Veterinary Research Forum

Abstract Use of various nanoparticles and vitamins to strengthen the immune system of fish to improve growth and biochemical indice, and to mitigate the harmful effects of free radicals through enhanced antioxidant enzyme activity has become the subject of numerous studies. In this study, fish with an average weight of 55.20 ± 7.90 g, after a two-week acclimation period, were randomly distributed into 18 polyethylene 300-L tanks, with 25 fish per tank. The experiment consisted of six treatments with three replicates: Control, vitamin (Vit) C100, nano-selenium (N-Se)0.40, Vit C100 + N-Se0.10, Vit C200 + N-Se0.20, and Vit C400 + N-Se0.40. Blood samples were collected post-treatment for analysis of antioxidant enzyme activities, biochemical and hematological indices as well as post-handling stress. Results indicated significant differences in antioxidant enzyme activities among treatments. The highest catalase activity was observed in Vit C100 and Vit C100 + N-Se0.10 groups. Glutathione peroxidase activity was significantly higher in the control and Vit C200 + N-Se0.20 groups. Malondialdehyde was the highest in Vit C100 + N-Se0.10 group. Superoxide dismutase activity peaked in Vit C200 + N-Se0.20 group. Biochemical indices showed significant differences among treatments except for high-density lipoprotein. Hemoglobin and red blood cell counts were significantly different. The Vit C100 + N-Se0.10 group showed the highest serum cortisol and glucose levels post-handling stress. Overall, dietary N-Se and Vit C supplementation improved antioxidant, biochemical, hematological indices and stress resistance in rainbow trout.

Abstract Lecithotrophic larvae utilize extensive yolk reserves for early development. In this study, the effect of egg docosahexaenoic acid (DHA):eicosapentaenoic acid (EPA) ratios (i.e., 5.92, 10.08, 11.66, and 14.53) on the emerging larvae foregut development of rainbow trout was examined. Larvae samples were taken from day 22 to 36 post-fertilization. Thin whole body longitudinal sections were prepared and stained by Hematoxylin and Eosin and Alcian blue procedure. The sections were examined regarding epithelial layer thickness, intestinal fold height and mucosal layer thickness along with number of enterocytes and goblet cells. Results indicated that maximum thickness of the epithelium was observed on day 36 post fertilization in larvae hatched from eggs with DHA:EPA ratios of 14.53 and 10.08. The highest and lowest intestinal folds height were also observed in larvae hatched from eggs with DHA:EPA ratios of 10.08 and 14.53, respectively. The mucosal-submucosa layer thickness was the highest in larvae hatched from eggs with DHA:EPA ratio of 10.08. Enterocyte’s count was the highest in larvae obtained from eggs with DHA:EPA ratio of 10.08 on day 36 post-fertilization. The highest and lowest number of goblet cells were enumerated in larvae obtained from eggs with DHA:EPA ratios of 5.53 and 14.53, respectively. In conclusion, our results revealed that feeding rainbow trout broodstock with diet contained highly unsaturated fatty acids (HUFA):polyunsaturated fatty acids (PUFA) ratio of 0.28 could result in the egg with DHA:EPA ratio of 10.08 which in turn yielded larvae with better foregut development parameters compared to those larvae emerged from the eggs with increased DHA :EPA ratio.

Abstract This research explored the impacts of feed-born silver nanoparticles (AgNPs) on common carp (Cyprinus carpio) and whether dietary curcumin supplementation could ameliorate the impacts of AgNPs on growth, hemato-biochemical parameters and digestive enzyme activity. Nine experimental diets were prepared containing 0.00, 0.05, and 0.15 g kg^-1 AgNPs, as well as 0.00, 0.75, and 1.50 g kg^-1 curcumin in a factorial design. Triplicate groups of common carp (4.82 ± 0.41 g) were fed on the test diets for 60 days. The results demonstrated that AgNPs reduced growth performance and enhanced the feed conversion ratio dose-dependently. Supplementing 0.75 g kg^-1 curcumin at a low AgNP level improved the growth rate, while its inclusion at a high AgNP level led to further suppression of growth performance. The highest hematocrit value, hemoglobin concentration and white blood cell count were recorded in the group receiving 0.75 g kg^-1 curcumin. Serum glucose, cholesterol and triglyceride concentrations were elevated by increasing AgNP levels. However, curcumin inclusion, particularly at the lower level of AgNPs significantly decreased their values. Similarly, intestinal alkaline protease and lipase activities were progressively reduced by increasing dietary AgNP contents, but, significant improvements were observed by curcumin application at the lower AgNP level. Our results revealed that curcumin supplementation could limit the toxic effects of lower dietary AgNP contents.