A higher feed conversion ratio coupled with lower retention efficiencies of nitrogen and phosphorus were evident in fish fed diets Se1, Se3, and Se9, contrasting with the fish fed diet Se12. Dietary selenium yeast supplementation, escalating from 1 mg/kg to 9 mg/kg, led to a rise in selenium content within the whole body, vertebrae, and dorsal muscle. Fish nourished by diets Se0, Se1, Se3, and Se9 exhibited less nitrogen and phosphorus waste excretion than those fed diet Se12. The Se3 diet in fish fostered the maximum levels of superoxide dismutase, glutathione peroxidase, and lysozyme activity, and minimized malonaldehyde concentrations in both liver and kidney. Our findings, derived from a nonlinear regression analysis of specific growth rate (SGR), indicated that a dietary selenium requirement of 1234 mg/kg is optimal for triangular bream. The diet containing 824 mg/kg of selenium (Se3) closely matched this optimal level and exhibited superior growth, feed utilization, and antioxidant capacity.
An 8-week feeding trial explored the impact of substituting fishmeal with defatted black soldier fly larvae meal (DBSFLM) in Japanese eel diets, analyzing growth performance, fillet texture, serum biochemical parameters, and intestinal histomorphology. this website Formulating six diets with consistent protein (520gkg-1), fat (80gkg-1), and energy (15MJkg-1) levels, various fishmeal replacement levels were employed: 0% (R0), 15% (R15), 30% (R30), 45% (R45), 60% (R60), and 75% (R75). The parameters of fish growth performance, feed utilization efficiency, survival rate, serum liver function enzymes, antioxidant ability, and lysozyme activity were not influenced (P > 0.005) by the presence of DBSFLM. Nonetheless, the raw protein content and the structural integrity of the fillet in groups R60 and R75 experienced a substantial reduction, while the fillet's firmness exhibited a marked increase (P less than 0.05). Furthermore, the length of intestinal villi experienced a substantial reduction in the R75 group, and the density of goblet cells was notably lower in the R45, R60, and R75 groups, a finding supported by a p-value of less than 0.005. Growth performance and serum biochemical parameters were unaffected by high DBSFLM levels, however, a substantial change in fillet proximate composition, texture, and intestinal histomorphology was quantified (P < 0.05). A 30% substitution of fishmeal, using 184 g/kg DBSFLM, yields optimal results.
Future finfish aquaculture prosperity relies on the continuing improvements in fish diets, which provide the necessary energy for healthy growth and condition of the fish. Strategies to effectively translate dietary energy and protein into fish growth are significantly desired by fish cultivation specialists. By including prebiotic compounds in their diets, humans, animals, and fish can cultivate beneficial gut bacteria. This research project is focused on identifying inexpensive prebiotic substances that effectively boost nutrient absorption from food in fish. The prebiotic effectiveness of multiple oligosaccharide types was researched using Nile tilapia (Oreochromis niloticus), one of the most widely farmed fish species internationally. Dietary impacts on various fish parameters were assessed, including feed conversion ratios (FCRs), the activity of enzymes, the expression of genes related to growth, and the gut microbiome composition. Two groups of fish, 30 and 90 days old respectively, were included in the current study. The inclusion of xylooligosaccharide (XOS), galactooligosaccharide (GOS), or a combined XOS and GOS supplement in the fundamental fish diet led to a substantial reduction in the feed conversion ratio (FCR) across both age cohorts. The feed conversion ratio (FCR) of 30-day-old fish fed XOS and GOS diets was found to be 344% lower than that of the control group. Among 90-day-old fish, the treatment with XOS and GOS reduced feed conversion ratio (FCR) by 119%. The combined prebiotic therapy led to a 202% reduction in FCR, compared to the baseline control group. this website Fish exhibited enhanced antioxidant processes, as indicated by the elevated production of glutathione-related enzymes and the enzymatic activity of glutathione peroxidase (GPX), following XOS and GOS administration. The fish gut microbiota experienced substantial shifts in response to these advancements. XOS and GOS supplementation brought about an upregulation in the abundance of Clostridium ruminantium, Brevinema andersonii, Shewanella amazonensis, Reyranella massiliensis, and Chitinilyticum aquatile. this website Applying prebiotics to younger fish, as suggested by the findings of this study, could yield improved results, and the administration of multiple oligosaccharide prebiotics may lead to a more substantial increase in growth. Potentially utilizing identified bacteria as future probiotic supplements may improve tilapia growth, feeding efficiency, and, subsequently, reduce the overall cost of tilapia aquaculture.
This research seeks to determine the consequences of stocking density variations and dietary protein content adjustments in biofloc aquaculture on the performance of common carp. Fish (1209.099 grams each) were relocated to 15 tanks, where they were raised. Half of the fish were maintained at a medium density of 10 kg/m³, receiving either a 35% or a 25% protein diet (MD35 and MD25, respectively). The remaining fish were raised at a high density of 20 kg/m³, consuming either a 35% or 25% protein diet (HD35 and HD25, respectively). A control group of fish was maintained at medium density in clear water and fed a 35% protein diet. The 60-day period of observation concluded with a 24-hour application of crowding stress (80 kg/m3) to the fish. In MD35, fish growth reached its peak. The MD35 group's feed conversion ratio was inferior to that of the control and HD groups. The biofloc groups demonstrated significantly higher enzymatic activities for amylase, lipase, protease, superoxide dismutase, and glutathione peroxidase relative to the control. Biofloc treatments, following periods of crowding stress, exhibited a substantial reduction in cortisol and glucose levels compared to the control group. Following 12 and 24-hour periods of stress, lysozyme activity exhibited a significantly diminished level in MD35 cells compared to the HD treatment group. With the biofloc system's integration with MD technology, a noteworthy improvement in fish growth and robustness to acute stress may occur. Juvenile common carp raised in MD conditions can achieve similar results despite a 10% decrease in protein in their diet when supported by the biofloc system.
An investigation into the appropriate feeding regimen for tilapia fingerlings is undertaken in this study. The 240 fishes were randomly apportioned into 24 separate containers. Six distinct feeding frequencies—4 (F4), 5 (F5), 6 (F6), 7 (F7), 8 (F8), and 9 (F9)—were employed each day for feeding. The weight gain in groups F5 and F6 was significantly higher than that in group F4, as evidenced by p-values of 0.00409 and 0.00306 for F5 and F6, respectively. No significant divergence in feed consumption or apparent feed conversion was found among the various treatments (p = 0.129 and p = 0.451). Regarding water quality parameters, the nitrogen content in water samples from treatment F4 showed variations when compared to treatment F5 (p = 0.00478), treatment F6 (p = 0.00283), treatment F9 (p = 0.00432), and parameter P compared to F6 (p = 0.00215). A significant dependence (p < 2.2 x 10⁻¹⁷) was observed by the x² test between feed frequencies and the frequency of muscle fibers, with fibers 10-20 micrometers in diameter prevalent in F4, F5, F6, and F7, and fibers 30-40 micrometers in diameter prevalent 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). In summary, the feeding of fingerlings five to six times a day leads to improved zootechnical and partial culinary approaches.
The current research delves into how dietary Tenebrio molitor (TM) larval meal inclusion affects cytoprotective mechanisms, cellular death regulation, antioxidant systems, and intermediate metabolism in the heart, muscle, and digestive tract of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax). A study involving three experimental diets was carried out, using three different TM inclusion levels of 0%, 25%, or 50% respectively. At 50% inclusion, a clear induction of Heat Shock Proteins (HSPs) was observed in the muscle tissue of both species. Differently, p44/42 Mitogen-Activated Protein Kinase (MAPK) activation increased (p < 0.05) in both species' muscle and digestive tissues at the 25% inclusion level. With regard to the machinery of apoptosis, TM inclusion demonstrated no influence on gilthead seabream, however, potential autophagy suppression was seen in the muscle. European sea bass muscle and digestive tracts displayed a substantial level of apoptosis (p < 0.05), as established by statistical analysis. In contrast to their muscle and digestive tract tissues, both fish species' hearts appeared to be significantly reliant on lipids for their energy needs. European sea bass demonstrated heightened antioxidant activity (p<0.05) when the diet contained 50% of TM, in contrast to the antioxidant activity displayed by gilthead sea bream. 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.
The effects of thymol (TYM), administered at dietary levels of 0, 1, 15, 2, and 25g/kg, on growth, digestive function, immunity, and resistance to Streptococcus iniae infection were investigated in rainbow trout, Oncorhynchus mykiss, in this study. Fish, totaling 450 (with an average weight of 358.44g ± standard deviation), were distributed evenly into 15 tanks, each holding 30 fish. The fish were fed TYM for a period of 60 days in three independent trials. In the period after feeding, fish receiving 15-25g TYM exhibited superior growth, greater digestive enzyme activity, and a larger proportion of body protein compared to the other diet groups (P < 0.005).