The water quality assessment indicated significant distinctions in nitrogen concentration across the treatment groups. Specifically, the F4 versus F5 treatment (p = 0.00478), the F4 versus F6 treatment (p = 0.00283), and the P parameter comparisons between F4 and F6 (p = 0.00215) and F4 and F9 (p = 0.00432) exhibited statistically significant differences. The x² test demonstrated a correlation between feed frequency and muscle fiber frequency (p < 2.2 x 10⁻¹⁷). The most frequent fibers were 10-20 micrometers in F4, F5, F6, and F7 and 30-40 micrometers in F8 and F9. The hepatocytes' area demonstrated a discrepancy uniquely between F5 and F9; the nucleus area, conversely, remained consistent. F5's and F4's net revenue differed by 10% (p = 0.00812), as did F6's and F4's (p = 0.00568). Overall, a feeding regimen of five to six times daily for fingerlings results in superior zootechnical and partial culinary formulas.

The effects of incorporating Tenebrio molitor (TM) larval meal into diets on cytoprotective abilities, cell death pathways, antioxidant capabilities, and intermediate metabolic processes in the hearts, muscles, and digestive systems of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax) are investigated in this study. Ten experimental diets were created, each containing either 0%, 25%, or 50% inclusion of TM levels. Both species exhibited a noticeable induction of Heat Shock Proteins (HSPs) within their muscle tissue when inclusion reached 50%. In contrast, p44/42 Mitogen-Activated Protein Kinase (MAPK) activation demonstrated a rise (p < 0.05) in the muscle and digestive tracts of both species at a 25% inclusion rate. Concerning the apoptotic mechanisms, TM incorporation had no effect on gilthead seabream, although autophagy inhibition might have taken place in the muscle tissue. The European sea bass's muscle and digestive tract tissues showed significant apoptosis (p < 0.05). The heart in both fish species types showed a supplementary reliance on lipids, in contrast to their muscle and digestive tracts. Antioxidant activity in European sea bass significantly (p<0.05) increased compared to gilthead sea bream at a 50% inclusion rate of TM. Cellular responses in various species and tissues, contingent upon diet, are demonstrated, while European sea bass appears more prone to TM inclusion based on these findings.

This study investigated the effects of thymol (TYM) at dietary levels of 0, 1, 15, 2, and 25g/kg diet on growth, digestive performance, immune function, and resistance to Streptococcus iniae infection in the rainbow trout, Oncorhynchus mykiss. In three independent trials, 450 fish (358.44 grams; mean ± standard deviation) were distributed among 15 tanks, with 30 fish in each tank. The fish were fed TYM for sixty days. After the feeding phase, the fish that were fed 15-25g TYM showcased superior growth, heightened digestive enzyme activity, and augmented body protein content in contrast to other dietary groups (P < 0.005). Regression analysis suggested a polynomial pattern in the relationship between growth parameters and dietary TYM levels. Considering the diverse growth characteristics, the ideal dietary TYM level for optimizing FCR was determined to be 189%. A statistically significant improvement (P<0.005) in liver antioxidant enzyme activity (SOD, GPx, CAT), blood immune components (C3, Ig, lysozyme, bactericidal activity, total protein), and mucus components (ALP, protease, lysozyme, bactericidal activity, total protein) was noted in those consuming TYM at 15-25g, in comparison to other dietary groups. TYM intake at dietary levels of 2-25 grams was correlated with a significant reduction in malondialdehyde (MDA) levels in comparison to other experimental groups tested (P < 0.005). Subsequently, the inclusion of TYM in the diet, at levels of 15-25 grams, induced an upregulation in the expression of immune-related genes including C3, Lyz, and Ig (P < 0.005). Conversely, the expression levels of inflammatory markers tumor necrosis factor (TNF-) and Interleukin-8 (IL-8) demonstrated a substantial reduction following the 2-25g TYM treatment (P < 0.05). check details The hematological characteristics of fish were affected by the TYM diet, with a considerable upsurge in corpuscular hemoglobin concentration (MCHC), hemoglobin (Hb), red blood cell (RBC), hematocrit (Hct), and white blood cell (WBC) values in fish given 2-25g TYM relative to control groups (P < 0.005). Besides, there was a considerable reduction in MCV in response to 2-25g TYM administration (P < 0.005). Streptococcus iniae-challenged fish receiving the 2-25g TYM diet showed a markedly superior survival rate compared to those fed other dietary formulations (P<0.005). The present study's findings reveal that the inclusion of TYM in rainbow trout feed promotes growth, strengthens the immune system, and boosts resistance to Streptococcus iniae. check details An enhanced dietary regimen of 2-25g TYM is proposed for fish, based on the conclusions of this study.

GIP is a key regulator in the metabolic pathways governing glucose and lipid. This physiological process necessitates the receptor GIPR, a crucial element in its function. To determine the part played by GIPR in the teleost species, a grass carp GIPR gene clone was generated. Sequencing of the cloned glucagon-like peptide receptor (GIPR) gene revealed an ORF of 1560 base pairs, translating into a 519 amino acid polypeptide chain. Forecasting seven transmembrane domains, the grass carp G-protein-coupled receptor is GIPR. Two predicted glycosylation sites were found within the grass carp GIPR, in addition. In grass carp, the expression of GIPR is widespread throughout different tissues, showing high levels within the kidney, brain regions, and visceral fat. The kidney, visceral fat, and brain displayed a significant decrease in GIPR expression following 1 and 3 hours of glucose treatment in the OGTT experiment. The fast-refeeding protocol revealed a substantial induction of GIPR expression in the kidney and visceral fat of the fasted groups. Moreover, the refeeding groups exhibited a substantial decline in GIPR expression levels. The present study observed visceral fat accumulation in grass carp, a result of overfeeding. Overfeeding grass carp resulted in a marked decrease in GIPR expression throughout their brain, kidney, and visceral fat. Oleic acid and insulin treatment stimulated GIPR expression in primary hepatocytes. Treatment with glucose and glucagon resulted in a substantial reduction of GIPR mRNA levels in grass carp primary hepatocytes. check details According to our current knowledge, this is the first time the biological function of GIPR has been elucidated in teleost organisms.

A comprehensive evaluation of the impact of dietary rapeseed meal (RM) and hydrolyzable tannin on grass carp (Ctenopharyngodon idella) was conducted, identifying the potential function of tannins on fish health when the meal was added to the diet. Eight nutritional plans were formulated. Diets were categorized into two groups: four semipurified diets with 0, 0.075, 0.125, and 0.175% hydrolyzable tannin (T0, T1, T2, and T3), and four practical diets with 0, 30, 50, and 70% ruminal matter (R0, R30, R50, and R70), respectively, matching the tannin profiles of their semipurified counterparts. At the end of the 56-day feeding study, the practical and semipurified groups demonstrated a comparable response with regards to the antioxidative enzymes and associated biochemical indicators. As RM and tannin levels increased, respectively, the activities of superoxide dismutase (SOD) and catalase (CAT) in the hepatopancreas increased, while the glutathione (GSH) content and glutathione peroxidase (GPx) activity also augmented. The malondialdehyde (MDA) content displayed an upward trend in T3 and a downward trend in R70. Intestinal MDA and SOD activity showed an increase as RM and tannin levels rose, while glutathione (GSH) content and glutathione peroxidase (GPx) activity experienced a decrease. Interleukin 8 (IL-8) and interleukin 10 (IL-10) expression levels were elevated by the presence of RM and tannin. A notable difference was observed in Kelch-like ECH-associated protein 1 (Keap1) expression, increasing in T3 and decreasing in R50. Grass carp exposed to 50% RM and 0.75% tannin experienced a 50% induction of oxidative stress, a deterioration of hepatic antioxidant capacity, and intestinal inflammation, as revealed in this study. Hence, the tannin content of rapeseed meal must be taken into account in aquatic animal feed.

A 30-day feeding study was designed to determine the physical characteristics of chitosan-coated microdiet (CCD) and its effect on the survival, growth parameters, digestive enzyme activities, intestinal development, antioxidant defense, and inflammatory response of large yellow croaker larvae (initial weight 381020 mg). Four isonitrogenous (50% crude protein) and isolipidic (20% crude lipid) microdiets were fabricated via spray drying, varying in the concentration of chitosan wall material (0%, 3%, 6%, and 9% weight per volume of acetic acid). Results showed a positive correlation (P<0.05) between wall material concentration and lipid encapsulation efficiency (control 6052%, Diet1 8463%, Diet2 8806%, Diet3 8865%) and nitrogen retention efficiency (control 6376%, Diet1 7614%, Diet2 7952%, Diet3 8468%). In addition, the CCD loss rate was considerably less than that of the uncoated diet. Larvae receiving the 0.60% CCD diet demonstrated significantly elevated specific growth rates (1352 and 995%/day) and survival rates (1473 and 1258%), surpassing the control group (P < 0.005). Larvae consuming a diet containing 0.30% CCD exhibited significantly elevated trypsin activity in pancreatic segments compared to the control group, demonstrating a difference of 447 and 305 U/mg protein (P < 0.05). The leucine aminopeptidase (729 and 477 mU/mg protein) and alkaline phosphatase (8337 and 4609 U/mg protein) activities in the brush border membrane of larvae fed the 0.60% CCD diet were considerably greater than those in the control group, a statistically significant difference (P < 0.05).