A diet containing sodium butyrate (SB) at concentrations of 0g/kg (CON), 2g/kg (SB2), and 20g/kg (SB20) was fed to juvenile largemouth bass until they reached apparent satiation over a period of 56 days. Comparisons of specific growth rate and hepatosomatic index revealed no significant disparity among the groups (P > 0.05). The liver -hydroxybutyric acid concentration, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activities, along with serum triglyceride and total cholesterol, increased substantially in the SB20 group compared to the CON group (P < 0.005), suggesting a noteworthy difference. The SB20 group exhibited a statistically significant increase in the relative expression of fas, acc, il1b, nfkb, and tnfa within the liver tissue, in comparison to the CON group (P < 0.005). The SB2 group's indicators exhibited a similar inclination in their respective changes. PF-07321332 inhibitor The SB2 and SB20 groups showed a considerable decrease in intestinal NFKB and IL1B expression relative to the CON group, statistically significant (P < 0.05). A comparison between the SB20 and CON groups revealed that hepatocyte size was augmented, intracellular lipid droplets accumulated, and hepatic fibrosis worsened in the SB20 group. The intestinal structure remained virtually uniform throughout the different groups. The findings from the aforementioned experiments demonstrated that neither a 2g/kg nor a 20g/kg dosage of SB exhibited any positive impact on the growth rate of largemouth bass; conversely, a substantial dose of SB was correlated with liver fat accumulation and subsequent fibrosis.
The 56-day feeding experiment explored the influence of proteolytic soybean meal (PSM) in the diet on growth performance, expression of immune genes, and resistance against Vibrio alginolyticus in Litopenaeus vannamei. A basal diet was supplemented with six PSM dietary levels, ranging from 0 g/kg to 65 g/kg. There was a notable enhancement (P < 0.05) in the growth performance of juveniles fed over 45g/kg PSM, in contrast to the control. Furthermore, treatments incorporating PSM consistently demonstrated superior outcomes concerning feed conversion ratio (FCR), protein efficiency ratio (PER), and protein deposition ratio (PDR). Across all PSM incorporations, the hepatopancreas demonstrated a considerably higher protease activity, which corresponded to the levels of growth and nutrient utilization. A significant (P < 0.005) elevation of serum enzyme activities, particularly superoxide dismutase (SOD) and lysozyme, was observed in shrimp receiving PSM. A significant reduction in cumulative mortality (P < 0.05) was observed in shrimp fed the 65g/kg PSM supplemented diet, compared to the control group, following a Vibrio alginolyticus injection at 72 hours. Following PSM supplementation, a significant (P<0.005) increase in immune deficiency (IMD) and Toll-like receptor 2 mRNA expression was observed in shrimp gill tissue, potentially indicating an impact on shrimp's inherent immune response. In essence, this research confirms that the partial replacement of soybean meal with PSM results in improved growth and immune performance in the L. vannamei shrimp.
To investigate the regulatory effects of dietary lipids on growth performance, osmoregulation, fatty acid composition, lipid metabolism, and physiological reactions, Acanthopagrus schlegelii were maintained in 5 psu low-salinity water. An 8-week feeding trial was conducted with juvenile A. schlegelii fish, initially weighing 227.005 grams, utilizing six experimental diets. These diets were isonitrogenous and featured increasing levels of lipid content: 687 g/kg (D1), 1117 g/kg (D2), 1435 g/kg (D3), 1889 g/kg (D4), 2393 g/kg (D5), and 2694 g/kg (D6). The study's findings highlight a considerable enhancement in fish growth performance consequent to their consumption of a diet enriched with 1889g/kg lipid. The dietary supplement D4 effectively enhanced ion reabsorption and osmoregulation through increased serum concentrations of sodium, potassium, and cortisol, concurrently elevating Na+/K+-ATPase activity and the expression levels of osmoregulation-related genes in both the gill and intestine. The expression of genes associated with long-chain polyunsaturated fatty acid biosynthesis was markedly enhanced when dietary lipid content increased from 687g/kg to 1899g/kg, particularly in the D4 group, which displayed the highest levels of docosahexaenoic (DHA), eicosapentaenoic (EPA), and their combined ratio. Fish fed dietary lipids at concentrations from 687g/kg up to 1889g/kg, experienced maintained lipid homeostasis by an increase in sirt1 and ppar expression levels. Above 2393g/kg, lipid accumulation became evident. High dietary lipid levels in fish feed contributed to physiological stress, including oxidative and endoplasmic reticulum stress. Ultimately, considering weight gain, the ideal dietary lipid content for juvenile A. schlegelii raised in low-salinity water is determined to be 1960g/kg. These findings signify that the ideal dietary lipid level is associated with boosted growth performance, accumulated n-3 long-chain polyunsaturated fatty acids, enhanced osmoregulatory ability, maintained lipid homeostasis, and the preservation of normal physiological functions within juvenile A. schlegelii.
The unsustainable harvesting practices targeting numerous tropical sea cucumber species globally have contributed to the increased commercial relevance of the Holothuria leucospilota in recent years. The use of hatchery-produced H. leucospilota seeds in aquaculture and restocking programs could support both the recuperation of declining wild populations and the provision of enough beche-de-mer to satisfy the growing market. For the successful development of H. leucospilota in hatcheries, an appropriate dietary strategy must be considered. PF-07321332 inhibitor Five distinct diets (A-E) were formulated with varying ratios of microalgae (Chaetoceros muelleri, 200-250 x 10⁶ cells/mL) and yeast (Saccharomyces cerevisiae, ~200 x 10⁶ cells/mL) to evaluate their influence on H. leucospilota larvae (6 days post-fertilization, day 0). The volume percentages used were 40%, 31%, 22%, 13%, and 4%, respectively. PF-07321332 inhibitor These treatments led to a gradual reduction in larval survival over time, with treatment B, on day 15, showcasing the highest survival rate (5924 249%), two times higher than the lowest recorded in treatment E (2847 423%). In every sampling instance, larval body length in treatment A demonstrated the shortest measurement after day 3, while treatment B displayed the longest, the only divergence from this pattern being on day 15. Treatment B demonstrated the maximum percentage of doliolaria larvae, 2333%, on day 15, while treatments C, D, and E exhibited percentages of 2000%, 1000%, and 667%, respectively, on the same day. No doliolaria larvae were found in treatment A, and treatment B exhibited exclusively pentactula larvae, with a remarkable 333% prevalence. On day fifteen of all treatments, hyaline spheres were found in late auricularia larvae, though they were not notable in the specimens from treatment A. H. leucospilota hatchery success is demonstrably higher when utilizing diets combining microalgae and yeast, which is indicated by enhanced larval growth, survival, development, and juvenile attachment compared to single-ingredient diets. Larvae achieve peak performance when given a combined diet of C. muelleri and S. cerevisiae in the specific ratio of 31. To maximize the production of H. leucospilota, we propose a larval rearing protocol based on our findings.
In several descriptive reviews, the application potential of spirulina meal within aquaculture feeds has been comprehensively explored and documented. Still, their aim was to synthesize results from all suitable studies. Reported quantitative research pertaining to these specific topics remains quite meager. This quantitative meta-analysis investigated how the addition of spirulina meal (SPM) to diets influenced crucial aquaculture animal metrics: final body weight, specific growth rate, feed conversion ratio, protein efficiency ratio, condition factor, and hepatosomatic index. Quantifying the primary outcomes involved calculating the pooled standardized mean difference (Hedges' g), and its 95% confidence limits, within a random-effects model framework. The validity of the pooled effect size was investigated using subgroup and sensitivity analyses. To investigate the ideal incorporation level of SPM as a feed supplement, alongside the maximum substitution level for fishmeal in aquaculture animals, this meta-regression analysis was performed. Dietary supplementation with SPM generally enhanced final body weight, specific growth rate, and protein efficiency ratio, while statistically reducing feed conversion ratio. Notably, no significant impact was observed on carcass fat content and feed utilization index. The inclusion of SPM as a feed additive demonstrably boosted growth, though its impact as a feedstuff was less pronounced. Furthermore, the meta-regression analysis quantified the optimum levels of SPM, found to be 146%-226% for fish and 167% for shrimp, as feed supplements. Despite using SPM as a fishmeal substitute at concentrations ranging from 2203% to 2453% and 1495% to 2485%, respectively, for fish and shrimp, there was no adverse impact on growth and feed utilization rates. In summary, SPM exhibits promising qualities as a sustainable replacement for fishmeal, fostering growth as a feed additive for fish and shrimp aquaculture.
The present investigation aimed to clarify the influence of Lactobacillus salivarius (LS) ATCC 11741 and pectin (PE) on growth performance indices, digestive enzyme activity, gut microbial composition, immune parameters, antioxidant responses, and disease resistance to Aeromonas hydrophila in narrow-clawed crayfish, Procambarus clarkii. For a period of eighteen weeks, juvenile narrow-clawed crayfish (weighing approximately 0.807 grams) underwent a feeding trial, consuming seven different experimental diets. These diets included a control diet (the basal diet), along with LS1 (containing 1.107 CFU per gram), LS2 (containing 1.109 CFU per gram), PE1 (containing 5 grams per kilogram), PE2 (containing 10 grams per kilogram), LS1PE1 (a combination of LS1 and PE1), and LS2PE2 (a combination of LS2 and PE2). By the end of 18 weeks, marked improvements in growth parameters (final weight, weight gain, and specific growth rate) and feed conversion rate were evident across all treatment groups, achieving statistical significance (P < 0.005).