The effects singular or combined administration of fermentable fiber and probiotic on mucosal immune parameters, digestive enzyme activity, gut microbiota and growth performance of Caspian white fish (Rutilus frisii kutum) fingerlings.

The aim of the present study was to investigate the effects of single or combined administration of dietary fermentable fiber (Vitacel®) and probiotic PrimaLac® on mucosal immune parameters, digestive enzyme activity, gut microbiota and growth performance of Caspian white fish (Rutilus frisii kutum) fingerlings. Fish were transferred to laboratory, acclimatized for two weeks and then fish (0.56 ±â€¯0.026 g) were allocated into 12 tanks (30 fish per tank). Triplicate groups were fed a basal diet (Control) or basal diet supplemented with fermentable fiber [Vitacel®] (FF), probiotic [PrimaLac®] (P) and combined fermentable fiber and probiotic (FF + P). At the end of feeding trial, growth performance and feed utilization parameters were significantly (P < 0.05) improved in FF, P and FF + P treatments compared control group. Evaluation of digestive enzyme activity revealed significant (P < 0.05) increase of lipase activity in fish fed supplemented diet. However, amylase, protease and alkaline phosphatase were significantly higher (P < 0.05) only in P and FF + P treatments. Furthermore, total autochthonous intestinal microbiota and autochthonous LAB levels significantly increased in fish fed supplemented diet (P < 0.05). Also, inclusion of FF, P and FF + P in Caspian white fish diet remarkably increased skin mucus immune parameters compared control group (P < 0.05). These results indicate that singular or combined administration of FF and P can be considered as a beneficial dietary supplement for early stages of Caspian white fish (Rutilus fresii kutumn) culture.

Effects of chronic high stocking density on liver proteome of rainbow trout (Oncorhynchus mykiss).

The main aim of the present study was to assess the effects of chronic high stocking density on liver proteome of rainbow trout. Rainbow trout juveniles (42.6 ± 2.3 g average body weight) were randomly distributed into six tanks at two stocking densities (low stocking density (LD) = 20 kg m-3 and high stocking density (HD) = 80 kg m-3). Both treatments were performed in triplicate tanks for a period of 60 days. High stocking density caused a reduction in the growth performance compared with LD fish. Lysozyme activity increased with stocking density, while serum complement activity presented the opposite pattern. Serum cortisol and total protein levels did not show significant differences (P > 0.05) between experimental groups. The fish reared at high stocking density showed significantly lower osmolality and globulin values but higher albumin level. The HD group had significantly higher activities of catalase, glutathione peroxidase and superoxide dismutase, and malondialdehyde content in the liver when compared to the LD group. Comparative proteomics was used to determine the proteomic responses in livers of rainbow trout reared at high stocking density for 60 days. Out of nine protein spots showing altered abundance (>1.5-folds, P < 0.05), eight spots were successfully identified. Two proteins including apolipoprotein A-I-2 precursor and mitochondrial stress-70 protein were found to increase in HD group. The spots found to decrease in the HD group were identified as follows: 2-peptidylprolyl isomerase A, two isoforms of glyceraldehydes-3-phosphate dehydrogenase, an unnamed protein product similar to fructose-bisphosphate aldolase, 78 kDa glucose-regulated protein, and serum albumin 1 protein.

Proteomic analysis of liver tissue from rainbow trout (Oncorhynchus mykiss) under high rearing density after administration of dietary vitamin E and selenium nanoparticles.

The aim of the present study was to investigate the effects of dietary vitamin E (vit E) and selenium nanoparticles (nanoSe) on liver proteome profile of rainbow trout under high density condition. To correlate the proteome modifications with physiological aspects, growth, serum metabolites (cortisol, glucose, lactate, ALT, AST, and ALP), and liver antioxidant-related parameters (SOD, GPx, CAT, and MDA) were also examined. A total of 1275 fish (average weight of 42.6±2.3g) were stocked into 12 tanks at a density of 80kgm-3. The fish were divided into four groups according to diet: control (basal diet), vit E (500mgkg-1 vit E-supplemented diet), nanoSe (1mgkg-1 nanoSe-supplemented diet), and combination (500mgkg-1 vit E and 1mgkg-1 nanoSe-supplemented diet). After 60days, the best performance and health status of fish were observed in vit E and combination groups. Supplementation with nanoSe had no significant effects on growth performance. In addition, we compared liver proteome profiles of fish fed with a basal diet (control) and diets supplemented with vit E or nanoSe. Among the identified proteins, GRP78, ATPsyn-d, and HSP70 had an increased abundance in the vit E group, while HPPD and GAPDH showed a decreased abundance. In response to nanoSe supplementation, the expression of MDH, FAA, FBPA, TPI, GRHPR, GNMT, FDH, and Enol was increased. The proteomic data indicate that vit E or nanoSe supplementation can alter the expression of proteins involved in metabolic status of rainbow trout reared under high rearing density.