Background Zearalenone(ZEN),a common mycotoxin in ruminant diets,could disturb the rumen ecosystem and impair rumen fermentation.Noticeably,ZEN has been shown to reduce the relative abundances of specific bacterial ta...Background Zearalenone(ZEN),a common mycotoxin in ruminant diets,could disturb the rumen ecosystem and impair rumen fermentation.Noticeably,ZEN has been shown to reduce the relative abundances of specific bacterial taxa that potentially possess quorum sensing(QS)functions,which are deemed essential for the microbial interactions and adaptations during rumen fermentation.Nonetheless,whether QS communications participate in the responses of rumen microbial fermentation to ZEN remains unknown.Therefore,the present trial was performed to explore the potential roles of QS during the alterations of rumen microbial fermentation by ZEN through a rumen simulation technique(RUSITEC)system,in a replicated 4×4 Latin square design.Results ZEN significantly(P<0.05)reduced QS signal autoinducer-2(AI-2),and tended to(P=0.051)downregulate QS signal C4-homoserine lactone(HSL).ZEN also significantly(P<0.05)decreased total volatile fatty acid(TVFA),acetate,propionate,isobutyrate,isovalerate,organic matter disappearance(OMD),neutral detergent fiber disappearance(NDFD),and acid detergent fiber disappearance(ADFD)in different manners.The linear discriminant analysis effect size(LEf Se)analysis indicated significantly(P<0.05)differential enrichments of a series of bacterial taxa such as Butyrivibrio_sp_X503,Rhizobium daejeonense,Hoylesella buccalis,Ezakiella coagulans,Enterococcus cecorum,Ruminococcus_sp_zg-924,Polystyrenella longa,and Methylacidimicrobium fagopyrum across different treatments.The phylogenetic investigation of communities by reconstruction of unobserved states 2(PICRUSt2)analysis suggested that QS were predicted to be significantly(P<0.05)affected by ZEN.The metabolomics analysis detected considerable significantly(P<0.05)differing metabolites and implied that ZEN challenge significantly(P<0.05)influenced the indole alkaloid biosynthesis,biosynthesis of alkaloids derived from shikimate pathway,and sesquiterpenoid and triterpenoid biosynthesis.Significant(P<0.05)interconnections of QS molecules with the differential rumen fermentation traits,differential bacterial taxa,and differential metabolites were exhibited by Spearman analysis.Conclusions ZEN negatively affected the QS signals of AI-2 and C4-HSL,which was found to correlate with the fluctuations in specific rumen fermentation characteristics,ruminal bacterial populations,and ruminal metabolisms.These interrelationships implied the potential involvement of QS in the reactions of rumen microbiota to ZEN contamination,and probably contributed to the inhibition of rumen fermentation.展开更多
Background In this study,the effects of L-leucine(Leu)on rumen fermentation parameters,rumen epithelium development,amino acid composition,rumen bacterial communities and rumen metabolites in beef cattle were investig...Background In this study,the effects of L-leucine(Leu)on rumen fermentation parameters,rumen epithelium development,amino acid composition,rumen bacterial communities and rumen metabolites in beef cattle were investigated.Twenty-four fattening Angus females of similar initial weight(575.5±22.1 kg)were randomly assigned to 2 treatments with 4 replicate pens(3 cattle per pen).They were fed either a basal diet or a basal diet supplemented with 6.0 g L-Leu/100 kg BW/d for 120 d.Results(1)Leu increased the ruminal concentrations of total volatile fatty acid(VFA)(P=0.017),propionate(P=0.023),isovalerate(P=0.001),and branched-chain volatile fatty acid(BCVFA)(P=0.01)at 4 h post-feeding.It also tended to increase acetate(P=0.083)and decrease the ammonia-N(NH_3-N)concentration(P=0.055),but it did not affect ruminal pH(P>0.1).Leu also increased microbial crude protein(MCP)(P=0.026)at 4 h post-feeding,but decreased MCP at 8 h post-feeding(P=0.010).(2)Supplementation with L-Leu increased the ruminal concentrations of phenylalanine(P=0.011),lysine(P=0.034),and tyrosine(P=0.033),while decreasing the cystine concentration(P=0.010).(3)Leu increased the thickness of the stratum spinosum and basal(P<0.05),while decreasing the thickness of the stratum granulosum(P<0.05).(4)Leu upregulated the relative mRNA abundance of genes involved in tight junction proteins(P<0.05)and VFA absorption and metabolism(P<0.01)in the rumen epithelium.This upregulation was positively correlated with the concentrations ruminal isovalerate and BCVFA(P<0.01).(5)L-Leu did not affect the diversity and richness of ruminal microbes(P>0.05),but differential bacterial biomarkers(LEfSe,LDA>2)were either positively or negatively correlated with ruminal MCP,NH_3-N,and BCVFA concentrations(P<0.001).Additionally,differential bacterial metabolites(OPLS-DA,VIP>1.5)were primarily enriched in the amino acid metabolism pathway and the cofactors and vitamins metabolism pathway(P<0.05).Conclusions Dietary supplementation with L-Leu altered rumen fermentation parameters and patterns,improved rumen epithelial morphology,and enhanced the expression of genes related to VFA absorption and metabolism in the rumen epithelium of beef cattle.展开更多
The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR ) is an essential enzyme in cholesterol biosynthesis. To study the expression of HMGR in adipose and muscle tissues, and some performance indexes of four age stages, ...The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR ) is an essential enzyme in cholesterol biosynthesis. To study the expression of HMGR in adipose and muscle tissues, and some performance indexes of four age stages, twelve Lilu cattle were selected. The results indicated that the Lilu beef cattle have good production and slaughter performance. HMGR mRNA expression level in adipose was higher than in muscle, but the trend in adipose was the same as in muscle. HMGR mRNA expression is difference in adipose and muscle tissues suggesting this gene is expressed in a tissue-dependent manner in cattle. Understanding the causes of variation in HMGR gene expression may provide crucial information about cholesterol biosynthesis in Lilu beef cattle.展开更多
This study was to evaluate how low phosphorus(P)diets affect growth performance and fecal P excretion in Xia-Nan cattle and to elucidate the underlying mechanisms.Thirty-two healthy Xia-Nan bulls with similar body wei...This study was to evaluate how low phosphorus(P)diets affect growth performance and fecal P excretion in Xia-Nan cattle and to elucidate the underlying mechanisms.Thirty-two healthy Xia-Nan bulls with similar body weights(BW;267.42±45.77 kg)were assigned to four groups with eight individual replicate pens per group in a completely randomized block design,stratified by initial BW and average dry matter intake(DMI).Cattle were fed total mixed rations(concentrate-to-forage ratio 40:60)with varying dietary P levels(DM basis):0.16%(XPA),0.19%(XPB),0.22%(XPC),and 0.25%(XPD;control)for 90 d.The first three groups were considered low-P treatments.Compared with the XPD group,XPA showed significantly lower average daily gain(ADG;P=0.018)and DMI(P=0.046),while XPB and XPC showed no differences(P>0.05).XPB group showed a significant lower feed conversion ratio(FCR)than XPA(P=0.049)and had the lowest FCR among all groups.Total-tract apparent digestibility of calcium(Ca;P=0.006)and P(P=0.006)decreased linearly with dietary P reduction.P intake(P<0.001)and fecal P content(P<0.001)were significantly lower in low-P groups than in the XPD group and decreased linearly with P reduction.Serum concentrations of parathormone hormone(PTH;P<0.001),1,25-dihydroxyvitamin D_(3)(1,25(OH)_(2)D_(3);P=0.005),Ca(P<0.001),and P(P<0.001)were positively correlated with decreasing dietary P levels,whereas calcitonin(CT;P=0.016)and alkaline phosphatase(ALP;P=0.006)were negatively correlated.XPB and XPD groups had higher molar proportions of propionate(P<0.001)and butyrate(P=0.006)but lower acetate molar proportion(P<0.001)and acetate-to-propionate ratio(P<0.001)than XPA.Fecal P excretion correlated positively with Ruminococcaceae_UCG-005,Saccharofermentans,and Butyrivibrio,and negatively with Rikenellaceae_RC9_gut_group and uncultured_bacteriumf_F082.These results suggest that reducing dietary P to 0.19%(XPB)maintained optimal growth performance while reducing environmental P pollution in XiaNan cattle.展开更多
Grape peel,as the by-product of grape wine,is rich in phenolic and proanthocyanidins.Obesity has become a serious global public health problem and supplementation of grape peel phenolics(GPP)may be an effective interv...Grape peel,as the by-product of grape wine,is rich in phenolic and proanthocyanidins.Obesity has become a serious global public health problem and supplementation of grape peel phenolics(GPP)may be an effective intervention method.From a dietary nutrition perspective,this study aims to investigate the effects of GPP on improving intestinal barrier function in high-fat diet-treated mice,and further explore the potential mechanism.The results showed that GPP supplementation obviously reduced body weight of mice,increased the abundance of beneficial bacteria(Akkermansia,g_Lachnospiraceae_NK4A136_group,Bacteroidetes and g_norank_f_Muribaculaceae),reduced the relative abundance of harmful bacteria(g_Coriobacteriaceae_UCG-002,g_Dubosiella and Romboutsia).Meanwhile,GPP could alleviate colonic barrier inflammation,facilitate the production of short-chain fatty acids and secondary bile acids,increase the mRNA and protein expression levels of intestinal tight junction proteins,and protect intestinal barrier integrity,especially in the LGPP group(100 mg/kg·day GPP).Kyoto Encyclopedia of Genes and Genomes analysis on fecal metabolism indicated that GPP could effectively alleviate intestinal imbalance caused by obesity through targeting multiple shared pathways.Bile secretion and arachidonic acid are the key differential metabolic pathways,and 14 key differential metabolites were identified.In conclusion,GPP supplementation has the potential to alleviate obesity by regulating gut microbiota,improving gut barrier integrity,and modulating the related metabolites.展开更多
The present trial was performed to reveal the regulatory effects of L-theanine on the levels of lipopolysaccharide(LPS)endotoxin within different biofluids,as well as relevant inflammatory responses of dairy cattle un...The present trial was performed to reveal the regulatory effects of L-theanine on the levels of lipopolysaccharide(LPS)endotoxin within different biofluids,as well as relevant inflammatory responses of dairy cattle under heat stress conditions.Thirty lactating Chinese Holstein dairy cattle(189±47 d in milk,and 2±1 parities)were allocated in a completely randomized design to each of 3 dietary treatments:the control(CON,0 g/d per cow L-theanine),the low L-theanine dosage treatment(LL,16 g/d per cow L-theanine),and the high L-theanine dosage treatment(HL,32 g/d per cow L-theanine).This trial consisted of 38 d(7 d for adaption and 31 d for data and sample collection),and sample collection for rumen liquid,blood plasma or serum,and milk were conducted on the d 27 and 38,respectively.Dairy cattle were constantly exposed to environmental heat stress during this experiment according to the recorded temperature-humidity index(THI).In the LL treatment,LPS concentration in rumen liquid was higher(P<0.05),whilst LPS densities in plasma and milk were lower(P<0.05)than those of the CON.Supplementing L-theanine at 2 dosages both significantly lowered(P<0.05)the level of interleukin(IL)-1βin the serum.Results of the present study suggested that L-theanine could be a promising additive in reducing the detrimental effects of heat stress on dairy cows,and L-theanine supplementation at 16 g/d per cow is preferred because it reduced the LPS translocation into the peripheral blood and LPS accumulation in the milk,as well as mitigated LPS-induced inflammatory reactions in dairy cows during heat stress.Further studies are necessitated to investigate the underlying mechanisms of L-theanine in LPS alteration and inflammation alleviation.展开更多
The purpose of this study was to investigate the effects of dietary L-theanine supplementation on apparent nutrient digestibility,milk yield,milk composition,and blood biochemical indices of dairy cows under heat stre...The purpose of this study was to investigate the effects of dietary L-theanine supplementation on apparent nutrient digestibility,milk yield,milk composition,and blood biochemical indices of dairy cows under heat stress.Thirty Chinese Holstein cows(19.84±2.42 kg milk/d,192.36±40.77 d in milk and2±0.93 parities)were divided into 3 groups of 10 animals each.The control group was fed a basal total mixed ration(TMR)diet,while treatment 1(LTA16)and treatment 2(LTA32)groups were fed a basal TMR diet supplemented with L-theanine at 16 and 32 g/cow per day,respectively.The results showed that feeding the dairy cows with LTA16 treatment decreased(P<0.05)their rectal temperature,whereas feeding with LTA32 treatment decreased(P<0.05)their rumen fluid ammonia nitrogen content.In comparison to the control group,the supplementation of L-theanine had no significant effect(P>0.05)on the dry matter intake,nutrient digestibility,total volatile fatty acid(TVFA)concentration and molar proportion of volatile fatty acid,milk yield,milk composition,feed efficiency and antioxidant capacity of the dairy cows.The triglyceride(TG)content of the LTA32 group was significantly greater(P=0.014)than that of the control group.With the increase in L-theanine dosage,the serum cholesterol(CHOL)content significantly increased(P=0.013).The serum albumin(ALB;P=0.067),low-density lipoprotein cholesterol(LDL-C;P=0.053),and high-density lipoprotein cholesterol(HDL-C;P=0.067)contents showed an upward trend as L-theanine dosage increased.Ultimately,the results of this study show that supplementing dairy cow diet with L-theanine could decrease dairy cow rectal temperature,affect lipid metabolism,and potentially relieve the heat stress of dairy cows to some extent.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.32302764)Hunan Provincial Natural Science Foundation(Grant No.2024JJ5179)+1 种基金Key laboratory for the feed and biology technique of Xinjiang Uygur Autonomous Region(Grant No.XJSLSW-2023001)Hunan Herbivores Industry Technological System(Grant No.HARS-08)。
文摘Background Zearalenone(ZEN),a common mycotoxin in ruminant diets,could disturb the rumen ecosystem and impair rumen fermentation.Noticeably,ZEN has been shown to reduce the relative abundances of specific bacterial taxa that potentially possess quorum sensing(QS)functions,which are deemed essential for the microbial interactions and adaptations during rumen fermentation.Nonetheless,whether QS communications participate in the responses of rumen microbial fermentation to ZEN remains unknown.Therefore,the present trial was performed to explore the potential roles of QS during the alterations of rumen microbial fermentation by ZEN through a rumen simulation technique(RUSITEC)system,in a replicated 4×4 Latin square design.Results ZEN significantly(P<0.05)reduced QS signal autoinducer-2(AI-2),and tended to(P=0.051)downregulate QS signal C4-homoserine lactone(HSL).ZEN also significantly(P<0.05)decreased total volatile fatty acid(TVFA),acetate,propionate,isobutyrate,isovalerate,organic matter disappearance(OMD),neutral detergent fiber disappearance(NDFD),and acid detergent fiber disappearance(ADFD)in different manners.The linear discriminant analysis effect size(LEf Se)analysis indicated significantly(P<0.05)differential enrichments of a series of bacterial taxa such as Butyrivibrio_sp_X503,Rhizobium daejeonense,Hoylesella buccalis,Ezakiella coagulans,Enterococcus cecorum,Ruminococcus_sp_zg-924,Polystyrenella longa,and Methylacidimicrobium fagopyrum across different treatments.The phylogenetic investigation of communities by reconstruction of unobserved states 2(PICRUSt2)analysis suggested that QS were predicted to be significantly(P<0.05)affected by ZEN.The metabolomics analysis detected considerable significantly(P<0.05)differing metabolites and implied that ZEN challenge significantly(P<0.05)influenced the indole alkaloid biosynthesis,biosynthesis of alkaloids derived from shikimate pathway,and sesquiterpenoid and triterpenoid biosynthesis.Significant(P<0.05)interconnections of QS molecules with the differential rumen fermentation traits,differential bacterial taxa,and differential metabolites were exhibited by Spearman analysis.Conclusions ZEN negatively affected the QS signals of AI-2 and C4-HSL,which was found to correlate with the fluctuations in specific rumen fermentation characteristics,ruminal bacterial populations,and ruminal metabolisms.These interrelationships implied the potential involvement of QS in the reactions of rumen microbiota to ZEN contamination,and probably contributed to the inhibition of rumen fermentation.
基金supported by the National Key R&D Program(Grant No.2022YFD1301101-1)National Natural Science Foundation of China(Grant No.32172758)Key Research and Development Program of Ningxia(Grant No.2024BBF01008)。
文摘Background In this study,the effects of L-leucine(Leu)on rumen fermentation parameters,rumen epithelium development,amino acid composition,rumen bacterial communities and rumen metabolites in beef cattle were investigated.Twenty-four fattening Angus females of similar initial weight(575.5±22.1 kg)were randomly assigned to 2 treatments with 4 replicate pens(3 cattle per pen).They were fed either a basal diet or a basal diet supplemented with 6.0 g L-Leu/100 kg BW/d for 120 d.Results(1)Leu increased the ruminal concentrations of total volatile fatty acid(VFA)(P=0.017),propionate(P=0.023),isovalerate(P=0.001),and branched-chain volatile fatty acid(BCVFA)(P=0.01)at 4 h post-feeding.It also tended to increase acetate(P=0.083)and decrease the ammonia-N(NH_3-N)concentration(P=0.055),but it did not affect ruminal pH(P>0.1).Leu also increased microbial crude protein(MCP)(P=0.026)at 4 h post-feeding,but decreased MCP at 8 h post-feeding(P=0.010).(2)Supplementation with L-Leu increased the ruminal concentrations of phenylalanine(P=0.011),lysine(P=0.034),and tyrosine(P=0.033),while decreasing the cystine concentration(P=0.010).(3)Leu increased the thickness of the stratum spinosum and basal(P<0.05),while decreasing the thickness of the stratum granulosum(P<0.05).(4)Leu upregulated the relative mRNA abundance of genes involved in tight junction proteins(P<0.05)and VFA absorption and metabolism(P<0.01)in the rumen epithelium.This upregulation was positively correlated with the concentrations ruminal isovalerate and BCVFA(P<0.01).(5)L-Leu did not affect the diversity and richness of ruminal microbes(P>0.05),but differential bacterial biomarkers(LEfSe,LDA>2)were either positively or negatively correlated with ruminal MCP,NH_3-N,and BCVFA concentrations(P<0.001).Additionally,differential bacterial metabolites(OPLS-DA,VIP>1.5)were primarily enriched in the amino acid metabolism pathway and the cofactors and vitamins metabolism pathway(P<0.05).Conclusions Dietary supplementation with L-Leu altered rumen fermentation parameters and patterns,improved rumen epithelial morphology,and enhanced the expression of genes related to VFA absorption and metabolism in the rumen epithelium of beef cattle.
文摘The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR ) is an essential enzyme in cholesterol biosynthesis. To study the expression of HMGR in adipose and muscle tissues, and some performance indexes of four age stages, twelve Lilu cattle were selected. The results indicated that the Lilu beef cattle have good production and slaughter performance. HMGR mRNA expression level in adipose was higher than in muscle, but the trend in adipose was the same as in muscle. HMGR mRNA expression is difference in adipose and muscle tissues suggesting this gene is expressed in a tissue-dependent manner in cattle. Understanding the causes of variation in HMGR gene expression may provide crucial information about cholesterol biosynthesis in Lilu beef cattle.
基金supported by the Research and demonstration of key Technologies for low-cost,healthy and Efficient Beef Cattle breeding(Grant No.2024BBF01008)National Natural Science Foundation of China(Grant No.32302764)Hunan Provincial Natural Science Foundation(Grant No.2024JJ5179).
文摘This study was to evaluate how low phosphorus(P)diets affect growth performance and fecal P excretion in Xia-Nan cattle and to elucidate the underlying mechanisms.Thirty-two healthy Xia-Nan bulls with similar body weights(BW;267.42±45.77 kg)were assigned to four groups with eight individual replicate pens per group in a completely randomized block design,stratified by initial BW and average dry matter intake(DMI).Cattle were fed total mixed rations(concentrate-to-forage ratio 40:60)with varying dietary P levels(DM basis):0.16%(XPA),0.19%(XPB),0.22%(XPC),and 0.25%(XPD;control)for 90 d.The first three groups were considered low-P treatments.Compared with the XPD group,XPA showed significantly lower average daily gain(ADG;P=0.018)and DMI(P=0.046),while XPB and XPC showed no differences(P>0.05).XPB group showed a significant lower feed conversion ratio(FCR)than XPA(P=0.049)and had the lowest FCR among all groups.Total-tract apparent digestibility of calcium(Ca;P=0.006)and P(P=0.006)decreased linearly with dietary P reduction.P intake(P<0.001)and fecal P content(P<0.001)were significantly lower in low-P groups than in the XPD group and decreased linearly with P reduction.Serum concentrations of parathormone hormone(PTH;P<0.001),1,25-dihydroxyvitamin D_(3)(1,25(OH)_(2)D_(3);P=0.005),Ca(P<0.001),and P(P<0.001)were positively correlated with decreasing dietary P levels,whereas calcitonin(CT;P=0.016)and alkaline phosphatase(ALP;P=0.006)were negatively correlated.XPB and XPD groups had higher molar proportions of propionate(P<0.001)and butyrate(P=0.006)but lower acetate molar proportion(P<0.001)and acetate-to-propionate ratio(P<0.001)than XPA.Fecal P excretion correlated positively with Ruminococcaceae_UCG-005,Saccharofermentans,and Butyrivibrio,and negatively with Rikenellaceae_RC9_gut_group and uncultured_bacteriumf_F082.These results suggest that reducing dietary P to 0.19%(XPB)maintained optimal growth performance while reducing environmental P pollution in XiaNan cattle.
基金supported by the Science and Technology Innovation Team of Hunan Province(2021RC4060)the National Key Research and Development Program of China(2022YFD13011011)A Project Supported by Scientific Research Fund of Hunan Provincial Education Department(21B0185)。
文摘Grape peel,as the by-product of grape wine,is rich in phenolic and proanthocyanidins.Obesity has become a serious global public health problem and supplementation of grape peel phenolics(GPP)may be an effective intervention method.From a dietary nutrition perspective,this study aims to investigate the effects of GPP on improving intestinal barrier function in high-fat diet-treated mice,and further explore the potential mechanism.The results showed that GPP supplementation obviously reduced body weight of mice,increased the abundance of beneficial bacteria(Akkermansia,g_Lachnospiraceae_NK4A136_group,Bacteroidetes and g_norank_f_Muribaculaceae),reduced the relative abundance of harmful bacteria(g_Coriobacteriaceae_UCG-002,g_Dubosiella and Romboutsia).Meanwhile,GPP could alleviate colonic barrier inflammation,facilitate the production of short-chain fatty acids and secondary bile acids,increase the mRNA and protein expression levels of intestinal tight junction proteins,and protect intestinal barrier integrity,especially in the LGPP group(100 mg/kg·day GPP).Kyoto Encyclopedia of Genes and Genomes analysis on fecal metabolism indicated that GPP could effectively alleviate intestinal imbalance caused by obesity through targeting multiple shared pathways.Bile secretion and arachidonic acid are the key differential metabolic pathways,and 14 key differential metabolites were identified.In conclusion,GPP supplementation has the potential to alleviate obesity by regulating gut microbiota,improving gut barrier integrity,and modulating the related metabolites.
基金the funding through the Hunan Provincial Natural Science Foundation(Grant No.2019JJ50279,2019RS3021)Hunan Provincial Education Department(Grant No.19B257)+2 种基金Hunan Provincial Science and Technology Department(Grant No.2017NK1020)Ministry of Science and Technology of China(Grant No.2018YFD0501604)National Natural Science Foundation of China(Grant No.31772633)。
文摘The present trial was performed to reveal the regulatory effects of L-theanine on the levels of lipopolysaccharide(LPS)endotoxin within different biofluids,as well as relevant inflammatory responses of dairy cattle under heat stress conditions.Thirty lactating Chinese Holstein dairy cattle(189±47 d in milk,and 2±1 parities)were allocated in a completely randomized design to each of 3 dietary treatments:the control(CON,0 g/d per cow L-theanine),the low L-theanine dosage treatment(LL,16 g/d per cow L-theanine),and the high L-theanine dosage treatment(HL,32 g/d per cow L-theanine).This trial consisted of 38 d(7 d for adaption and 31 d for data and sample collection),and sample collection for rumen liquid,blood plasma or serum,and milk were conducted on the d 27 and 38,respectively.Dairy cattle were constantly exposed to environmental heat stress during this experiment according to the recorded temperature-humidity index(THI).In the LL treatment,LPS concentration in rumen liquid was higher(P<0.05),whilst LPS densities in plasma and milk were lower(P<0.05)than those of the CON.Supplementing L-theanine at 2 dosages both significantly lowered(P<0.05)the level of interleukin(IL)-1βin the serum.Results of the present study suggested that L-theanine could be a promising additive in reducing the detrimental effects of heat stress on dairy cows,and L-theanine supplementation at 16 g/d per cow is preferred because it reduced the LPS translocation into the peripheral blood and LPS accumulation in the milk,as well as mitigated LPS-induced inflammatory reactions in dairy cows during heat stress.Further studies are necessitated to investigate the underlying mechanisms of L-theanine in LPS alteration and inflammation alleviation.
基金financially supported by National Key Research and Development Program(Grant No.2018YFD0501604)Hunan Provincial Science and Technology Major Project(Grant No.2017NK1020)+3 种基金Hunan Provincial Natural Science Foundation(Grant No.2019JJ50279)The Construction of Innovative in Hunan Province(Grant No.2019RS3021)Hunan Agricultural University(Grant No.17QN09)Effect of secondary metabolites of rapeseed meal on methane emission from goats(Grant No.2019ZDSYS01)。
文摘The purpose of this study was to investigate the effects of dietary L-theanine supplementation on apparent nutrient digestibility,milk yield,milk composition,and blood biochemical indices of dairy cows under heat stress.Thirty Chinese Holstein cows(19.84±2.42 kg milk/d,192.36±40.77 d in milk and2±0.93 parities)were divided into 3 groups of 10 animals each.The control group was fed a basal total mixed ration(TMR)diet,while treatment 1(LTA16)and treatment 2(LTA32)groups were fed a basal TMR diet supplemented with L-theanine at 16 and 32 g/cow per day,respectively.The results showed that feeding the dairy cows with LTA16 treatment decreased(P<0.05)their rectal temperature,whereas feeding with LTA32 treatment decreased(P<0.05)their rumen fluid ammonia nitrogen content.In comparison to the control group,the supplementation of L-theanine had no significant effect(P>0.05)on the dry matter intake,nutrient digestibility,total volatile fatty acid(TVFA)concentration and molar proportion of volatile fatty acid,milk yield,milk composition,feed efficiency and antioxidant capacity of the dairy cows.The triglyceride(TG)content of the LTA32 group was significantly greater(P=0.014)than that of the control group.With the increase in L-theanine dosage,the serum cholesterol(CHOL)content significantly increased(P=0.013).The serum albumin(ALB;P=0.067),low-density lipoprotein cholesterol(LDL-C;P=0.053),and high-density lipoprotein cholesterol(HDL-C;P=0.067)contents showed an upward trend as L-theanine dosage increased.Ultimately,the results of this study show that supplementing dairy cow diet with L-theanine could decrease dairy cow rectal temperature,affect lipid metabolism,and potentially relieve the heat stress of dairy cows to some extent.
