Background Hesperidin is a citrus flavonoid with anti-inflammatory and antioxidant potential. However, its protective effects on bovine mammary epithelial cells(b MECs) exposed to oxidative stress have not been elucid...Background Hesperidin is a citrus flavonoid with anti-inflammatory and antioxidant potential. However, its protective effects on bovine mammary epithelial cells(b MECs) exposed to oxidative stress have not been elucidated.Results In this study, we investigated the effects of hesperidin on H_(2)O_(2)-induced oxidative stress in b MECs and the underlying molecular mechanism. We found that hesperidin attenuated H_(2)O_(2)-induced cell damage by reducing reactive oxygen species(ROS) and malondialdehyde(MDA) levels, increasing catalase(CAT) activity, and improving cell proliferation and mitochondrial membrane potential. Moreover, hesperidin activated the Keap1/Nrf2/ARE signaling pathway by inducing the nuclear translocation of Nrf2 and the expression of its downstream genes NQO1 and HO-1, which are antioxidant enzymes involved in ROS scavenging and cellular redox balance. The protective effects of hesperidin were blocked by the Nrf2 inhibitor ML385, indicating that they were Nrf2 dependent.Conclusions Our results suggest that hesperidin could protect b MECs from oxidative stress injury by activating the Nrf2 signaling pathway, suggesting that hesperidin as a natural antioxidant has positive potential as a feed additive or plant drug to promote the health benefits of bovine mammary.展开更多
Manipulation of perinatal diets,such as supplementing feed with rumen-protected glucose(RPG),has been positively regarded as a strategy to improve milking performance.This study was conducted to assess the effects of ...Manipulation of perinatal diets,such as supplementing feed with rumen-protected glucose(RPG),has been positively regarded as a strategy to improve milking performance.This study was conducted to assess the effects of RPG on the fermentation profiles,resident microbiota and mucosal immunity in the cecum.Ten Holstein dairy cows were randomly assigned to either a 25 g/kg RPG diet(DM basis)or a 11 g/kg coating fat diet(control,CON).Compared with the CON group,the acetate-to-propionate ratio was lower in the RPG group.Gene expression analysis indicated that RPG supplementation tended to upregulate the expression of Na^(+)/H^(+)hydrogen exchanger 3(NHE3)(P=0.076).RPG supplementation downregulated the expression of genes involved in self-rehabilitation such as matrix metalloproteinase 1(MMP1),MMP3,MMP9 and MMP13.Additionally,the mRNA expression of genes involved in immunity including Toll-like receptors(TLR4,TLR6 and TLR7)and proinflammatory cytokines(immune interferon gamma[IFNG]and interleukins interleukin 17 A[IL7 F],IL17 A,IL22),was downregulated by RPG supplementation.Nonetheless,no differences existed in the bacterial copy number and beta diversity between the 2 groups.Overall,supplementation with RPG would probably cause a shift towards propionate production in the cecal digesta,and promote the immune homeostasis of the cecal mucosa in transition dairy cows.Our results extended the basic understanding of RPG supplementation and utilization in transition dairy cows in terms of host microbe interplay in the cecum.展开更多
Enteric methane emission is not only a source of energy loss in ruminants, but also a potent contributor to greenhouse gas production. To identify the nature and timing of interventions to reduce methane emissions req...Enteric methane emission is not only a source of energy loss in ruminants, but also a potent contributor to greenhouse gas production. To identify the nature and timing of interventions to reduce methane emissions requires knowledge of temporal kinetics of methane emissions during animal husbandry.Accordingly, a mathematical model was developed to investigate the pattern of enteric methane emissions after feeding in dairy cows. The model facilitated estimation of total enteric methane emissions（V,g） produced by the residual substrate（V1, g） and newly ingested feed（V2, g）. The model was fitted to the10 h methane emission patterns after morning feeding of 16 non-lactating dairy cows with various body weights（BW）, and the obtained parameters were used to predict the kinetics of 24 h methane emission for each animal. The rate of methane emission（g/h） reached a maximum within 1 to 2 h after feeding,followed by a gradual post-prandial decline to a basal value before the next feeding. The model satisfactorily fitted curves for each cow according to the criterion of goodness-of-fit, and provided biological descriptions for fluctuations in methane emissions based on basal V1 and feeding V2 in response to the changes in BW and dry matter intake（DMI） of different dairy cows. The basal V1 and feeding V2 are probably maintained by slow-and readily-degradable substrates, respectively. The former contributed at least 0.6 of methane production. In summary, the model provides a means to separate basal V1 and feeding V2 within V, and can be used to predict 24 h emission from a single feeding period.展开更多
Ramie(Boehmeria nivea)is noted for the production of a large biomass that has a high protein content and is rich in antioxidants.It may thus serve as a high-quality forage material to replace alfalfa and improve the m...Ramie(Boehmeria nivea)is noted for the production of a large biomass that has a high protein content and is rich in antioxidants.It may thus serve as a high-quality forage material to replace alfalfa and improve the meat quality of farmed animals.In this study,we evaluated the carcass characteristics and meat quality of goats when 0,35%,75%,and 100%of dietary alfalfa was replaced with ramie.Crude protein content(linear,P<0.0001)and key muscle color values at 24 h after slaughter decreased with increasing ramie levels.The content of most individual amino acids,non-essential amino acids(NEAA),total amino acids(TAA),branched chain amino acids(BCAA),functional amino acids(FAA),and flavor amino acids(DAA)decreased(P<0.05)with increasing dietary ramie.The diet in which 35%of alfalfa was replaced with ramie yielded meat with the highest amino acid content,whereas the fatty acid profile was unaffected by the inclusion of ramie.These results indicate that ramie could be used as a potential dietary forage resource for goats,and that substituting 35%of alfalfa with ramie,which is equivalent to 126 g/kg DM content,would be optimal in terms of goat meat quality.展开更多
In this report,we give a viscosity splitting method for the Navier-Stokes/Darcy problem.In this method,the Navier-Stokes/Darcy equation is solved in three steps.In the first step,an explicit/implicit formulation is us...In this report,we give a viscosity splitting method for the Navier-Stokes/Darcy problem.In this method,the Navier-Stokes/Darcy equation is solved in three steps.In the first step,an explicit/implicit formulation is used to solve the nonlinear problem.We introduce an artificial diffusion term qDu in our scheme whose purpose is to enlarge the time stepping and enhance numerical stability,especially for small viscosity parameter n,by choosing suitable parameter q.In the second step,we solve the Stokes equation for velocity and pressure.In the third step,we solve the Darcy equation for the piezometric head in the porous media domain.We use the numerical solutions at last time level to give the interface condition to decouple the Navier-Stokes equation and the Darcy’s equation.The stability analysis,under some condition △t≤k0,k0>0,is given.The error estimates prove our method has an optimal convergence rates.Finally,some numerical results are presented to show the performance of our algorithm.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA26040304)。
文摘Background Hesperidin is a citrus flavonoid with anti-inflammatory and antioxidant potential. However, its protective effects on bovine mammary epithelial cells(b MECs) exposed to oxidative stress have not been elucidated.Results In this study, we investigated the effects of hesperidin on H_(2)O_(2)-induced oxidative stress in b MECs and the underlying molecular mechanism. We found that hesperidin attenuated H_(2)O_(2)-induced cell damage by reducing reactive oxygen species(ROS) and malondialdehyde(MDA) levels, increasing catalase(CAT) activity, and improving cell proliferation and mitochondrial membrane potential. Moreover, hesperidin activated the Keap1/Nrf2/ARE signaling pathway by inducing the nuclear translocation of Nrf2 and the expression of its downstream genes NQO1 and HO-1, which are antioxidant enzymes involved in ROS scavenging and cellular redox balance. The protective effects of hesperidin were blocked by the Nrf2 inhibitor ML385, indicating that they were Nrf2 dependent.Conclusions Our results suggest that hesperidin could protect b MECs from oxidative stress injury by activating the Nrf2 signaling pathway, suggesting that hesperidin as a natural antioxidant has positive potential as a feed additive or plant drug to promote the health benefits of bovine mammary.
基金supported by the National Key Research and Development Program of China(grant no.2016YFD0501206 and 2018YFD0501604)the Major Project for Science and Technology of Hunan Province(grants no.2017NK1020)+1 种基金the CAS Pioneer Hundred Talents Program and Youth Innovation Team Project of ISA,CAS(2017QNCXTDZCS)the CAS Science and Technology Service Network Initiative(KFJ-STS-ZDTP-056)。
文摘Manipulation of perinatal diets,such as supplementing feed with rumen-protected glucose(RPG),has been positively regarded as a strategy to improve milking performance.This study was conducted to assess the effects of RPG on the fermentation profiles,resident microbiota and mucosal immunity in the cecum.Ten Holstein dairy cows were randomly assigned to either a 25 g/kg RPG diet(DM basis)or a 11 g/kg coating fat diet(control,CON).Compared with the CON group,the acetate-to-propionate ratio was lower in the RPG group.Gene expression analysis indicated that RPG supplementation tended to upregulate the expression of Na^(+)/H^(+)hydrogen exchanger 3(NHE3)(P=0.076).RPG supplementation downregulated the expression of genes involved in self-rehabilitation such as matrix metalloproteinase 1(MMP1),MMP3,MMP9 and MMP13.Additionally,the mRNA expression of genes involved in immunity including Toll-like receptors(TLR4,TLR6 and TLR7)and proinflammatory cytokines(immune interferon gamma[IFNG]and interleukins interleukin 17 A[IL7 F],IL17 A,IL22),was downregulated by RPG supplementation.Nonetheless,no differences existed in the bacterial copy number and beta diversity between the 2 groups.Overall,supplementation with RPG would probably cause a shift towards propionate production in the cecal digesta,and promote the immune homeostasis of the cecal mucosa in transition dairy cows.Our results extended the basic understanding of RPG supplementation and utilization in transition dairy cows in terms of host microbe interplay in the cecum.
基金“Strategic Priority Research ProgramClimate Change:Carbon Budget and Relevant Issues”(Grant No.XDA05020700)the National Natural Science Foundation of China(Grant No.31472133,31561143009 and 31320103917)International Atomic Energy Agency(Grant No.16315)for the joint financial supports
文摘Enteric methane emission is not only a source of energy loss in ruminants, but also a potent contributor to greenhouse gas production. To identify the nature and timing of interventions to reduce methane emissions requires knowledge of temporal kinetics of methane emissions during animal husbandry.Accordingly, a mathematical model was developed to investigate the pattern of enteric methane emissions after feeding in dairy cows. The model facilitated estimation of total enteric methane emissions（V,g） produced by the residual substrate（V1, g） and newly ingested feed（V2, g）. The model was fitted to the10 h methane emission patterns after morning feeding of 16 non-lactating dairy cows with various body weights（BW）, and the obtained parameters were used to predict the kinetics of 24 h methane emission for each animal. The rate of methane emission（g/h） reached a maximum within 1 to 2 h after feeding,followed by a gradual post-prandial decline to a basal value before the next feeding. The model satisfactorily fitted curves for each cow according to the criterion of goodness-of-fit, and provided biological descriptions for fluctuations in methane emissions based on basal V1 and feeding V2 in response to the changes in BW and dry matter intake（DMI） of different dairy cows. The basal V1 and feeding V2 are probably maintained by slow-and readily-degradable substrates, respectively. The former contributed at least 0.6 of methane production. In summary, the model provides a means to separate basal V1 and feeding V2 within V, and can be used to predict 24 h emission from a single feeding period.
基金financially supported by the National Key Research and Development Program of China(No.2018YFD0501604,2018YFD0501900)China Special Fund for Agro-Scientific Research in the Public Interest(No.201303144)+2 种基金the National Natural Science Foundation of China(No.31501988)Hunan Provincial Major Scientific and Technological Special Project(No.2017NK1020)Key Research and Development Program of Hunan Province(No.2016NK2171)
文摘Ramie(Boehmeria nivea)is noted for the production of a large biomass that has a high protein content and is rich in antioxidants.It may thus serve as a high-quality forage material to replace alfalfa and improve the meat quality of farmed animals.In this study,we evaluated the carcass characteristics and meat quality of goats when 0,35%,75%,and 100%of dietary alfalfa was replaced with ramie.Crude protein content(linear,P<0.0001)and key muscle color values at 24 h after slaughter decreased with increasing ramie levels.The content of most individual amino acids,non-essential amino acids(NEAA),total amino acids(TAA),branched chain amino acids(BCAA),functional amino acids(FAA),and flavor amino acids(DAA)decreased(P<0.05)with increasing dietary ramie.The diet in which 35%of alfalfa was replaced with ramie yielded meat with the highest amino acid content,whereas the fatty acid profile was unaffected by the inclusion of ramie.These results indicate that ramie could be used as a potential dietary forage resource for goats,and that substituting 35%of alfalfa with ramie,which is equivalent to 126 g/kg DM content,would be optimal in terms of goat meat quality.
文摘In this report,we give a viscosity splitting method for the Navier-Stokes/Darcy problem.In this method,the Navier-Stokes/Darcy equation is solved in three steps.In the first step,an explicit/implicit formulation is used to solve the nonlinear problem.We introduce an artificial diffusion term qDu in our scheme whose purpose is to enlarge the time stepping and enhance numerical stability,especially for small viscosity parameter n,by choosing suitable parameter q.In the second step,we solve the Stokes equation for velocity and pressure.In the third step,we solve the Darcy equation for the piezometric head in the porous media domain.We use the numerical solutions at last time level to give the interface condition to decouple the Navier-Stokes equation and the Darcy’s equation.The stability analysis,under some condition △t≤k0,k0>0,is given.The error estimates prove our method has an optimal convergence rates.Finally,some numerical results are presented to show the performance of our algorithm.
