Comparative Study Of Effect Of Two Kinds Of Feed On Body Characteristics And Muscle Quality Of Grass Crap(Ctenopharyngodon Idellus)

In this experiment,grass crap（Ctenopharyngodon idellus）were fed two different feeds that are new-type feed（Trial group）and Commerical formulate feed（Control group）.The water quality and sediment of two group ponds were measured.The somatotype index,pH,hydroxyproline,collagen,water-holding capacity,texture profiles parameters,common nutrition compositions,mineral element content,amino acids,fatty acids in muscle of grass crap of two groups were comparatively analyzed.The current study is aiming to investigate the effect on water quality and sediment of two kinds of pond as well as to provide a reference for muscle quality and nutrition compositions of grass carp.The results illustrated as follows:（1）During feeding,the conductivity and total dissolved solids in pond water of the trial group were significantly lower than those of the control group（P<0.05）,whereas transmittance of pond water in trial group was siginficantly higher than this of the control group（P<0.05）.The concentrations of NH₄⁺-N,NO₃^–-N,NO₂^–-N,TN,PO₄^3–-P and TP in middle pond water in the trial group were significantly lower than those of the control group（P<0.05）.The concentrations of TN and TP in pond sediments in the trial group were significantly lower than those of the control group（P<0.05）.（2）The viscera somatic index（VSI）,hepatosomatic index（HSI）,Intraperitoneal fat index（IFI）and Condition factor of the Trial group were significantly lower than those of the Control group（P<0.05）,whereas the shell rate of the Trial group was significantly higher than that of the Control group（P<0.05）.The content of crude fat in muscle of the trial group was significantly lower than that of the control group（P<0.05）.The content of Fe in the trial group was significantly higher than that of the control group（P<0.05）.（3）Some textural mechanical properties of dorsal muscle of grass crap such as springiness,hardness,chewiness,gumminess and cohesiveness were significantly higher in the trial group than those of the control group（P<0.05）.The trial group showed the pH,hydroxyproline and collagen significantly higher than those of the control group（P<0.05）.Some parameters of the water-holding capacity such as drip loss,thawing loss and liquid loss in trial group higher than those of the control group（P<0.05）.The muscle fibres diameter in trial group was significantly higher than that of the contol group（P<0.05）,whereas the muscle fibre density in trial group was significantly lower than that of the control group（P<0.05）.（4）These muscles in the trial group and control group contained 16 amino acids,accounting for 17.43%and 17.23%,respectively.The content of delicious amino acids in both of these two groups were 6.88%and 6.78%,respectively.The EAA/SEAA value of the trial group was significantly lower than that of the control group（P<0.05）.According to the criteria of amino score（AAS）and chemical score（CS）,the first limiting amino acids in muscle were methionine and cystine,the second limiting amino acid in muscle was valine.The essential amino acid index of the trial group was 84.66 compared with 84.94 for the control group.The F vlaue of the trial group and contol group were 2.33 and 2.44,respectively.The two groups of the fish determined the content of the most fatty acids.A total of 16 fatty acids were detected in both group,respectively.The oleic C18:1 level was significantly higher in the treated group than that of the control group（P<0.05）,but the linoleic C18:2,C20:3 and C20:4 level were significantly lower in the tcontrol group compared to the treated group（P<0.05）.The monounsaturated fatty acids（MUFA）in the trial group was significantly higher than that of the control group（P<0.05）,where the trial group had lower the polyunsaturated fatty acids（FUFA）（P<0.05）.On the other hand,the∑ω-3 PUFA and∑ω-6 PUFA were significantly lower in treated group in comparison with the control group（P<0.05）,whereas EPA/DHA value was significantly higher than that of the control group（P<0.05）.To sum up in conclusion,water quality and semidment in ponds of trial group were significantly well those of control group.New-type feed can effectively reduce the impact on pond pollution.In comparison to Commerical formulated feed,New-type feed can significantly improve muscle quality of grass crap.