Diets containing three experimental feed types, a control diet (Control, crude protein (CP) 5452%, crude lipid (CL) 1145%), a low-protein diet including lysophospholipid (LP-Ly, CP 5246%, CL 1136%), and a low-lipid diet with lysophospholipid (LL-Ly, CP 5443%, CL 1019%), were given to the largemouth bass (Micropterus salmoides). A 1g/kg addition of lysophospholipids was signified by the LP-Ly group in the low-protein group and the LL-Ly group in the low-lipid group, respectively. The 64-day feeding experiment yielded no substantial variations in growth performance, hepatosomatic index, and viscerosomatic index for largemouth bass in the LP-Ly and LL-Ly groups when contrasted with the Control group, with a P-value exceeding 0.05. Whole fish from the LP-Ly group displayed a significantly greater condition factor and CP content than those in the Control group (P < 0.05). The serum total cholesterol levels and alanine aminotransferase enzyme activities were substantially lower in both the LP-Ly and LL-Ly groups, when compared to the Control group (P<0.005). Liver and intestinal protease and lipase activities were substantially greater in the LL-Ly and LP-Ly groups compared to the Control group (P < 0.005). A substantial reduction in liver enzyme activities and gene expression of fatty acid synthase, hormone-sensitive lipase, and carnitine palmitoyltransferase 1 was observed in the Control group in comparison to both the LL-Ly and LP-Ly groups, a difference statistically significant (P < 0.005). Lysophospholipid supplementation led to an increase in the number of advantageous bacteria, specifically Cetobacterium and Acinetobacter, and a decrease in the number of detrimental bacteria, like Mycoplasma, within the gut's microbial community. In closing, lysophospholipid supplementation in low-protein or low-lipid diets did not hinder largemouth bass growth, but rather activated intestinal digestive enzymes, boosted hepatic lipid processing, stimulated protein accumulation, and modified the composition and diversity of the intestinal microflora.
A surge in fish farming operations correlates with a relative scarcity of fish oil, making it imperative to seek alternative lipid resources. The present study comprehensively examined the potential of poultry oil (PO) as a replacement for fish oil (FO) in the diets of tiger puffer fish (average initial body weight, 1228 grams). An 8-week feeding trial, employing experimental diets, involved graded replacements of fish oil (FO) with plant oil (PO) at 0%, 25%, 50%, 75%, and 100% levels, designated as FO-C, 25PO, 50PO, 75PO, and 100PO, respectively. A flow-through seawater system was employed for the feeding trial. Diets were provided to every one of the triplicate tanks. Tiger puffer growth was not considerably influenced by the substitution of FO with PO, as revealed by the findings. Growth was positively influenced by the partial or complete substitution of FO with PO, ranging from 50% to 100% and even with minimal alterations. PO feeding exhibited a slight impact on fish body composition, with the notable exception of an increase in liver moisture content. BIOPEP-UWM database Dietary intake of PO generally led to a decline in serum cholesterol and malondialdehyde levels, but an elevation in bile acid levels. A rise in dietary PO directly corresponded to an elevated hepatic mRNA expression of 3-hydroxy-3-methylglutaryl-CoA reductase, the cholesterol biosynthesis enzyme. Simultaneously, high dietary PO levels markedly increased the expression of cholesterol 7-alpha-hydroxylase, a crucial regulatory enzyme in bile acid synthesis. Ultimately, poultry oil proves a suitable replacement for fish oil in the diets of tiger puffer. Tiger puffer diets using 100% poultry oil in place of fish oil experienced no adverse effects on growth and body composition.
A 70-day feeding experiment aimed at evaluating the possibility of replacing fishmeal protein with degossypolized cottonseed protein was undertaken on large yellow croaker (Larimichthys crocea) with initial weights ranging between 130.9 and 50 grams. Five diets, with equal nitrogen and lipid contents, were developed. These included 0%, 20%, 40%, 60%, and 80% DCP to replace the fishmeal protein, and correspondingly named FM (control), DCP20, DCP40, DCP60, and DCP80. Statistically significant increases were observed in both weight gain rate (WGR) and specific growth rate (SGR) for the DCP20 group (26391% and 185% d-1) relative to the control group (19479% and 154% d-1), with a p-value less than 0.005. Lastly, fish consuming the 20% DCP diet showed a substantially higher hepatic superoxide dismutase (SOD) activity compared to the control group, a statistically significant difference (P<0.05). The hepatic malondialdehyde (MDA) content was substantially lower in the DCP20, DCP40, and DCP80 groups than in the control group, reaching statistical significance (P < 0.005). Significantly lower intestinal trypsin activity was found in the DCP20 group when compared to the control group (P<0.05). Hepatic proinflammatory cytokine gene transcription (interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-), and interferon-gamma (IFN-γ)) was significantly elevated in the DCP20 and DCP40 groups relative to the control group (P<0.05). The target of rapamycin (TOR) pathway showed a significant increase in the transcription of hepatic target of rapamycin (tor) and ribosomal protein (s6) within the DCP group compared with the control group, in contrast to a significant decrease in the transcription of hepatic eukaryotic translation initiation factor 4E binding protein 1 (4e-bp1) gene (P < 0.005). Based on the results from applying a broken-line regression model to WGR and SGR data against dietary DCP replacement levels, the recommended optimal replacement levels for large yellow croaker are 812% and 937%, respectively. Results from the experiment indicated that the use of 20% DCP in place of FM protein increased digestive enzyme activity, antioxidant capacity, and immune response while activating the TOR pathway, thereby improving the growth performance of juvenile large yellow croaker.
Aquaculture feeds are now increasingly considering macroalgae, a substance showcasing several physiological improvements. The major fish species produced worldwide in recent years is the freshwater Grass carp (Ctenopharyngodon idella). In order to ascertain the suitability of macroalgal wrack in fish feeding practices, juvenile C. idella were given either a standard extruded commercial diet (CD), or this same diet augmented with 7% wind-dried (1mm) powder from a multi-species (CD+MU7) or a single-species (CD+MO7) macroalgal wrack obtained from coastal regions of Gran Canaria, Spain. Following a 100-day feeding period, fish survival rates, weights, and body indices were assessed, and samples of muscle, liver, and digestive tracts were obtained. To ascertain the total antioxidant capacity of macroalgal wracks, the antioxidant defense response and digestive enzyme activity of fish were investigated. Muscle proximate composition, lipid classes, and fatty acid profiles were also the subject of the investigation. The incorporation of macroalgal wracks in the diet of C. idella does not appear to negatively affect growth, proximate and lipid composition, antioxidant capacity, or digestive function, as our results suggest. Positively, macroalgal wracks from both sources diminished general fat storage, and the diverse wrack types strengthened catalase activity within the liver.
We reasoned that the increased liver cholesterol resulting from high-fat diet (HFD) consumption might be countered by the enhanced cholesterol-bile acid flux, which effectively reduces lipid accumulation. This led us to the hypothesis that the enhanced cholesterol-bile acid flux is a physiological adaptation in fish when consuming an HFD. This study examined cholesterol and fatty acid metabolic characteristics in Nile tilapia (Oreochromis niloticus) fed a high-fat diet (13% lipid) for four and eight weeks. Visually healthy Nile tilapia fingerlings, each weighing an average of 350.005 grams, were randomly allocated to four dietary treatments: a 4-week control diet, a 4-week high-fat diet (HFD), an 8-week control diet, or an 8-week high-fat diet (HFD). Following short-term and long-term high-fat diet (HFD) administration, the fish's liver lipid deposition, health condition, cholesterol/bile acid interactions, and fatty acid metabolic functions were scrutinized. blood lipid biomarkers A four-week period of high-fat diet (HFD) ingestion did not affect the activities of serum alanine transaminase (ALT) and aspartate transaminase (AST) enzymes, and liver malondialdehyde (MDA) content remained consistent. In fish maintained on an 8-week high-fat diet (HFD), serum ALT and AST enzyme activities and liver MDA levels were found to be higher. The livers of fish on a 4-week high-fat diet (HFD) displayed an impressive accumulation of total cholesterol, mainly as cholesterol esters (CE). This was further characterized by a subtle increase in free fatty acids (FFAs), and consistent triglyceride (TG) levels. A deeper molecular examination of the liver tissue in fish fed a high-fat diet (HFD) for four weeks revealed a significant buildup of cholesterol esters (CE) and total bile acids (TBAs), primarily due to accelerated cholesterol synthesis, esterification, and bile acid production. Selleck Tin protoporphyrin IX dichloride After four weeks of consuming a high-fat diet (HFD), the fish displayed an increase in the protein expression of acyl-CoA oxidase 1/2 (Acox1 and Acox2). These enzymes are rate-limiting in peroxisomal fatty acid oxidation (FAO), playing a vital part in the conversion of cholesterol into bile acids. Eight weeks of a high-fat diet (HFD) led to a remarkable 17-fold elevation in free fatty acid (FFA) content in fish. Importantly, this increase did not correlate with changes in liver triacylglycerol (TBA) levels. This coincided with suppressed Acox2 protein expression and abnormalities in cholesterol and bile acid biosynthesis. Subsequently, the robust cholesterol-bile acid transport mechanism acts as an adaptive metabolic response in Nile tilapia when fed a brief high-fat diet, potentially through the activation of peroxisomal fatty acid oxidation.