Concerning water quality, the nitrogen concentrations in the treated water varied significantly between treatment groups F4 and F5 (p = 0.00478), F4 and F6 (p = 0.00283), and F4 and F9 (p = 0.00432) as well as P between F4 and F6 (p = 0.00215). The x² test displayed a relationship between feed frequency and muscle fiber frequency (p < 2.2 x 10⁻¹⁷). Specifically, fibers of 10-20 micrometers were most prominent in F4 through F7, and fibers of 30-40 micrometers were most prominent in F8 and F9. Variations in hepatocyte area were exclusive to the comparison between F5 and F9, while the nucleus area showed no variations. A 10% difference in net revenue was observed between F5 and F4 (p = 0.00812), and between F6 and F4 (p = 0.00568). To conclude, fingerlings fed at a rate of five to six times per day manifest more advantageous zootechnical and partial culinary recipes.
This study investigates the effects of dietary Tenebrio molitor (TM) larvae meal on cytoprotection, cell death signaling, antioxidant systems, and metabolic processes in the hearts, muscles, and digestive tracts of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax). To assess the consequences of TM inclusion, three distinct dietary regimens were produced, each containing either 0%, 25%, or 50% of the total TM. The induction of Heat Shock Proteins (HSPs) was evident in the muscle tissue of both species at a 50% inclusion rate. 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. With respect to the apoptotic system, the presence of TM had no effect on gilthead seabream, but muscle tissue might have experienced an autophagy reduction. European sea bass muscle and digestive tract exhibited significant apoptosis (p < 0.05). Compared to muscle and digestive tract tissues, the lipid-based energy source seemed to be more crucial for the heart function of both fish species. Antioxidant activity in European sea bass significantly (p<0.05) increased compared to gilthead sea bream at a 50% inclusion rate of TM. The current findings illustrate how diet triggers species- and tissue-specific cellular responses, where European sea bass presents increased vulnerability to TM inclusion.
Dietary levels of thymol (TYM), 0, 1, 15, 2, and 25g/kg, were used in this study to assess its impact on growth, digestive function, immune response, and resistance to Streptococcus iniae infection in the rainbow trout, Oncorhynchus mykiss. A total of 450 fish, weighing 358.44g on average with a standard deviation, were placed in 15 tanks in three separate groups. Each tank contained 30 fish. The fish were fed TYM for 60 days. Post-feeding, fish consuming 15-25g of TYM exhibited accelerated growth, elevated digestive enzyme activity, and greater body protein content compared to those on alternative diets (P < 0.005). Dietary TYM levels exhibited a polynomial relationship with growth parameters, as determined by regression analysis. Given the differing growth patterns, the most advantageous dietary TYM level for feed conversion rate (FCR) was 189%. Ingestion of TYM at levels of 15-25 grams resulted in a significant increase in liver antioxidant enzyme activity (superoxide dismutase, glutathione peroxidase, catalase), blood immune components (alternative complement activity, total immunoglobulin, lysozyme activity, bactericidal activity, and total protein), and mucus components (alkaline phosphatase, protease activity, lysozyme activity, bactericidal activity, and total protein), compared to other diets (P<0.005). A notable reduction in malondialdehyde (MDA) levels was observed in experimental groups consuming TYM at dietary levels of 2-25 grams, a result statistically different from other groups (P < 0.005). Importantly, dietary levels of TYM between 15 and 25 grams positively impacted the expression of immune-related genes such as C3, Lyz, and Ig (P < 0.005). Unlike other observations, the expression of inflammatory factors tumor necrosis factor (TNF-) and Interleukin-8 (IL-8) was significantly reduced after exposure to 2-25g TYM (P < 0.05). see more Fish exposed to a TYM-containing diet (2-25g) demonstrated a significant elevation in hematological markers, encompassing corpuscular hemoglobin concentration (MCHC), hemoglobin (Hb), red blood cell (RBC), hematocrit (Hct), and white blood cell (WBC), in contrast to fish fed other diets (P < 0.005). In parallel, a significant drop in MCV was observed in the context of 2-25g TYM administration (P < 0.005). A 2-25g TYM diet yielded significantly higher survival rates in fish infected with Streptococcus iniae compared to other dietary groups (P<0.005). This study's outcomes demonstrate that including TYM in the diet of rainbow trout leads to improved fish growth, enhanced immunity, and increased resistance against Streptococcus iniae. see more The research indicates that a 2-25 gram daily TYM intake is the most effective diet for fish.
A substantial regulatory role in glucose and lipid metabolism is played by GIP. GIPR, the receptor of interest, is indispensable to this physiological process. The cloning of the GIPR gene from grass carp was undertaken to ascertain its roles in teleost fish. The cloned gene encoding the glucagon-like peptide-1 receptor (GIPR) exhibited an open reading frame (ORF) of 1560 base pairs, which encoded a protein of 519 amino acids. Within the grass carp, the GIPR G-protein-coupled receptor is predicted to consist of seven transmembrane domains. Among the features of the grass carp GIPR, two predicted glycosylation sites were prominent. Across multiple tissues in grass carp, GIPR expression is observed, with pronounced expression seen within the kidney, brain regions, and visceral fat tissue. The GIPR expression in the kidney, visceral fat, and brain exhibited a considerable decrease after 1 and 3 hours of glucose treatment within the OGTT experiment. The fasting-refeeding protocol showed a pronounced increase in the expression of GIPR in the kidney and visceral fat of the fasting groups. Furthermore, the expression levels of GIPR were significantly reduced in the groups receiving refeeding. The grass carp's visceral fat accumulation was stimulated by overfeeding in the present research. Overfed grass carp demonstrated a considerable decline in GIPR expression within their brain, kidney, and visceral fat tissues. In primary hepatocytes, the presence of oleic acid and insulin resulted in a rise in GIPR expression levels. Treatment with glucose and glucagon resulted in a substantial reduction of GIPR mRNA levels in grass carp primary hepatocytes. see more As far as we can ascertain, this is the initial demonstration of the biological function of GIPR in teleost.
This research examined the effect of dietary rapeseed meal (RM) and hydrolyzable tannins on grass carp (Ctenopharyngodon idella), and explored how tannins might affect fish well-being when mixed with the meal. Eight strategies for dietary management were implemented. T0, T1, T2, and T3 represent four semipurified diets with 0, 0.075, 0.125, and 0.175% hydrolyzable tannin, respectively; these were matched in tannin content by four practical diets (R0, R30, R50, and R70), containing 0, 30, 50, and 70% ruminal matter. The practical and semipurified groups displayed a similar trajectory in antioxidative enzyme activity and associated biochemical measurements after the 56-day feeding trial. Tannin and RM levels' influence on hepatopancreas superoxide dismutase (SOD) and catalase (CAT) activity, respectively, was accompanied by increases in glutathione (GSH) content and glutathione peroxidase (GPx) activity. An increase in malondialdehyde (MDA) was observed in T3, while a decrease was noted in R70. A correlation was observed in the intestine, wherein MDA content and SOD activity augmented with escalating RM and tannin levels, while GSH content and GPx activity exhibited a diminishing trend. With respect to RM and tannin levels, interleukin 8 (IL-8) and interleukin 10 (IL-10) expression increased. In contrast, Kelch-like ECH-associated protein 1 (Keap1) expression rose in T3 while decreasing in R50. A 50% concentration of RM and a 0.75% concentration of tannin caused oxidative stress, harm to hepatic antioxidant capabilities, and intestinal inflammation in grass carp, according to this study. Subsequently, the role of tannin in rapeseed meal cannot be overlooked in the context of aquatic animal diets.
The physical properties of chitosan-coated microdiet (CCD) and its influence on survival, growth, digestive enzyme activity, intestinal development, antioxidant capacity, and inflammatory response in large yellow croaker larvae (initially weighing 381020 mg) were investigated through a 30-day feeding trial. Using the spray drying method, four microdiets, maintaining a constant protein (50%) and lipid (20%) composition, were prepared with differing quantities of chitosan wall material (0%, 3%, 6%, and 9% weight per unit volume of acetic acid). The results indicated a significant 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%). Moreover, the CCD diet exhibited a substantially lower loss rate compared to the uncoated diet. A statistically significant difference (P < 0.005) was observed in the specific growth rate (1352 and 995%/day) and survival rate (1473 and 1258%) of larvae fed a diet containing 0.60% CCD, compared to the control group. Larvae fed a diet incorporating 0.30% CCD demonstrated a substantially greater trypsin activity in their pancreatic segments than the control group, as quantified by a difference of 447 and 305 U/mg protein (P < 0.05). A significant difference (P < 0.05) in leucine aminopeptidase (729 and 477 mU/mg protein) and alkaline phosphatase (8337 and 4609 U/mg protein) activity was observed in the brush border membrane of larvae fed a diet containing 0.60% CCD, compared to the control group.