Effects Of Eucommia Ulmoides Active Components On Growth,Flesh Quality And Collagen Genes Expression Of Grass Carp (Ctenopharyngodon Idella)

The present study was conducted to investigate the effects of single or combined EU active components,chlorogenic acid,geniposide,geniposidic acid on growth performance,flesh quality,serum biochemical,lipid metabolism,collagen genes express of grass carp,to supply some theoretical basis for improving the flesh quality of cultured fish.1.Effects of dietary chlorogenic acid on growth,flesh quality and serum biochemical indices of grass carp（Ctenopharyngodon idella）The objective of the study was to investigate the effects of dietary chlorogenic acid（CGA）on growth performance,flesh quality,serum biochemical indices of grass carp（Ctenopharyngodon idella）.Seven diets,including control diet,Eucommia ulmoides（EU）supplemented diet(20 g kg^-1)and CGA supplemented diets containing 100,200,400,600,and 800 mg kg^-1 CGA（CGA-100,CGA-200,CGA-400,CGA-600,CGA-800）were designed.A total of 378 grass carp with an average weight（95.1 ± 0.3 g）were fed the seven diets for 70 days.The results indicated that the weight gain was significantly increased by 5.09% by the supplementation of EU（P<0.05）and numerically improved by the supplementation of 400 mg kg^-1 CGA（+2.38%,P>0.05）.Contents of collagen,alkaline-insoluble collagen in muscle and skin were significantly increased by dietary CGA and EU（P<0.05）.Total essential amino acids（TEAA）and total amino acids（TAA）in muscle of grass carp fed EU diet or 400,600,800 mg kg^-1 CGA diet were significantly higher than those of fish fed control diet and 100,200 mg kg^-1 CGA diet（P<0.05）.The fish fed diets containing 200-800 mg kg^-1 CGA showed significantly lower muscle crude lipid content than EU,control and 100 mg kg^-1 CGA groups（P<0.05）.Fish fed CGA supplemented diets(100-800 mg kg^-1)had significantly higher muscle fiber density and lower muscle fiber diameter than control group（P<0.05）.The serum ALP activity of 600,800 mg kg^-1 CGA group and EU group were significantly higher than that of control group（P<0.05）,and the supplementation of 600 mg kg^-1 CGA significantly decreased the serum TG level when compared to the control（P<0.05）.In conclusion,the supplementation of CGA could improve the flesh quality of grass carp,and the supplemental level of CGA for improving flesh quality and growth was estimated to be 400 mg kg^-1 diet.2.Effects of dietary geniposide on growth,flesh quality and lipid metabolism of grass carp（Ctenopharyngodon idella）The aim of this study was to investigate effects of dietary geniposide（GP）on growth performance,flesh quality,lipid metabolism of grass carp（95.2±0.6g）（Ctenopharyngodon idella）fed seven different diets,including control diet,Eucommia ulmoides（EU）supplemented diet(20 g kg^-1)and GP supplemented diets containing 100,200,400,600,and 800 mg kg^-1 GP.Weight gain rate（WGR）was significantly improved（P<0.05）and feed conversation ratio（FCR）was significantly decreased（P<0.05）by supplementation of EU.Grass carp fed 100-800 mg kg^-1 GP supplemented diets showed significantly higher total collagen,alkaline-insoluble collagen content in muscle than control（P<0.05）.Contents of total collagen,alkaline-insoluble collagen content in skin of grass carp were significantly increased by dietary 600-800 mg kg^-1 GP and EU（P<0.05）.Fish fed diets containing 600-800 mg kg^-1 GP showed significantly lower muscle crude lipid content than EU,control and 100-400 mg kg^-1 GP groups（P<0.05）.Fish fed 400-800 mg kg^-1 GP diets had significantly higher muscle fiber density,lower muscle fiber diameter and serum triglyceride（TG）level than the control（P<0.05）.In conclusion,supplementation of GP could improve flesh quality,but not growth of grass carp.The supplemental level of GP for improving flesh quality was estimated to be 400-600 mg kg^-1 diet.3.Effecs of dietary geniposidic acid on growth,flesh quality and collagen genes expression of grass carp（Ctenopharyngodon idella）The objective of the study was to investigate the effects of dietary geniposidic acid（GA）on growth performance,flesh quality,collagen genes expression of grass carp（Ctenopharyngodon idella）.Seven diets,including control diet,Eucommia ulmoides（EU）supplemented diet(20 g kg^-1)and GA supplemented diets containing 200,400,600,800,and 1000 mg kg^-1 GA（GA-200,GA-400,GA-600,GA-800,GA-1000）,were fed to grass carp with an average weight（47.1 ± 0.8 g）for 75 days.The results indicated that weight gain rate（WGR）and feed conversion ratio（FCR）were not significantly affected（P>0.05）,but the contents of total collagen and alkaline-insoluble collagen in skin were increased by the supplementation of 200-1000 mg kg^-1 GA（P<0.05）.Contents of total collagen,alkaline-insoluble collagen,total amino acids（TAA）,total nonessential amino acids（TNEAA）and delicious amino acids（DAA）in muscle were significantly increased（P<0.05）,but lipid content was reduced by the supplementation of 600-1000 mg kg^-1 GA and 2% EU（P<0.05）.The supplementation of 400-1000 mg kg^-1 GA also significantly decreased the steaming loss and cooking loss of flesh（P<0.05）.Fish fed EU and GA supplemented diets(200-1000 mg kg^-1)had significantly higher muscle fiber density,smaller muscle fiber diameter than the control group（P<0.05）.For collagen genes expression,EU and 200-1000 mg kg^-1 GA significantly increased COL1A1 expression in both muscle and skin（P<0.05）,but the expression of COL1A2 in muscle was increased only by the supplementation of 1000 mg kg^-1 GA（P<0.05）,and the expression in skin was increased only by the supplementation of 800-1000 mg kg^-1 GA（P<0.05）.In conclusion,dietary GA could improve the flesh quality,but not the growth of grass carp.The supplemental level of GA for improving flesh quality was estimated to be 600 mg kg^-1 diet.4.Comparison study on effects of GA,CGA and GP on growth,flesh quality and collagen genes expression of grass carp（Ctenopharyngodon idella）The aim of this study was to compare the effects of three EU active components on growth performance,flesh quality and collagen genes express of grass carp（47.2±0.5）（Ctenopharyngodon idella）.Five diets,including control diet,400 mg kg^-1 GA supplemented diet,400 mg kg^-1 CGA supplemented diet,400 mg kg^-1 GP supplemented diet,400 mg kg^-1 active components mixture supplemented diet（GA:CGA:GP）,were fed to grass carp with an average weight（47.2 ± 0.5 g）for 75 days.The results indicated that the weight gain rate（WGR）was improved by 5.22%,and feed conversion rate（FCR）decreased by 0.07 by the supplementation of 400 mg kg^-1 CGA（P<0.05）,but the growth was not significantly affected by the supplementation of 400 mg kg^-1 GP,GA,or the active components mixture.In flesh quality,400 mg kg^-1 CGA,GP,GA:CGA:GP significantly increased flesh total collagen and alkaline-insoluble collagen,flesh amino acids level,muscle fiber density,and reduced the lipid content and cooking loss of flesh（P<0.05）.400 mg kg^-1 GA significantly increased skin total collagen and alkaline-insoluble collagen,muscle fiber density,and reduced the cooking loss of flesh（P<0.05）.In collagen genes expression,400 mg kg^-1 CGA significantly increased the expression of COL1A1 and COL1A2 in both muscle and skin（P<0.05）.400 mg kg^-1 GP,GA:CGA:GP significantly increased the expression of COL1A1 and COL1A2 in muscle and the expression of COL1A2 in skin（P<0.05）,but 400 mg kg^-1 GA only increased the expression of COL1A1,but not the expression of COL1A2 in muscle and skin（P<0.05）.In conclusion,CGA was speculated to be the main active component of the growth-promoting effect of EU.According to their effect degree on the flesh quality,the active components were CGA,GA:CGA:GP,GP and GA,respectively.