Search

Most probiotic yeast supplement in fish exhibit beneficial effect at ≤1% of the dietary proportion. This study aimed at evaluating the specific effects of Lypomyces starkeyi CB1807 yeast strain supplemented at ≤1% of dietary proportion on the performance of juvenile red sea bream (Pagrus major, 1.9 ± 0.04 g). Five diets were supplemented with yeast at graded levels of 0% (control diet ‘CD1’), 0.05% (D2), 0.1% (D3), 0.5% (D4), and 1.0% (D5). After 45 days of feeding trial, significant (P<0.05) improvement was detected on final body weight (FBW) and body weight gain (BWG) in fish fed D3 and D5 compared to control. Low values of total cholesterol (T-Cho) and aspartate aminotransferase (AST) were recorded in fish groups fed on D2, D4, and D5, respectively. Fish fed on D3, D4 and D5 diets showed high (P<0.05) values of serum, mucus and liver lysozyme compared to control. Fish fed on D5 showed high values of total immunoglobulin (Ig) compared to control. Fish fed on D2 showed strong correlation with biological antioxidant activity (BAP), superoxide dismutase (SOD) and catalase activity (CAT). The biological antioxidant potential (BAP) activity in fish fed on D2 was significantly higher compared to control (P<0.05). The reactive oxygen metabolites (d-ROM) were significantly lower in fish fed on D2 and D3 compared to CD1 (P<0.05). Peroxidase activity was improved significantly (P<0.05) in fish fed on D3, D4 and D5 compared to control. The tolerance ability (LT50) of fish fed on D5 against low salinity stress was significantly higher compared to control (P<0.05). It was concluded that dietary benefits of spent L. starkeyiyeast at ≤1% showed considerable improvement in antioxidant capacity in red sea bream, P. major.

The aim of this experiment was to assess the potential benefits of supplementing coenzyme Q10(CoQ10) in the diet of Liza ramada, with a focus on growth promotion, enhanced feed utilization, improved digestive enzyme activity, bolstered antioxidant defenses, and overall health. Five diets were prepared, maintaining consistent levels of lipids (7%) and protein (32%). These diets featured equivalent raw materials but varied in their CoQ10content (0, 20, 40, 60, and 80 mg CoQ10/kg diet). Initial fish weight averaged 90.89±0.41 g, and each diet was administered to fish in triplicate tanks over a 60-day feeding period. Surprisingly, the diet with 80 mg/kg of CoQ10 showed the most substantial increases in weight gain (131.23±1.82 g), specific growth rate (1.40±0.01%/day), and a more favorable feed conversion ratio (1.73±0.01), outperforming the 60, 40, and 20 mg/kg CoQ10 diets. Additionally, 40 and 60 mg/kg CoQ10diets demonstrated substantial improvements in digestive enzyme activity [protease (22.30±0.80 and 21.34±0.77, U/ mg), amylase (19.90±0.65 and 20.15±0.43, U/ mg), and lipase (27.04±0.80 and 27.41±0.87, U/ mg)], antioxidant markers [superoxide dismutase (14.01±0.27 and 14.44±0.62, U/ mg), catalase (1.19±0.04 and 1.20±0.04, U/ mg), and glutathione peroxidase (3.27±0.14 and 3.47±0.16, U/ mg)], and immune responses [lysozyme (302.12±3.18 and 294.25±7.64, U/ ml), bactericidal activity (5.00±0.04 and 6.03±0.14, U/ ml), respiratory burst using nitroblue tetrazolium (0.55±0.01 and 0.55±0.01, U/ ml), and alternative complement pathway activities (58.29±1.01 and 58.74±0.80, U/ ml)] in L. ramada(p< 0.05). Histological evaluations of the liver and intestine indicated structural enhancements, particularly in the 60 and 80 mg/kg CoQ10groups, suggesting potential benefits for organ health. CoQ10supplementation did not affect the survival rate and biochemical parameters [albumin, glucose, total protein, globulin, total cholesterol, triglyceride, AST, ALT, urea, and creatinine] (p> 0.05). These findings underscore the potential of CoQ10as a valuable dietary additive to enhance the growth and overall health of L. ramada, with recommended inclusion levels of CoQ10falling between 60 and 80 mg/kg.

The beneficial effects of Bacillus subtilisC-3102 and Saccharomyces cerevisiaetype 1 were tested in red sea bream (Pagrus major) feeds. A basal diet (control) and two other diets were prepared by supplementation with B. subtilisC-3102 (PB) or S. cerevisiaetype 1 (PY). After 60 days, both probiotic-supplemented groups exhibited significant enhancement in growth performance, the protein efficiency ratio (PER), and digestive enzyme secretion (protease and amylase) compared to the control group (P<0.05). The anterior, middle, and posterior parts of the intestines exhibited significantly increased values of intestinal fold height (hF), enterocyte height (hE), and microvillus height (hMV) in fish fed PB- or PY-supplemented diets (P<0.05). Serum peroxidase, anti-protease, and bactericidal activities were enhanced significantly in both probiotic-treated groups compared to the control group (P<0.05). Serum and mucus lysozyme activities improved significantly in the PB group compared to the control group (P<0.05). Catalase activity was also significantly decreased in both probiotic groups, with relatively lower activity observed in the PY group (P<0.05). Both probiotic groups showed considerably increased tolerance to freshwater exposure (P<0.05). In conclusion, B. subtilisC-3102 and S. cerevisiaetype 1 can be used as functional probiotics to enhance the growth performance, digestion capacity, gut morphology, immune response, and stress resistance of the red sea bream with relatively higher efficiency by B. subtilisC-3102.