5282
Marwa Mamdouh Mohamed Tawfik
Evaluation of Zinc Oxide Nanoparticles Effect on Fish Growth and Immunity
Zinc Oxide Nanoparticles, Nanotechnology, Interleukin 1-beta Gene Expression, Growth, Oreochromis niloticus.
The incidence of diseases and mortalities in aquaculture and development of antibiotics resistance in aquatic microbes increased a great interest to alternative methods of prevention and control of diseases, especially that aquaculture is the last frontier to solve the problem of the global deficiency of white protein. Some studies reported that, nano-particles have enormous potential in controlling the pathogens in aquaculture. Some metal and metal oxide nano-particles were screened for their growth promoting, immunity stimulating and antimicrobial activities in aquaculture. The present investigation was carried out to evaluate nano-ZnO (nZnO) in comparison to its conventional form as a fish feed additive in growth promoting and immunostimulation of Nile tilapia fish (Oreochromis niloticus; the common cultured fish in Egypt and other countries. Zinc oxide nanoparticles were prepared using the chemical method and mixed with the fish feed. 405 Oreochromis niloticus was fed for 120 days on Zinc oxide conventional bulk scale (ZnO) and nanoscale (nZnO) supplemented feed in different concentrations (15, 30, 45 and 60 mg/kg of the feed) in addition to the control which was fed on ZnO free feed. The experiment was carried out in triplicate in plastic tanks in the hydrobiology wet lab, National Research Centre. Growth performance was evaluated through analysis of weight gain, specific growth rate and growth hormone in blood, nZnO (15mg/kg) achieved specific growth rates like the higher concentrations of bulk ZnO (60mg/kg). The 60mg/kg nZnO gave the highest rates of SGR; 4 folds than control. growth hormone was higher in serum of fish fed on nZnO supplemented feed than the bulk form. Immunity was assessed through the measurement of total protein and IgM titer and IL1-beta (IL-1β) gene expression. Total protein and IgM titers revealed high values increasing with the increase of concentration of ZnO feed additive in its two forms compared to the control, but nZnO showed better results than conventional ZnO. Regarding the analysis of IL1-beta gene expression, 60mg/kg conventional ZnO was the best concentration for up-regulating the IL1-beta followed by the concentration 30mg/kg in the two forms; the nano and the conventional form. The inorganic conventional ZnO up-regulated the IL-1β better than the nZnO form, thus from the economic point of view using of nZnO will not be efficient as immuno-stimulant. Zinc was concentrated higher in muscles of fish fed on nZnO supplemented feed more than the fish fed on conventional ZnO supplemented feed due to its availability building on its small size but still within the permissible limits. One wayANOVA statistical analysis was used in all analyses with p<0.05.
2017
M.Sc
Cairo
Veterinary Medicine