Effects Of Four Nutrients And Bacillus Subtilis On Growth Performance And Non-Specific Immunity Of Misgurnus Anguillcaudatus Juvenile

The research project consisted of two experiments.The first experiment was conducted to study the effect of four nutrients on growth performance of Misgurnus anguillcaudatus juvenile,and to investigate the optimum contents of protein,fat,cellulose and carbohydrate in the formulated diet of Misgurnus anguillcaudatus juvenile.The second experiment was to evaluate the effects of Bacillus subtilis on growth performance and non-specific immunity of Misgurnus anguillcaudatus juvenile,and to find out the appropriate supplemental level of Bacillus subtilis in diets.In Exp.1,to study the effect of protein,fat,cellulose and carbohydrate on growth performance of Misgurnus anguillcaudatus juvenile.The optimum contents of protein,fat,carbohydrate and cellulose in the formulated diet of Misgurnus anguillcaudatus juvenile with initial weight of?1.23±0.09?g were studied.The L₉?3⁴?table of orthogonal design method was employed to formulate nine diet combinations,while each nutrient in the components was designed as 3 levels:protein 25%,30%,35%;fat 4%,8%,12%;carbohydrate20%,25%,30%;cellulose 1.6%².0%,2.0%².4%,2.4%².8%.After feeding for 38 days,the result of experiment show that the effects of nutrients on the WGR,SGR and PER ranked in the following order:protein>fat>cellulose>carbohydrate.When the feed contains protein 35%,fat 8%,carbohydrate 30%and cellulose 1.6%-2.0%,the WGR?SGR and PER of Misgurnus anguillcaudatus juvenile were the highest,the lowest FCR,and the differences of CF in all the groups were not significant?P>0.05?.By comprehensive analysis and comparison,it is concluded that protein was the main nutrient?P<0.05?,while the effects of fat,cellulose and carbohydrate were not so pronounced in the present experiment.The optimum contents of various nutrition in the formulated diet of Misgurnus anguillcaudatus juvenile were found to be:crude protein 35%,fat 8%,carbohydrate 25%³0%,cellulose1.6%².0%.In Exp.2,to evaluate the effects of Bacillus subtilis on growth performance and non-specific immunity of Misgurnus anguillcaudatus juvenile.Misgurnus anguillcaudatus juvenile with an initial body weight of?0.55±0.16?g were randomly divided into 3 groups?G1^G3?.Each group had 3 replicates with50 fish per replicate.Misgurnus anguillcaudatus juvenile were fed 3experimental diets supplemented with 0,1.0×10⁷,1.0×10⁸ cfu/g Bacillus subtilis for 38 days,respectively.After the experiment,each group were sample to measure the index of growth performance and non-specific immunity.The results showed as follows:?1?Compared with the control group,the WGR,SGR and PER of G2 and G3 groups were significantly increased?P<0.05?,while the FCR of G2 and G3groups were significantly decreased?P<0.05?;there was no significant difference in CF of the three groups?P>0.05?.G3 group was better than G2 group in WGR,SGR,CF,PER and FCR,but the difference was not significant?P>0.05?.?2?Compared with the control group,the activities of GSH-Px,T-AOC of G2,G3 groups and the T-SOD of G3 group were significantly increased?P<0.05?;the LZM content in G2 and G3 groups was increased,but the difference was not significant?P>0.05?;the content of MDA in G2 an G3 groups was decreased,but the difference was not significant?P>0.05?too.In conclusion,diets supplemented with Bacillus subtilis can significantly improve the growth performance and antioxidant capacity and non-specific immune function of Misgurnus anguillcaudatus juvenile.Comprehensive changes of the indicators showed that the suitable addition amount of Bacillus subtilis under the conditions of this experiment was1.0×10⁸cfu/g.