Modulation of growth performance, feed utilization, and physiological traits in redbelly Tilapia (Tilapia zillii) through environmental and sex-based interactions.

This study explored the combined influence of tank color, stocking density, and gender on Tilapia zillii's performance and well-being. In this 120-day trial, 320 T. zillii, each initially weighing 10.0 ± 0.1 g/fish, were distributed among 24 tanks. The experiment included eight distinct treatment combinations, varying tank color (blue and green), stocking density (10 and 30 fish/m3) and sex (monosexual and mixed). The results showed that blue tanks improved specific growth rate and condition factor, while green tanks were better for feed utilization. Density at 30 fish/m3 showed the highest mean values of final body weight and total length, weight gain (WG), and gain length. Mono-sex outperformed mixed-sex ones in WG and daily growth. Interactions between color, density and sex were significant, affecting growth and feed utilization. Green tanks were best for protein profiles, while blue tanks excelled in glucose. A density of 10 fish/m3 yielded the highest protein profiles, and mono-sex fish had higher protein profiles. For lipid profiles, green tanks were superior, and density affected lipid profiles. Mixed-sex populations were best for certain lipid profile parameters. Interactions between these factors also played a significant role, making the biochemical profiles of T. zillii a complex interplay of various factors. The results explored that tank color, fish density and sex influence the activity of nonspecific immune enzymes in the liver of T. zillii. Blue tanks and lower fish density led to higher nonspecific immune enzymes, while mono-sex fish exhibited more significant nonspecific immune enzymes. Complex interactions between these factors also influenced nonspecific immune enzyme activities. Blue tanks increased malondialdehyde (MDA) levels, while green tanks raised glutathione S-transferases (GST) and catalase (CAT) levels. Lower fish density led to higher MDA, while higher density increased GST and CAT. Mono-sex fish had more MDA and GST, while mixed-sex fish showed greater CAT levels. Complex interactions among these factors affected the antioxidant levels in T. zillii. In summary, our study suggests that rearing T. zillii in green tanks at higher densities (30 fish/m3) and in mono-sex conditions yields the best results in terms of growth and overall performance.

Ginseng, Tribulus Extracts and Pollen Grains Supplementation Improves Sexual State, Testes Redox Status, and Testicular Histology in Nile Tilapia Males.

This study aimed to investigate the effect of dietary supplementation of three natural antioxidants on sex hormone levels, enzymatic and non-enzymatic antioxidant systems, and histological changes in the testes of male Nile tilapia, Oreochromis niloticus. A total of 210 male Nile tilapia were distributed into seven treatments (three replicates for each) with an initial weight of 3.67 g fish-1. The fish were fed experimental diets (32% crude protein) without supplementation as control or supplemented with ginseng extract (GE; 0.2 and 0.4 g GE kg-1 diet), Tribulus terrestris extract (TT; 0.6 and 1.2 g TT kg-1 diet), and date palm pollen grains (DPPG; 3 and 6 g DPPG kg-1 diet) for 84 days. The results revealed a significant increase in the luteinizing hormone level with TT, DPPG, and GE supplementation increased the levels by 22.9%, 18.5%, and 17.6%, respectively. The testosterone level also increased significantly with TT1.2, GE0.4, TT0.6, and DPPG6 by 86.23%, 64.49%, 57.40%, and 24.62%, respectively. The antioxidant status in the testis homogenate showed a significant decrease in the level of thiobarbituric acid-reactive substances when using different dietary substances. In addition, glutathione reduced contents, glutathione S-transferases, glutathione peroxidase, catalase, and superoxide dismutase activities significantly increased with different dietary supplementation in a dose-dependent manner. The histological evaluation revealed normal histological features of the testes in all treatments with increasing active seminiferous tubules (%) in GE, TT, and DPPG supplemented groups, especially with the highest levels. In conclusion, the dietary supplementation of GE, TT, and DPPG enhanced sex hormones level, redox status, and testis structure and could improve the male reproductive performance of Nile tilapia.

The Immunostimulatory Effects of Commercial Feed Additives on Growth Performance, Non-specific Immune Response, Antioxidants Assay, and Intestinal Morphometry of Nile tilapia, Oreochromis niloticus.

The main objective of the present research was to investigate the impacts of commercial immunostimulants on growth, non-specific immune response, antioxidant enzymes, and intestinal morphometry of Nile tilapia, Oreochromis niloticus. Fish (100 ± 6.5 g) were randomly divided into five groups in triplicates (150 fish in each replicate), stocked in 20 m2 of aerated concrete ponds. The fish were fed on a control diet (30.0% crude protein) (control), and four experimental diets supplemented with Yeast Plus®, Digestarom®, and Biotronic® Top3 at 1 kg ton-1, and Sanolife PRO-F® at 0.5 kg ton-1. After the experimental period, the highest significant yield (kg m-3), mean final weight (g fish-1), average weight gain (g fish-1), and specific growth rate (% body weight day-1), were recorded in fish fed on the diet supplemented by Sanolife PRO-F, followed by Yeast Plus ponds. The lowest yield was recorded in the control group. However, the feed conversion ratio was significantly decreased with Sanolife PRO-F diet. Furthermore, the hematological analysis increased in the following ascending order: Sanolife PRO-F®; Yeast Plus®; Biotronic® Top3 and finally Digestarom® groups. The lowest concentrations of white blood cells, red blood cells, hematocrite, and hemoglobin (P ≤ 0.05) were observed in the control group. The levels of phagocytic activity and phagocytic index were significantly higher in fish fed with Sanolife PRO-F® group (P ≤ 0.05). Likewise, serum lysozyme activity was significantly highest in Sanolife PRO-F (0.63 and 0.68 U/mL, after 0.5 min and 3 min, respectively). Levels of total serum proteins, globulin, Immunoglobulin M, catalase, and super oxide dismutase were significantly higher in fish fed with Sanolife PRO-F® supplement. On the contrary, length measurement of the intestinal villus height/width, absorption area, crypt depth, and goblet cells, were significantly lower in the control group, whereas their highest values was observed in fish fed Sanolife PRO-F (P ≤ 0.05). Consequently, Sanolife PRO-F® is recommended at a level of 0.5 kg ton-1, to improve the growth performance, antioxidative capacity, and immune response of Nile tilapia.

Dietary supplementation of organic selenium improves growth, survival, antioxidant and immune status of meagre, Argyrosomus regius, juveniles.

Oxidative stress is considered one of the main obstacles to immune competence and high mortality rate of marine fish larvae due to the high dietary polyunsaturated fatty acids and accelerated metabolic rate. This study was carried out to assess the effect of different dietary selenium (Se) yeast on growth, antioxidant status, hematological changes, and cellular and humoral immune parameters in meagre (Argyrosomus regius). Juvenile specimens (3.20 ± 0.17 g) were randomly assigned to four experimental groups, a control group fed a basal diet and another three groups fed Se-supplemented diets at doses of 1, 2 and 3 mg Se-yeast kg-1 diet for 63 days and the final analyzed selenium concentrations were 0.77, 1.51, 2.97 and 3.98 mg Se kg-1 diet, respectively. The results indicated that growth performance, feed conversion ratio and survival were significantly improved with 2.97 and 3.98 mg Se-yeast kg-1 compared to the control group. The catalase, superoxide dismutase activities and total antioxidant status were significantly increased, and thiobarbituric reactive substances in liver homogenate were significantly decreased with increasing Se supplementation respect to the control fish in a dose-dependent manner. Furthermore, hematological and innate immune parameters (immunoglobulin, lysozyme, myeloperoxidase, ACH50 and respiratory burst activity) were also significantly higher in fish fed the Se-yeast supplemented diets compared to the control group. The results demonstrated that the supplementation of 3.98 mg Se-yeast kg-1 diet improves growth performance, antioxidant balance and innate immune status of meagre juveniles.