Zinc Oxide, Zinc Sulfate and Zinc Oxide Nanoparticles as Source of Dietary Zinc: Comparative Effects on Growth and Hematological Indices of Juvenile Grass Carp (Ctenopharyngodon idella)

To compare the effect of different dietary inorganic sources of zinc (Zn) i.e., zinc oxide (ZnO), zinc sulfate (ZnSO4) and zinc oxide nanoparticles (ZnO-NP) on growth performance and some hematological indices of juvenile grass carp, Ctenopharyngodon idella, a 90 day feeding experiment under laboratory condition was executed. Six 35% protein experimental diets supplemented with dietary Zn in zinc oxide nanoparticles (ZnO-NP-I, ZnO-NP-II), oxide (ZnO-I, ZnO-II) and sulfated (ZnSO4-I and ZnSO4-II) forms at two levels, 30 and 60 mg kg(-1) diet each and seventh basal diet (C) without supplementation were fed to triplicate groups of fish. Significantly higher (P < 0.05) percentage weight gain (% WG), specific growth rate (SGR) and feed conversion ratio (FCR) was observed in group of fish fed ZnO-NP-Idiet followed by ZnO-NP-II diet. However, retarded growth was observed in response to diets enriched with sulfated form of Zn at both levels and ZnO at higher level. Moreover, dietary Zn supplementation in oxide and sulfate forms at both concentration and nanoparticle form at higher concentration significantly decreased (P < 0.05) the values of hematological parameters, while, ZnO-NP at the rate of 30 mg kg(-1) diet significantly increased the red blood cells (RBCs) count and mean corpuscular hemoglobin concentration (MCHC) value. These results clearly indicated that dietary Zn supplementation in the nanoparticles form improved the growth performance and RBCs count of juvenile grass carp, C. idella as compare to oxide and sulfated form of Zn. (C) 2015 Friends Science Publishers