Effect Of The Environmental Friendly Additives On The Growth Performance,Digestive Enzyme Activities And Serum Non-specific Immunity Of Lateolabrax Japonicus

To evaluate the effect of the simple and combined additives on growth performance,digestive enzyme activities and serum non-specific immunity of Lateolabrax japonicus.Two kinds of simple additive were discusses in the study:one was Mannan oligosaccharide,the other one was fermented Enteromorpha prolifera.Combined additives containing fermented Enteromorpha prolifera,Enteromorpha ultrafine powders and Chinese herbal medicine.The results were as follows:(1)Effect of simple additive on growth performance,digestive enzyme activities and serum non-specific immunity of Lateolabrax japonicus.?.Effect of different levels of Mannan-oligosaccharide on growth performance,digestive enzyme activities and serum non-specific immunity of Lateolabrax japonicus.Adding 6 diets 0%,0.1%,0.2%,0.3%,0.4%,0.5%Mannan-oligosaccharide were respectively fed to Lateolabrax japonicus(30.01±0.20)g.Each diet was randomly fed to one group with 3 replicates of 30 individuals and single-factor experimental design was employed in this study.Results indicated that Mannan-oligosaccharide reduced the moisture while the crude protein and the crude lipid increased,and improving the quality of fish effectively.The growth performance of the fish increased among each adding group.While the concentration of additive was 0.2%,weight gain ratio and the specific growth ratio had reached the highest peak and reduced the feed conversion ratio.With increase of Mannan-oligosaccharide level,the digestive enzyme activity of L.Japonicus in each group showed a trend of first rising then falling,For intestinal trypsin,the activities was most significant differences with control group when fish fed with diet adding 0.2%Mannan-oligosaccharide(P<0.05).Amylase and lipase reached maximum.when adding 0.3%.Meanwhile,adding Mannan-oligosaccharide enhanced the activities of serum superoxide dismutase,lysozyme and alkaline phosphatase.When fish fed with diet adding0.2%~0.3%MOS,it reached the maximum.?.Effect of different levels of E.prolifera on growth performance,digestive enzyme activities and serum non-specific immunity of Lateolabrax japonicus.Adding 6 diets 0%,1%,2%,3%,4%,5%fermentated E.prolifera were respectively fed to Lateolabrax japonicus(6.40±0.14)g.Each diet was randomly fed to one group with 3 replicates of 30 individuals and single-factor experimental design was employed in this study.The results showed that with increase of fermentated E.prolifera level,L.japonicus weight gain ratio and the specific growth ratio in each group showed a trend of first rising then falling,and got significant difference finally(P<0.05).While the concentration of additive was 2%,weight gain ratio and the specific growth ratio had reached the highest peak.E.prolifera significantly reduced the feed conversion ratio while the crude protein and the crude lipid increased significantly but no significant differences among each adding group(P>0.05).The activities of intestinal trypsin,amylase and lipase of E.prolifera added groups increased significantly with the control group(P<0.05).For intestinal trypsin,amylase and lipase,the activities reached the maximum,when fish fed with diet adding 2%~3%fermentated E.Prolifera.Meanwhile,adding fermentated E.prolifera enhanced the activities of serum superoxide dismutase and lysozyme significantly(P<0.05),but no significant differences were found in the activities of alkaline phosphatase between trials(P>0.05).Also,the activities of liver superoxide dismutase,lysozyme and alkaline phosphatase increased significantly(P<0.05).Based on results,it was suggested that the optimization 2%to 3%of fermentated E.prolifera as additives.(2)Effect of different levels of combined additives on growth performance,digestive enzyme activities and serum non-specific immunity of Lateolabrax japonicus.Using the orthogonal test design L9(3~4),nine practical diets contained different fermentated E.prolifera(1%,2%,3%),Enteromorpha ultrafine powders(1%,2%,3%),Chinese herbal medicine(0.20%,0.40%,1.20%),with a control were conducted to study.Each diet was randomly fed to one group with 3 replicates of 30 individuals.To evaluate the effects of combined additives on growth performance,digestive enzyme activities and serum non-specific immunity of Lateolabrax japonicus.Results indicated that combined additives can significantly improve the growth performance of Lateolabrax japonicus(P<0.05).The weight gain ratio and the specific growth ratio of D2-D9 groups increased significantly with the control group(P<0.05).The D6 group significantly reduced the feed conversion ratio(P<0.05).From the growth index,D6 group is the optimal combination.Added groups increased the digestive enzyme effectly and promote the nutriment digestion and absorption.For digestive enzymes the D3 group reached the maximum,increased activity of digestive enzymes significantly(P<0.05).Adding combined additiveson enhanced the activities of serum superoxide dismutase,lysozyme and alkaline phosphatase.And D3 group reached the maximum.