Title: EFFECTS OF DIETARY ZINC ON GROWTH,IMMUNE RESPONSE AND TISSUE CONCENTRATION OF JUVENILE JAPANESE SEABASS LATEOLABRAX JAPONICUS
Abstract: An experiment was conducted to study the effects of dietary zinc on growth(weight gain,feed efficiency ratio,specific growth rate and survival rate),immune response(lysozyme activity and total complement activity) and body distribution of zinc concentration of juvenile Japanese seabass Lateolabrax japonicus.Five iso-nitrogenous and iso-ener-getic diets were formulated and contained 83.3,95.2,101.6,120.3,159.9mg zinc per kg diet,supplied as ZnSO4·H2O,and fed in 15 floating netcages(1.5×1.0×1.0m3) with 20 fish [initial weight:(10.0±0.58)g];fish were fed twice daily(09:30 and 16:30) for 8 weeks,the water temperature fluctuated from 26.5℃ to 32.5℃,salinity from 28 to 29 and dissolved oxygen was approximately 6mg/L during the experimental period.Results indicate that no significant differences in sur-vival rate(95.00%—100.00%) were found among dietary treatments(P0.05).The weight gain rate and specific growth rate increased significantly with increasing dietary zinc from 83.3 to 101.6mg/kg(P0.05),but no significant differences were observed among the fish fed the diets with equal to or higher than 101.6mg/kg of zinc(P0.05),and the optimal die-tary zinc content for maximum growth was about 103.4mg/kg.No significant differences in zinc concentration of muscle were found among dietary treatments(P0.05),zinc concentration in liver increased significantly with increasing dietary zinc from 83.3 to 101.6mg/kg(P0.05);no significant differences were observed among the fish fed the diets with equal to or higher than 101.6mg/kg of zinc(P0.05),juvenile Japanese seabass maintained greatest zinc concentration in liver and lowest zinc demand content when fed with 105.1mg/kg of dietary zinc.Serum lysozyme activity and total complement activity of juvenile Japanese seabass increased significantly with increasing dietary zinc from 83.3 to 101.6mg/kg(P0.05),but no significant differences were observed among the fish fed with the diets with equal to or higher than 101.6mg/kg of zinc(P0.05).Based on the information above,the optimal dietary zinc content for optimum growth performance and immune response in juvenile Japanese seabass was about 105.1mg/kg of dietary zinc.
Publication Year: 2009
Publication Date: 2009-01-01
Language: en
Type: article
Access and Citation
Cited By Count: 2
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot