Carp is a temperate freshwater fish native to Asia,distributed in all regions of the world except Australia and South America.With the improvement of comprehensive and healthy breeding technology of carp,the unit yiel...Carp is a temperate freshwater fish native to Asia,distributed in all regions of the world except Australia and South America.With the improvement of comprehensive and healthy breeding technology of carp,the unit yield has been greatly increased mainly due to the exten-sive use of compound feed.In this study,the nutritional requirements of carp were summarized from the aspects of protein,amino acids,fat,carbohydrate,calcium and phosphorus,vitamins and taurine.This study provides a certain theoretical reference for scientific formula of carp feed.展开更多
Background:Nutrient regulation has been proven to be an effective way to improve the flesh quality in fish.As a necessary nutrient for fish growth,protein accounts for the highest proportion in the fish diet and is ex...Background:Nutrient regulation has been proven to be an effective way to improve the flesh quality in fish.As a necessary nutrient for fish growth,protein accounts for the highest proportion in the fish diet and is expensive.Although our team found that the effect of protein on the muscle hardness of grass carp was probably related to an increased collagen content,the mechanism for this effect has not been deeply explored.Moreover,few studies have explored the protein requirements of sub-adult grass crap(Ctenopharyngodon idella).Therefore,the effects of different dietary protein levels on the growth performance,nutritional value,muscle hardness,muscle fiber growth,collagen metabolism and related molecule expression in grass carp were investigated.Methods:A total of 450 healthy grass carp(721.16±1.98 g)were selected and assigned randomly to six experimen-tal groups with three replicates each(n=25/replicate),and were fed six diets with 15.91%,19.39%,22.10%,25.59%,28.53%and 31.42%protein for 60 d.Results:Appropriate levels of dietary protein increased the feed intake,percentage weight gain,specific growth rate,body composition,unsaturated fatty acid content in muscle,partial free amino acid content in muscle,and muscle hardness of grass carp.These protein levels also increased the muscle fiber density,the frequency of new muscle fibers,the contents of collagen and IGF-1,and the enzyme activities of prolyl 4-hydroxylases and lysyloxidase,and decreased the activity of matrix metalloproteinase-2.At the molecular level,the optimal dietary protein increased col-lagen type Iα1(Colα1),Colα2,PI3K,Akt,S6K1,La ribonucleoprotein domain family member 6a(LARP6a),TGF-β1,Smad2,Smad4,Smad3,tissue inhibitor of metalloproteinase-2,MyoD,Myf5,MyoG and MyHC relative mRNA levels.The levels of the myostatin-1 and myostatin-2 genes were downregulated,and the protein expression levels of p-Smad2,Smad2,Smad4,p-Akt,Akt,LARP6 and Smad3 were increased.Conclusions:The appropriate levels of dietary protein promoted the growth of sub-adult grass carp and improved muscle hardness by promoting the growth of muscle fibers,improving collagen synthesis and depressing collagen degradation.In addition,the dietary protein requirements of sub-adult grass carp were 26.21%and 24.85%according to the quadratic regression analysis of growth performance(SGR)and the muscle hardness(collagen content),respectively.展开更多
Background Mannan oligosaccharides(MOS)are recommended as aquaculture additives owing to their excellent antioxidant properties.In the present study,we examined the effects of dietary MOS on the head kidney and spleen...Background Mannan oligosaccharides(MOS)are recommended as aquaculture additives owing to their excellent antioxidant properties.In the present study,we examined the effects of dietary MOS on the head kidney and spleen of grass carp(Ctenopharyngodon idella)with Aeromonas hydrophila infection.Methods A total of 540 grass carp were used for the study.They were administered six gradient dosages of the MOS diet(0,200,400,600,800,and 1,000 mg/kg)for 60 d.Subsequently,we performed a 14-day Aeromonas hydrophila challenge experiment.The antioxidant capacity of the head kidney and spleen were examined using spectrophotometry,DNA fragmentation,qRT-PCR,and Western blotting.Results After infection with Aeromonas hydrophila,400-600 mg/kg MOS supplementation decreased the levels of reactive oxygen species,protein carbonyl,and malonaldehyde and increased the levels of anti-superoxide anion,antihydroxyl radical,and glutathione in the head kidney and spleen of grass carp.The activities of copper-zinc superoxide dismutase,manganese superoxide dismutase,catalase,glutathione S-transferase,glutathione reductase,and glutathione peroxidase were also enhanced by supplementation with 400-600 mg/kg MOS.Furthermore,the expression of most antioxidant enzymes and their corresponding genes increased significantly with supplementation of 200-800 mg/kg MOS.mRNA and protein levels of nuclear factor erythroid 2-related factor 2 also increased following supplementation with 400-600 mg/kg MOS.In addition,supplementation with 400-600 mg/kg MOS reduced excessive apoptosis by inhibiting the death receptor pathway and mitochondrial pathway processes.Conclusions Based on the quadratic regression analysis of the above biomarkers(reactive oxygen species,malondialdehyde,and protein carbonyl)of oxidative damage in the head kidney and spleen of on-growing grass carp,the recommended MOS supplementation is 575.21,557.58,531.86,597.35,570.16,and 553.80 mg/kg,respectively.Collectively,MOS supplementation could alleviate oxidative injury in the head kidney and spleen of grass carp infected with Aeromonas hydrophila.展开更多
Background Muscle represents a unique and complex system with many components and comprises the major edible part of animals.Vitamin D is a critical nutrient for animals and is known to enhance calcium absorption and ...Background Muscle represents a unique and complex system with many components and comprises the major edible part of animals.Vitamin D is a critical nutrient for animals and is known to enhance calcium absorption and immune response.In recent years,dietary vitamin D supplementation in livestock has received increased attention due to biological responses including improving shear force in mammalian meat.However,the vitamin D acquisition and myofiber development processes in fish differ from those in mammals,and the effect of vitamin D on fish flesh quality is poorly understood.Here,the influence of dietary vitamin D on fillet quality,antioxidant ability,and myofiber development was examined in grass carp(Ctenopharyngodon idella).Methods A total of 540 healthy grass carp,with an initial average body weight of 257.24±0.63 g,were allotted in 6 experimental groups with 3 replicates each,and respectively fed corresponding diets with 15.2,364.3,782.5,1,167.9,1,573.8,and 1,980.1 IU/kg vitamin D for 70 d.Results Supplementation with 1,167.9 IU/kg vitamin D significantly improved nutritional value and sensory quality of fillets,enhancing crude protein,free amino acid,lipid,and collagen contents;maintaining an ideal pH;and reduc-ing lactate content,shear force,and cooking loss relative to respective values in the control(15.2 IU/kg)group.Average myofiber diameter and the frequency of myofibers>50μm in diameter increased under supplementation with 782.5–1,167.9 IU/kg vitamin D.Levels of oxidative damage biomarkers decreased,and the expression of antioxi-dant enzymes and nuclear factor erythroid 2-related factor 2 signaling molecules was upregulated in the 1,167.9 IU/kg vitamin D treatment compared to respective values in the control group.Furthermore,vitamin D supplementation activated cell differentiation by enhancing the expression of myogenic regulatory factors and myocyte enhancer factors compared to that in the control group.In addition,supplementation with 1,167.9 IU/kg vitamin D improved protein deposition associated with protein synthesis molecule(target of rapamycin)signaling and vitamin D receptor paralogs,along with inhibition of protein degradation(forkhead box protein 1)signaling.Conclusions Overall,the results demonstrated that vitamin D strengthened antioxidant ability and myofiber devel-opment,thereby enhancing nutritional value and sensory quality of fish flesh.These findings suggest that dietary vitamin D supplementation is conducive to the production of nutrient-rich,high quality aquaculture products.展开更多
文摘Carp is a temperate freshwater fish native to Asia,distributed in all regions of the world except Australia and South America.With the improvement of comprehensive and healthy breeding technology of carp,the unit yield has been greatly increased mainly due to the exten-sive use of compound feed.In this study,the nutritional requirements of carp were summarized from the aspects of protein,amino acids,fat,carbohydrate,calcium and phosphorus,vitamins and taurine.This study provides a certain theoretical reference for scientific formula of carp feed.
基金supported by National Key R&D Program of China(2018YFD0900400,2019YFD0900200)National Natural Science Foundation of China for Outstanding Youth Science Foundation(31922086)+3 种基金National Nature Science Foundation of China(32172988)the Young Top-Notch Talent Support Program of National Ten-Thousand Talents Program,the Earmarked Fund for China Agriculture Research System(CARS-45)Outstanding Talents and Innovative Team of Agricultural Scientific Research(Ministry of Agriculture)Supported by Sichuan Science and Technology Program(2019YFN0036).
文摘Background:Nutrient regulation has been proven to be an effective way to improve the flesh quality in fish.As a necessary nutrient for fish growth,protein accounts for the highest proportion in the fish diet and is expensive.Although our team found that the effect of protein on the muscle hardness of grass carp was probably related to an increased collagen content,the mechanism for this effect has not been deeply explored.Moreover,few studies have explored the protein requirements of sub-adult grass crap(Ctenopharyngodon idella).Therefore,the effects of different dietary protein levels on the growth performance,nutritional value,muscle hardness,muscle fiber growth,collagen metabolism and related molecule expression in grass carp were investigated.Methods:A total of 450 healthy grass carp(721.16±1.98 g)were selected and assigned randomly to six experimen-tal groups with three replicates each(n=25/replicate),and were fed six diets with 15.91%,19.39%,22.10%,25.59%,28.53%and 31.42%protein for 60 d.Results:Appropriate levels of dietary protein increased the feed intake,percentage weight gain,specific growth rate,body composition,unsaturated fatty acid content in muscle,partial free amino acid content in muscle,and muscle hardness of grass carp.These protein levels also increased the muscle fiber density,the frequency of new muscle fibers,the contents of collagen and IGF-1,and the enzyme activities of prolyl 4-hydroxylases and lysyloxidase,and decreased the activity of matrix metalloproteinase-2.At the molecular level,the optimal dietary protein increased col-lagen type Iα1(Colα1),Colα2,PI3K,Akt,S6K1,La ribonucleoprotein domain family member 6a(LARP6a),TGF-β1,Smad2,Smad4,Smad3,tissue inhibitor of metalloproteinase-2,MyoD,Myf5,MyoG and MyHC relative mRNA levels.The levels of the myostatin-1 and myostatin-2 genes were downregulated,and the protein expression levels of p-Smad2,Smad2,Smad4,p-Akt,Akt,LARP6 and Smad3 were increased.Conclusions:The appropriate levels of dietary protein promoted the growth of sub-adult grass carp and improved muscle hardness by promoting the growth of muscle fibers,improving collagen synthesis and depressing collagen degradation.In addition,the dietary protein requirements of sub-adult grass carp were 26.21%and 24.85%according to the quadratic regression analysis of growth performance(SGR)and the muscle hardness(collagen content),respectively.
基金financially supported by the National Key R&D Program of China(2019YFD0900200,2018YFD0900400)Supported by the earmarked fund for CARS(CARS-45)+2 种基金National Natural Science Foundation of China for Outstanding Youth Science Foundation(31922086)the Young Top-Notch Talent Support ProgramSichuan Science and Technology Program(2019YFN0036)。
文摘Background Mannan oligosaccharides(MOS)are recommended as aquaculture additives owing to their excellent antioxidant properties.In the present study,we examined the effects of dietary MOS on the head kidney and spleen of grass carp(Ctenopharyngodon idella)with Aeromonas hydrophila infection.Methods A total of 540 grass carp were used for the study.They were administered six gradient dosages of the MOS diet(0,200,400,600,800,and 1,000 mg/kg)for 60 d.Subsequently,we performed a 14-day Aeromonas hydrophila challenge experiment.The antioxidant capacity of the head kidney and spleen were examined using spectrophotometry,DNA fragmentation,qRT-PCR,and Western blotting.Results After infection with Aeromonas hydrophila,400-600 mg/kg MOS supplementation decreased the levels of reactive oxygen species,protein carbonyl,and malonaldehyde and increased the levels of anti-superoxide anion,antihydroxyl radical,and glutathione in the head kidney and spleen of grass carp.The activities of copper-zinc superoxide dismutase,manganese superoxide dismutase,catalase,glutathione S-transferase,glutathione reductase,and glutathione peroxidase were also enhanced by supplementation with 400-600 mg/kg MOS.Furthermore,the expression of most antioxidant enzymes and their corresponding genes increased significantly with supplementation of 200-800 mg/kg MOS.mRNA and protein levels of nuclear factor erythroid 2-related factor 2 also increased following supplementation with 400-600 mg/kg MOS.In addition,supplementation with 400-600 mg/kg MOS reduced excessive apoptosis by inhibiting the death receptor pathway and mitochondrial pathway processes.Conclusions Based on the quadratic regression analysis of the above biomarkers(reactive oxygen species,malondialdehyde,and protein carbonyl)of oxidative damage in the head kidney and spleen of on-growing grass carp,the recommended MOS supplementation is 575.21,557.58,531.86,597.35,570.16,and 553.80 mg/kg,respectively.Collectively,MOS supplementation could alleviate oxidative injury in the head kidney and spleen of grass carp infected with Aeromonas hydrophila.
基金National Key R&D Program of China(2018YFD0900400 and 2019YFD0900200)National Natural Science Foundation of China for Outstanding Youth Science Foundation(31922086)+1 种基金the earmarked fund for CARS(CARS-45)Sichuan Science and Technology Program(2019YFN0036).
文摘Background Muscle represents a unique and complex system with many components and comprises the major edible part of animals.Vitamin D is a critical nutrient for animals and is known to enhance calcium absorption and immune response.In recent years,dietary vitamin D supplementation in livestock has received increased attention due to biological responses including improving shear force in mammalian meat.However,the vitamin D acquisition and myofiber development processes in fish differ from those in mammals,and the effect of vitamin D on fish flesh quality is poorly understood.Here,the influence of dietary vitamin D on fillet quality,antioxidant ability,and myofiber development was examined in grass carp(Ctenopharyngodon idella).Methods A total of 540 healthy grass carp,with an initial average body weight of 257.24±0.63 g,were allotted in 6 experimental groups with 3 replicates each,and respectively fed corresponding diets with 15.2,364.3,782.5,1,167.9,1,573.8,and 1,980.1 IU/kg vitamin D for 70 d.Results Supplementation with 1,167.9 IU/kg vitamin D significantly improved nutritional value and sensory quality of fillets,enhancing crude protein,free amino acid,lipid,and collagen contents;maintaining an ideal pH;and reduc-ing lactate content,shear force,and cooking loss relative to respective values in the control(15.2 IU/kg)group.Average myofiber diameter and the frequency of myofibers>50μm in diameter increased under supplementation with 782.5–1,167.9 IU/kg vitamin D.Levels of oxidative damage biomarkers decreased,and the expression of antioxi-dant enzymes and nuclear factor erythroid 2-related factor 2 signaling molecules was upregulated in the 1,167.9 IU/kg vitamin D treatment compared to respective values in the control group.Furthermore,vitamin D supplementation activated cell differentiation by enhancing the expression of myogenic regulatory factors and myocyte enhancer factors compared to that in the control group.In addition,supplementation with 1,167.9 IU/kg vitamin D improved protein deposition associated with protein synthesis molecule(target of rapamycin)signaling and vitamin D receptor paralogs,along with inhibition of protein degradation(forkhead box protein 1)signaling.Conclusions Overall,the results demonstrated that vitamin D strengthened antioxidant ability and myofiber devel-opment,thereby enhancing nutritional value and sensory quality of fish flesh.These findings suggest that dietary vitamin D supplementation is conducive to the production of nutrient-rich,high quality aquaculture products.
