Chitosan (CH) shows great potential as an immunostimulatory feed additive in aquaculture. This study evaluates the effects of varying dietary CH levels on the growth, immunity, intestinal morphology, and antioxidant status of Nile tilapia (Oreochromis niloticus) reared in a biofloc system. Tilapia fingerlings (mean weight 13.54 ± 0.05 g) were fed diets supplemented with 0 (CH0), 5 (CH5), 10 (CH10), 20 (CH20), and 40 (CH40) mL·kg⁻¹ of CH for 8 weeks. Parameters were assessed after 4 and 8 weeks. Their final weight was not affected by CH supplementation, but CH at 10 mL·kg⁻¹ significantly improved weight gain (WG) and specific growth rate (SGR) compared to the control (p < 0.05) at 8 weeks. Skin mucus lysozyme and peroxidase activities were lower in the chitosan-treated groups at weeks 4 and 8. Intestinal villi length and width were enhanced by 10 and 20 mL·kg⁻¹ CH compared to the control. However, 40 mL·kg⁻¹ CH caused detrimental impacts on the villi and muscular layer. CH supplementation, especially 5–10 mL·kg⁻¹, increased liver and intestinal expressions of interleukin 1 (IL-1), interleukin 8 (IL-8), LPS-binding protein (LBP), glutathione reductase (GSR), glutathione peroxidase (GPX), and glutathione S-transferase (GST-α) compared to the control group. Overall, dietary CH at 10 mL·kg⁻¹ can effectively promote growth, intestinal morphology, innate immunity, and antioxidant capacity in Nile tilapia fingerlings reared in biofloc systems.

Bacillus sp. THPS1 is a novel strain isolated from a high-temperature hot spring in Thailand, exhibiting distinctive genomic features that enable adaptation to an extreme environment. This study aimed to characterize the genomic and functional attributes of Bacillus sp. THPS1 to understand its adaptation strategies and evaluate its potential for biotechnological applications. The draft genome is 5.38 Mbp with a GC content of 35.67%, encoding 5606 genes, including those linked to stress response and sporulation, which are essential for survival in high-temperature conditions. Phylogenetic analysis and average nucleotide identity (ANI) values confirmed its classification as a distinct species within the Bacillus genus. Pangenome analysis involving 19 others closely related thermophilic Bacillus species identified 1888 singleton genes associated with heat resistance, sporulation, and specialized metabolism, suggesting adaptation to nutrient-deficient, high-temperature environments. Genomic analysis revealed 12 biosynthetic gene clusters (BGCs), including those for polyketides and non-ribosomal peptides, highlighting its potential for synthesizing secondary metabolites that may facilitate its adaptation. Additionally, the presence of three Siphoviridae phage regions and 96 mobile genetic elements (MGEs) suggests significant genomic plasticity, whereas the existence of five CRISPR arrays implies an advanced defense mechanism against phage infections, contributing to genomic stability. The distinctive genomic features and functional capacities of Bacillus sp. THPS1 make it a promising candidate for biotechnological applications, particularly in the production of heat-stable enzymes and the development of resilient bioformulations.

Feeding low crude protein (LCP) diets supplemented with crystalline amino acids improves environmental and welfare parameters of broilers. However, increased body fat contents in broilers fed LCP diets have become a concern. Black soldier fly larvae oil (BSFLO), rich in lauric acid, has been reported to inhibit lipogenesis and reduce body fat. A 3 × 2 factorial experiment was conducted to evaluate the effect of BSFLO on performance, blood biochemistry, carcass quality, fat metabolism gene expression, and litter quality in broilers fed protein-reduced diets. A total of 288 broilers were divided into 6 treatments: three CP levels (200, 185, or 170 g/kg; high [HCP], medium [MCP], or low [LCP]) and two oil sources (BSFLO and Crude Palm Oil [CPO]), with 6 replicate pens of 8 birds each. Results showed a 15 g/kg CP reduction had no effect on body weight and feed intake (P > 0.05) but increased FCR (P = 0.001). A 30 g/kg CP significantly reduced the body weight and feed intake with inferior FCR (P < 0.05). However, negative effect of low CP diets on FCR was mitigated by BSFLO (P = 0.008). Reducing CP by 30 g/kg increased fat pads (P = 0.033), whereas BSFLO reduced fat pads (P = 0.049) at all three CP levels. Protein-reduced diets increased blood cholesterol (P = 0.002), HDL (P < 0.001), and LDL (P = 0.002). BSFLO decreased blood triglyceride (P = 0.026) and cholesterol (P < 0.001). Reducing 30 g/kg CP increased meat cooking loss (P = 0.035), while BSFLO decreased cooking loss (P < 0.001). BSFLO increased meat protein (P < 0.001) and decreased cholesterol (P = 0.003). The inclusion of BSFLO in protein-reduced diet down-regulated the gene expression of FAS, ACC, SREBP-1, and HMGR in broilers (P < 0.001). Reducing CP levels decreased litter pH (P = 0.011), nitrogen (P < 0.001), ammonia (P < 0.001) and moisture (P = 0.018). The study concludes that BSFLO reduced body fat by down-regulating the lipogenesis gene expression. In addition, BSFLO enhanced feed efficiency in broilers fed protein-reduced diet.

This study investigated the individual and combined effects of SFO and LP supplementation on growth performance, carcass traits, meat quality, fatty acid profile, and serum biochemical indices in crossbred (Boer × Saanen) buck goats. Twenty-eight bucks (4 months old; 18.42 ± 2.03 kg) were randomly assigned to four treatments (n = 7): control, SFO (5–10 mL/day), LP (10 mL containing 10⁷ CFU/goat on alternate days), and SFO+LP. Growth performance was not affected; however, the feed conversion ratio (FCR) improved significantly (p < 0.001) in supplemented groups, with improved efficiency observed in SFO+LP, indicating enhanced feed utilization efficiency despite differences in feed intake. Carcass traits were unchanged. Meat quality improved in SFO and SFO+LP groups, as evidenced by lower pH at 45 min postmortem (p = 0.045) and reduced Warner–Bratzler shear force (p = 0.036), indicating enhanced tenderness. The combined SFO+LP treatment significantly increased C18:2 n6t (p = 0.036), total CLA (p = 0.003), and total PUFA (p = 0.001), indicating improved nutritional value of the lipids. Significant treatment × time interactions (p < 0.05) were observed for lipid and enzyme parameters, with values increasing over time in the supplemented groups, while glucose remained unchanged. These results indicate a synergistic interaction between SFO and LP, likely through modulation of rumen biohydrogenation and lipid metabolism, enhancing feed efficiency and meat functional quality without compromising metabolic health.

Diabetic nephropathy (DN) is a major complication of chronic hyperglycemia. Although fish gelatin hydrolysate has antioxidant, anti-inflammatory, and antihypertensive properties, its renoprotective effects in DN remain unclear. This study investigated its effects on renal oxidative stress, inflammation, fibrosis, and endoplasmic reticulum (ER) stress in diabetic rats. Thirty male Wistar rats were fed a normal chow diet or a high-fat diet for 4 weeks. Diabetes was induced in high-fat-diet-fed rats by a single intraperitoneal injection of streptozotocin (30 mg/kg). Diabetic rats were randomly assigned to receive no treatment (untreated diabetes), gelatin hydrolysate at 250 or 500 mg/day, or metformin at 100 mg/kg/day groups (n = 6/group), while normal-chow-fed rats served as controls. Treatments were orally administered for 8 weeks. High-dose gelatin hydrolysate improved metabolic disturbances and renal dysfunction, whereas low-dose gelatin hydrolysate and metformin more effectively reduced oxidative stress, as indicated by decreased 8-OHdG expression. All treatments reduced renal injury, fibrosis, and inflammatory markers. ER stress-related proteins were also attenuated, with the greatest changes observed in IRE1/XBP1-associated markers. These findings provide in vivo evidence that GLH treatment is associated with improved renal outcomes and reduced markers of oxidative stress, inflammation, fibrosis, and ER stress in DM rats.