible conversion in broodfish and offspring. Ovulation time affected vitamin status more than feeding regime. Vitamin C, E, and most likely K and D levels in both feeding regimes covered the requirements for broodfish and first-feeding fry, regardless of ovulation treatment. However, both early and late eggs and juveniles were of inferior quality, suggesting factors beyond the vitamins examined influenced reproductive outcomes.

Ammonia stress (AS) constitutes a significant environmental challenge that impedes aquaculture development. In this investigation, histomorphology assessments, physiological, and biochemical parameter analyses, and multiomics approaches were employed to elucidate the impact of acute AS on yellow catfish (Pelteobagrus fulvidraco). Findings indicated that serum ammonia concentrations exhibited a dose-dependent increase, correlating with the intensity and duration of stress. As the primary detoxification organ, the liver facilitates ammonia clearance by upregulating genes involved in glutamine and ureagenesis (glutamine synthase [gs], carbamoyl-phosphate synthase [cps], ornithine transcarbamylase [otc], argininosuccinate lyase [asl], argininosuccinate synthase [ass], arginase [arg]), thereby promoting glutamine and ureagenesis while consuming glutamate, argininosuccinic acid, aspartic acid, arginine, and adenosine triphosphate (ATP). Physiological and biochemical data revealed that AS significantly elevated serum glucose, liver triglyceride (TG), and total cholesterol (TC) levels. Histological examination demonstrated a marked reduction in liver glycogen stores alongside a progressive accumulation of lipid droplets proportional to stress severity, suggesting activation of liver glycogenolysis coupled with suppression of lipolysis. Integrative transcriptomic and metabolomic analyses indicated a reprograming of liver energy metabolism characterized by enhanced glycogenolysis and suppressed lipogenesis: liver glycogen content decreased, key glycolytic gene expression (hk1, pdhx) was downregulated, and tricarboxylic acid (TCA) cycle flux was diminished due to decreased cs expression. Concurrently, transcription of fatty acid β-oxidation enzymes (acsbg1, cpt1) was suppressed, leading to palmitic acid accumulation and impaired lipid-derived energy production. Nonetheless, reorganization of carbon flux through upregulation of mdh2 and idh1 facilitated pyruvate utilization in the TCA cycle, promoting NADH generation and sustaining oxidative phosphorylation, as evidenced by increased ATP turnover and content. This study elucidates the metabolic response to AS via increased glycogenolysis. Optimizing liver glycogen reserves serves as a nutritional strategy to enhance ammonia tolerance. Targeted regulation of key genes (pygl, pk, mdh2, idh1) to promote glycogen–pyruvate metabolism may mitigate ammonia toxicity effects and improving aquaculture productivity.

Optimizing bile acids (BAs) inclusion in commercial diets and understanding its molecular mechanisms in Pacific white shrimp (Litopenaeus vannamei) are crucial for improving growth performance. The present study investigated the effect of dietary BAs on shrimp growth and metabolic mechanisms using multiomics approaches. A total of 1800 shrimp (0.16 ± 0.01 g) were fed six diets with BAs levels: 0 mg kg⁻¹ (control, BA0), 50 mg kg⁻¹ (BA1), 100 mg kg⁻¹ (BA2), 150 mg kg⁻¹ (BA3), 200 mg kg⁻¹ (BA4), and 250 mg kg⁻¹ (BA5). After 56 days, the growth performance of BA4 and BA5 groups was significantly higher than the BA0, BA1, and BA2 groups. Regression analysis indicated an optimal dietary BAs level of 216−218 mg kg⁻¹. Biochemical analysis showed that the BA4 group significantly reduced crude lipid content, triglycerides, and nonesterified fatty acids, while increasing digestive enzyme activities. RNA-seq revealed reduced expression of lipid synthesis genes (srebp1, fasn, scd, etc.), while enhancing the expression of genes related to lipid catabolism (acox1, angpt4, dip13a, and gba) and digestive enzymes (prss1 and prss2). Metabolomic analysis showed taurine-conjugated BAs as predominant, with taurine content decreasing likely due to its conjugation with BAs and loss in feces. These results suggest that the optimal BAs level of 216−218 mg kg⁻¹ improved shrimp growth and lipid metabolism by enhancing nutrient digestion, promoting lipolysis, and inhibiting lipid synthesis, without altering the BAs pool balance. This study first revealed taurine’s critical role in Pacific white shrimp BAs metabolism.

The increasing global demand for sustainable seafood calls for innovative solutions that reduce reliance on marine resources. Organic aquaculture, with its focus on environmental sustainability and animal welfare, represents a promising avenue. However, one of the major constraints to its expansion is the limited availability of certified organic feed ingredients. In this study, we evaluated the feasibility of replacing fishmeal (FM) in the diets of meagre (Argyrosomus regius), a promising aquaculture species, by increasing the inclusion of organic pea protein meal (0%, 7%, 18% and 27.5%), while supplementing all pea-protein enriched diets with fixed levels of functional organic ingredients (5% yeast and 2% brown seaweed). Four isoenergetic diets—C (control), PEA 7%, PEA 18% and PEA 27%—were administered to triplicate groups of 40 juvenile meagre over 85 days. We assessed growth performance, feed utilisation, body composition, plasma biochemistry, and gut microbiota composition. All pea protein inclusion levels (7%–27.5%) showed comparable growth to the control diet, with no significant differences in final body weight (PEA 7%: 173 ± 22.5 g; PEA 18%: 189 ± 11.7 g; PEA 27%: 178 ± 23.7 g vs. control: 171 ± 10.0 g) or feed conversion ratio (FCR), demonstrating successful FM replacement up to 27.5%. The PEA 18% group showed superior lipid utilisation with 109% ± 7.21% gross lipid efficiency (GLE; vs. 75.4% ± 10.8% in PEA 7% and 85.3% ± 5.47% in control) and optimal protein metabolism (albumin [ALB]: 0.71 ± 0.07 g/dL vs. control: 0.62 ± 0.05), indicating enhanced nutrient utilisation at intermediate inclusion. High pea inclusion (27.5%) significantly increased beneficial Lactobacillus (8.74% ± 3.30% vs. control: 4.92% ± 3.96%) while maintaining microbial diversity, suggesting pre-biotic effects without dysbiosis. Overall, the results demonstrated that organic pea protein as well as organic seaweed and yeast can be successfully incorporated into meagre diets without compromising growth, feed efficiency, or fish health. These findings highlight the potential of organic pea meal as a sustainable protein alternative to FM in organic aquafeeds for meagre.

The molecular mechanisms underlying species-specific lipid distribution patterns in teleosts remain poorly understood. This study investigated two marine carnivorous species with distinct fat deposition characteristics: the golden pompano (Trachinotus ovatus), which stores lipid in the liver and muscle, and the spotted sea bass (Lateolabrax maculatus), which primarily stores fat in the abdominal adipose tissue. Juveniles (~10.0 g) were fed three iso-nitrogenous diets (45% protein) with graded lipid levels (12%, 14%, and 16%) for 8 weeks. Two-way analysis of variance (ANOVA) analyses revealed significant species × diet interactions affecting lipid distribution (p < 0.05). Golden pompano exhibited higher hepatic/muscular crude lipid and triglyceride (TG) levels than spotted sea bass, whereas abdominal TG content and abdominal fat index (AFI) were lower (p < 0.05). Transcriptomics and qPCR revealed tissue-specific regulatory mechanisms: there was an upregulation of hepatic and muscular fatty acid transport genes (ldlr and fabp), synthesis (g6pd), and deposition (dgat1) with increasing dietary lipid in golden pompano. Additionally, enhanced adipogenesis (c/ebpα and pparγ) and TG storage (dgat1) were observed in the abdominal adipose of spotted sea bass. These findings indicate that lipid accumulation in the liver and muscle of golden pompano is driven by increased fatty acid transport and lipogenesis, while spotted sea bass prioritizes abdominal adipogenesis. This study provides novel insights into the regulation of lipid metabolism in teleosts, with implications for aquaculture feed optimization.

Mugwort leaf powder (MLP), as a typical Chinese herbal medicine containing lots of flavonoids and polysaccharides, has strong anti-inflammatory and immune effects. However, there are relatively few studies on the use of MLP in aquatic animals fed high-fat (HF) diets (HFDs), especially in terms of lipid metabolism and intestinal health. To investigate the impacts of MLP on the growth performance and health status of common carp fed HFDs, common carp were provided with a basal diet, an HFD, and the HFDs enriched with 0.6%, 1.2%, 1.8%, and 2.4% MLP for 8 weeks. Dietary supplementation with 0.6%−1.2% MLP enhanced fish growth and feed utilization compared to the HF group (p < 0.05). Supplementation with over 1.2% MLP increased villus height and digestive enzyme activities (p < 0.05). Supplementation with 1.2% MLP upregulated intestinal anti-inflammatory gene expression and decreased serum triglyceride levels (p < 0.05). Moreover, MLP significantly mitigated the degree of hepatocyte vacuolation and reduced adipocyte size (p < 0.05). Supplementation with over 1.2% MLP decreased the crude lipid, triglyceride, and cholesterol levels in the hepatopancreas, as well as downregulated the lipid synthesis gene expression of fas and upregulated the lipolysis gene expression of cpt1 in the hepatopancreas (p < 0.05). The gene expression related to lipid synthesis in adipose tissue also exhibited a downregulated tendency (p < 0.05). Combining the quadratic regression results of the above indices, this study concluded that supplementation with 0.92%−2.17% MLP positively influenced the growth, intestinal well-being, and lipid metabolism of common carp fed HFDs.