本试验旨在研究在低粗蛋白质（CP）饲粮中添加甘氨酸（Gly）对肉仔鸡生长性能、胴体组成和血液生化指标的影响。选用180只1日龄健康爱拔益加（AA）肉仔鸡（公雏）,随机分为3组,每组6个重复,每个重复10只。3组分别为：正对照（PC）组,前...本试验旨在研究在低粗蛋白质（CP）饲粮中添加甘氨酸（Gly）对肉仔鸡生长性能、胴体组成和血液生化指标的影响。选用180只1日龄健康爱拔益加（AA）肉仔鸡（公雏）,随机分为3组,每组6个重复,每个重复10只。3组分别为：正对照（PC）组,前期和后期饲粮CP水平分别为22.0%和20.0%;负对照组,前期和后期饲粮CP水平分别为18.0%和15.5%;Gly组,在负对照组基础上添加Gly,使饲粮Gly和丝氨酸水平为2.32%。试验期42 d,分为前期（1-21 d）和后期（22-42 d）2个阶段。结果表明：1）饲粮CP水平降低4.0-4.5个百分点,试验1-21 d的料重比（F/G）显著升高（P〈0.05）,22-42 d的平均日增重（ADG）显著降低（P〈0.05）;添加Gly后,1-21 d F/G显著降低（P〈0.05）,22-42 d ADG显著升高（P〈0.05）,达到了与PC组相似的生长性能。2）CP水平降低,肉仔鸡42日龄胸肌率降低了9.5%（P〈0.05）、腹脂率提高了60.3%（P〈0.05）;添加Gly后,胸肌率提高了17.6%（P〈0.05）,腹脂率降低了34.6%（P〈0.05）,获得了与PC组相似的胴体组成。CP水平降低、添加Gly均未显著影响屠宰率、全净膛率和腿肌率（P〉0.05）。3）各组间血液生化指标均无显著差异（P〉0.05）。可见,低CP饲粮中添加Gly可以改善生长性能和胴体组成,结果提示了Gly在肉仔鸡低CP饲粮中的可应用性。展开更多
Background： To determine responses of neonatal intestine to maternal increased consumption of DL-methionine（DLM） or DL-2-hydroxy-4-methylthiobutanoic acid（HMTBA）, eighteen primiparous sows（Landrace × Yorksh...Background： To determine responses of neonatal intestine to maternal increased consumption of DL-methionine（DLM） or DL-2-hydroxy-4-methylthiobutanoic acid（HMTBA）, eighteen primiparous sows（Landrace × Yorkshire） were allocated based on body weight and backfat thickness to the control, DLM and HMTBA groups（n = 6）, with the nutritional treatments introduced from postpartum d0 to d14.Results： The DLM-fed sows showed negative energy balance manifested by lost bodyweight, lower plasma glucose, subdued tricarboxylic acid cycle, and increased plasma lipid metabolites levels. Both villus height and ratio of villus height to crypt depth averaged across the small intestine of piglets were higher in the DLM and HMTBA groups than in the control group. Piglet jejunal oxidized glutathione concentration and ratio of oxidized to reduced glutathione were lower in the HMTBA group than in the DLM and control groups. However, piglet jejunal aminopeptidase A, carnitine transporter 2 and IGF-II precursor m RNA abundances were higher in the DLM group than in the HMTBA and control groups.Conclusion： Increasing maternal consumption of methionine as DLM and HMTBA promoted neonatal intestinal growth by increasing morphological development or up-regulating expression of genes responsible for nutrient metabolism. And increasing maternal consumption of HMTBA promoted neonatal intestinal antioxidant capacity without compromising maternal energy homeostasis during early lactation.展开更多
Diet is a major modulator of animal resilience and its three pillars:host's immune response,gut microbiota,and intestinal barrier.In the present study,we endeavour to delineate a challenging con-dition aimed to de...Diet is a major modulator of animal resilience and its three pillars:host's immune response,gut microbiota,and intestinal barrier.In the present study,we endeavour to delineate a challenging con-dition aimed to degrade these pillars and elucidate its impact on broiler performance and nutrient di-gestibility.To attain this objective,we opted to use guar gum(GG)as a source of galactomannan.A series of three in vivo experiments were conducted employing conventional or semi-purified diets,supple-mented with or without GG during the grower phase(14-28 d).Our findings demonstrate a substantial decline in animal performance metrics such as body weight(reduced by 29%,P<0.001),feed intake(decreased by 12%,P<0.001),and feed conversion ratio(up to 58%increase,P<0.001)in the presence of GG at 2%.The supplementation of a semi-purified diet with incremental doses of GG resulted in a linear reduction(P<0.001)in the apparent total tract digestibility of dry matter and apparent metabolisable energy.Additionally,a marked reduction in ileal endogenous losses,as well as apparent and standardised digestibility of all amino acids with varying proportions(P<0.05),was observed.These alterations were accompanied by disrupted gut integrity assessed by fluorescein isothiocyanate-dextran(FITC-d)(P<0.001)as well as an inflammatory status characterised by elevated levels of acute-phase proteins,namely orosomucoid and serum amyloid A in the sera(P=0.03),and increased mRNA expression levels of IL-1,IL-6,IL-8,Inos,and K203 genes in the ileum,along with a decrease in IgA levels in the gut lumen(P<0.05).Microbial ecology and activity were characterised by reduced diversity and richness(Shannon index,P=0.005)in the presence of GG.Consequently,our results revealed diminished levels of short-chain fatty acids(P=0.01)and their producer genera,such as Clostridium_XIVa and Blautia,in the gut caeca,coupled with excessive accumulation of lactate(17-fold increase,P<0.01)in the presence of GG at 2%.In addition to providing a more comprehensive characterisation of the GG supplementation as a leaky gut model,our results substantiate a thorough understanding of the intricate adjustments and interplay between the intestinal barrier,immune response,and microbiota.Furthermore,they underscore the significance of feed components in modulating these dynamics.展开更多
This experiment aimed to study the effects of supplemental methionine sources,2-hydroxy-4 methyl(thio)butanoic acid(HMTBa)and DL-Methionine(DL-Met),on productive performance,egg quality,and redox status of laying duck...This experiment aimed to study the effects of supplemental methionine sources,2-hydroxy-4 methyl(thio)butanoic acid(HMTBa)and DL-Methionine(DL-Met),on productive performance,egg quality,and redox status of laying ducks.A total of 792 healthy 25-wk-old Longyan laying ducks with similar body weights were randomly allotted to 11 treatment groups.Each treatment group had 6 replicates of 12 ducks.The trial lasted for 16 wk.Ducks were fed a basal deficient diet(Met:0.24%;Met+Cys:0.51%)or supplemented with DL-Met or HMTBa at 0.05%,0.12%,0.19%,0.26%,and 0.33%of diet,respectively.Compared with the basal diet,supplementation with either DL-Met or HMTBa increased the average egg weight,egg mass,and decreased feed to egg ratio during the whole trial period(P<0.05).Albumen weight and its ratio to total egg weight were increased,but yolk and shell ratio,albumen height,Haugh unit and shell breaking strength were decreased(P<0.05).Dietary DL-Met or HMTBa supplementation increased taurine,methionine,leucine,tryptophan and arginine content,and decreased serine and lysine content in plasma(P<0.05).The redox status of laying ducks was improved by enhancing the glutathione peroxidase and catalase activities,glutathione content and its ratio relative to glutathione(oxidized)content and decreasing malondialdehyde content and increasing mRNA expression of superoxide dismutase-1,glutathione peroxidase-1,hemeoxygenase-1 and nuclear factor-like 2 in liver and ileum with the supplementation of DL-Met or HMTBa(P<0.05).Liver health status measured by average area proportion lipid droplet was improved with supplementation of DL-Met or HMTBa(P<0.05).Villus height and villus height to crypt depth ratio in the ileum and the ileal gene expression of tight junction protein and occludin were increased with DL-Met or HMTBa supplementation(P<0.05).Taken together,these results suggested that the efficacy of dietary supplementation of HMTBa was similar to DL-Met,and it ranged from 98%to 100%for productive performance and egg albumen ratio in laying ducks(25 to 41 wk).展开更多
This literature review evaluates the absorption of methionine (Met) sources such as 2-hydroxy-4-methylthiobutyric acid (HMTBa), its calcium salts (HMTBa-Ca), and DL-methionine (DL-Met) by focusing on the state of know...This literature review evaluates the absorption of methionine (Met) sources such as 2-hydroxy-4-methylthiobutyric acid (HMTBa), its calcium salts (HMTBa-Ca), and DL-methionine (DL-Met) by focusing on the state of knowledge regarding the absorption mechanism, experimental methodology, and factors affecting their absorption. The 2 Met sources differ in mechanism and site of absorption due to differences in their chemical characteristics and enzymatic conversion. This review addresses diffusion- and transport-mediated absorption systems for amino acids and carboxylic compounds, best elucidated by in vitro, ex vivo, and in vivo experimental models. Opportunities and limitations in the use of radioisotopes to depict absorption sites as well as host and microbial metabolism are described. Physiological and environmental conditions that lead to changes in gut absorptive capacity and the impact of Met source absorption are also evaluated. This review concludes that any comparison between HMTBa and DL-Met should consider their different behaviors during the absorption phase. Hence, the chemical characteristics of these 2 molecules entail different absorption sites and mechanisms, from passive absorption in the case of HMTBa and HMTBa-Ca to active transporters for DL-Met, HMTBa, and HMTBa-Ca. In addition, the different conversion modes of these 2 molecules further differentiate their absorption modes. Considering these important differences, it is easier to understand the apparent divergence between the conclusions of existing publications. When comparing these 2 molecules, it is recommended to properly adapt to the conditions under which the absorption of Met sources is evaluated.展开更多
The goal of this review article,based on a systematic literature search,is to critically assess the state of knowledge and experimental methodologies used to delineate the conversion and metabolism of the 2 methionine...The goal of this review article,based on a systematic literature search,is to critically assess the state of knowledge and experimental methodologies used to delineate the conversion and metabolism of the 2 methionine(Met)sources DL-methionine(DL-Met)and DL-2-hydroxy-4-(methylthio)butanoic acid(HMTBa).The difference in the chemical structures of HMTBa and DL-Met indicates that these molecules are absorbed and metabolized differently in animals.This review explores the methodologies used to describe the 2-step enzymatic conversion of the 3 enantiomers(D-HMTBa,L-HMTBa and D-Met)to L-Met,as well as the site of conversion at the organ and tissue levels.Extensive work was published documenting the conversion of HMTBa and D-Met into L-Met and,consequently,the incorporation into protein using a variety of in vitro techniques,such as tissue homogenates,cell lines,primary cell lines,and everted gut sacs of individual tissues.These studies illustrated the role of the liver,kidney,and intestine in the con-version of Met precursors into L-Met.A combination of in vivo studies using stable isotopes and infusions provided evidence of the wide conversion of HMTBa to L-Met by all tissues and how some tissues are net users of HMTBa,whereas others are net secreters of L-Met derived from HMTBa.Conversion of D-Met to L-Met in organs other than the liver and kidney is poorly documented.The methodology cited in the literature to determine conversion efficiency ranged from measurements of urinary,fecal,and respiratory excretion to plasma concentration and tissue incorporation of isotopes after intraperitoneal and oral in-fusions.Differences observed between these methodologies reflect differences in the metabolism of Met sources rather than differences in conversion efficiency.The factors affecting conversion efficiency are explored in this paper and are mostly associated with extreme dietary conditions,such as noncommercial crystalline diets that are very deficient in total sulfur amino acids with respect to requirements.Impli-cations in the diversion of the 2 Met sources toward transsulfuration over transmethylation pathways are discussed.The strengths and weaknesses of some methodologies used are discussed in this review.From this review,it can be concluded that due to the inherent differences in conversion and metabolism of the 2 Met sources,the experimental methodologies(e.g.,selecting different organs at different time points or using diets severely deficient in Met and cysteine)can impact the conclusions of the study and may explain the apparent divergences of conclusion found in the literature.It is recommended when con-ducting studies or reviewing the literature to properly select the experimental models that allow for differences in how the 2 Met precursors are converted to L-Met and metabolized by the animal to enable a proper comparison of their bioefficacy.展开更多
Given the key role of methionine in biological processes,adequate methionine should be provided to meet the nutritional requirements.DL-2-hydroxy-4-(methylthio)-butanoic acid(DL-HMTBA)has been considered as an importa...Given the key role of methionine in biological processes,adequate methionine should be provided to meet the nutritional requirements.DL-2-hydroxy-4-(methylthio)-butanoic acid(DL-HMTBA)has been considered as an important source of methionine.However,the effects of different sources and levels of methionine on the intestinal health status have not been clarified yet.An experiment was carried out to investigate the effects of different dietary sources and levels of methionine on the intestinal epithelial barrier,inflammatory cytokines expression,ileal morphology,microbiota composition,and cecal short chain fatty acids(SCFA)profiles.For this purpose,720 male Arbor Acre broiler chicks at 1 d old were randomly assigned to a 2×3 factorial arrangement with 2 methionine sources(DL-methionine and DLHMTBA)and 3 total sulfur amino acids(TSAA)levels(80%,100%,and 120%of Arbor Acre recommendation).The results showed that DL-HMTBA supplementation promoted intestinal physical barrier at both gene expression level of claudin-1 and serum diamine oxidase level(P<0.05),and the inflammatory cytokine IL-6 m RNA expression was down-regulated by dietary DL-HMTBA supplementation compared with the DL-methionine group(P<0.05).Meanwhile,an upregulated gene expression of claudin-1 and zonula occluden-1(ZO-1)were observed in the low-TSAA treatment on d 14(P<0.05),whereas this treatment increased the expression of IL-1βand IL-6(P<0.05).Villus height to crypt depth ratio was high(P<0.05)in the middle-level TSAA group.Furthermore,DL-HMTBA supplementation optimized the microbiota of the ileum especially the relative abundance of Lactobacillus,where the digestion and absorption were completed,and elevated the concentrations of SCFA(acetate,propionate,and butyrate)in the cecal content on d 21(P<0.01).In conclusion,dietary DL-HMTBA supplementation improved the intestinal barrier function,immune homeostasis and optimized the microbiota to promote intestinal health status in broiler chickens.展开更多
Our publication on absorption of methionine sources(Becquet et al.,2023a)is a thorough analysis of 129 references dealing with absorption of sources of methionine,with the objective to critically evaluate the methodol...Our publication on absorption of methionine sources(Becquet et al.,2023a)is a thorough analysis of 129 references dealing with absorption of sources of methionine,with the objective to critically evaluate the methodologies used and their impact on the conclusions of the studies.As the focus of our publicationwas on the evaluation of absorption,efficacy studies and reports not having information on absorption were not considered(Elwert et al.,2008;Rychen et al.,2008).展开更多
文摘本试验旨在研究在低粗蛋白质（CP）饲粮中添加甘氨酸（Gly）对肉仔鸡生长性能、胴体组成和血液生化指标的影响。选用180只1日龄健康爱拔益加（AA）肉仔鸡（公雏）,随机分为3组,每组6个重复,每个重复10只。3组分别为：正对照（PC）组,前期和后期饲粮CP水平分别为22.0%和20.0%;负对照组,前期和后期饲粮CP水平分别为18.0%和15.5%;Gly组,在负对照组基础上添加Gly,使饲粮Gly和丝氨酸水平为2.32%。试验期42 d,分为前期（1-21 d）和后期（22-42 d）2个阶段。结果表明：1）饲粮CP水平降低4.0-4.5个百分点,试验1-21 d的料重比（F/G）显著升高（P〈0.05）,22-42 d的平均日增重（ADG）显著降低（P〈0.05）;添加Gly后,1-21 d F/G显著降低（P〈0.05）,22-42 d ADG显著升高（P〈0.05）,达到了与PC组相似的生长性能。2）CP水平降低,肉仔鸡42日龄胸肌率降低了9.5%（P〈0.05）、腹脂率提高了60.3%（P〈0.05）;添加Gly后,胸肌率提高了17.6%（P〈0.05）,腹脂率降低了34.6%（P〈0.05）,获得了与PC组相似的胴体组成。CP水平降低、添加Gly均未显著影响屠宰率、全净膛率和腿肌率（P〉0.05）。3）各组间血液生化指标均无显著差异（P〉0.05）。可见,低CP饲粮中添加Gly可以改善生长性能和胴体组成,结果提示了Gly在肉仔鸡低CP饲粮中的可应用性。
基金financially support from the Rhodimet Research Grant from Adisseo France S.A.S.,Briand,Antony Cedex,Francethe National Natural Science Fundation of China(31472109)+2 种基金Sichuan Province Science Foundation for Fostering Youths Talents(2011JQ0015)Program for Changjiang Scholars and Innovative Research Team in University(IRT13083)All sources of funding were involved in the design of the study and collection,analysis,and interpretation of data and in writing the manuscript
文摘Background： To determine responses of neonatal intestine to maternal increased consumption of DL-methionine（DLM） or DL-2-hydroxy-4-methylthiobutanoic acid（HMTBA）, eighteen primiparous sows（Landrace × Yorkshire） were allocated based on body weight and backfat thickness to the control, DLM and HMTBA groups（n = 6）, with the nutritional treatments introduced from postpartum d0 to d14.Results： The DLM-fed sows showed negative energy balance manifested by lost bodyweight, lower plasma glucose, subdued tricarboxylic acid cycle, and increased plasma lipid metabolites levels. Both villus height and ratio of villus height to crypt depth averaged across the small intestine of piglets were higher in the DLM and HMTBA groups than in the control group. Piglet jejunal oxidized glutathione concentration and ratio of oxidized to reduced glutathione were lower in the HMTBA group than in the DLM and control groups. However, piglet jejunal aminopeptidase A, carnitine transporter 2 and IGF-II precursor m RNA abundances were higher in the DLM group than in the HMTBA and control groups.Conclusion： Increasing maternal consumption of methionine as DLM and HMTBA promoted neonatal intestinal growth by increasing morphological development or up-regulating expression of genes responsible for nutrient metabolism. And increasing maternal consumption of HMTBA promoted neonatal intestinal antioxidant capacity without compromising maternal energy homeostasis during early lactation.
文摘Diet is a major modulator of animal resilience and its three pillars:host's immune response,gut microbiota,and intestinal barrier.In the present study,we endeavour to delineate a challenging con-dition aimed to degrade these pillars and elucidate its impact on broiler performance and nutrient di-gestibility.To attain this objective,we opted to use guar gum(GG)as a source of galactomannan.A series of three in vivo experiments were conducted employing conventional or semi-purified diets,supple-mented with or without GG during the grower phase(14-28 d).Our findings demonstrate a substantial decline in animal performance metrics such as body weight(reduced by 29%,P<0.001),feed intake(decreased by 12%,P<0.001),and feed conversion ratio(up to 58%increase,P<0.001)in the presence of GG at 2%.The supplementation of a semi-purified diet with incremental doses of GG resulted in a linear reduction(P<0.001)in the apparent total tract digestibility of dry matter and apparent metabolisable energy.Additionally,a marked reduction in ileal endogenous losses,as well as apparent and standardised digestibility of all amino acids with varying proportions(P<0.05),was observed.These alterations were accompanied by disrupted gut integrity assessed by fluorescein isothiocyanate-dextran(FITC-d)(P<0.001)as well as an inflammatory status characterised by elevated levels of acute-phase proteins,namely orosomucoid and serum amyloid A in the sera(P=0.03),and increased mRNA expression levels of IL-1,IL-6,IL-8,Inos,and K203 genes in the ileum,along with a decrease in IgA levels in the gut lumen(P<0.05).Microbial ecology and activity were characterised by reduced diversity and richness(Shannon index,P=0.005)in the presence of GG.Consequently,our results revealed diminished levels of short-chain fatty acids(P=0.01)and their producer genera,such as Clostridium_XIVa and Blautia,in the gut caeca,coupled with excessive accumulation of lactate(17-fold increase,P<0.01)in the presence of GG at 2%.In addition to providing a more comprehensive characterisation of the GG supplementation as a leaky gut model,our results substantiate a thorough understanding of the intricate adjustments and interplay between the intestinal barrier,immune response,and microbiota.Furthermore,they underscore the significance of feed components in modulating these dynamics.
基金supported by the China Agricultural Research System(CARS-42-K13)Modern Agricultural Industry Technology System Innovation Team of Guangdong Province(2022KJ137)+2 种基金Adisseo France S.A.S.(20201020112CN)Young S&T Talent Training Program of Guangdong Provincial Association for S&T(SKXRC202213)Special fund for scientific innovation strategyconstruction of high-level Academy of Agriculture Science(202106TD,R2021PY-QY005)。
文摘This experiment aimed to study the effects of supplemental methionine sources,2-hydroxy-4 methyl(thio)butanoic acid(HMTBa)and DL-Methionine(DL-Met),on productive performance,egg quality,and redox status of laying ducks.A total of 792 healthy 25-wk-old Longyan laying ducks with similar body weights were randomly allotted to 11 treatment groups.Each treatment group had 6 replicates of 12 ducks.The trial lasted for 16 wk.Ducks were fed a basal deficient diet(Met:0.24%;Met+Cys:0.51%)or supplemented with DL-Met or HMTBa at 0.05%,0.12%,0.19%,0.26%,and 0.33%of diet,respectively.Compared with the basal diet,supplementation with either DL-Met or HMTBa increased the average egg weight,egg mass,and decreased feed to egg ratio during the whole trial period(P<0.05).Albumen weight and its ratio to total egg weight were increased,but yolk and shell ratio,albumen height,Haugh unit and shell breaking strength were decreased(P<0.05).Dietary DL-Met or HMTBa supplementation increased taurine,methionine,leucine,tryptophan and arginine content,and decreased serine and lysine content in plasma(P<0.05).The redox status of laying ducks was improved by enhancing the glutathione peroxidase and catalase activities,glutathione content and its ratio relative to glutathione(oxidized)content and decreasing malondialdehyde content and increasing mRNA expression of superoxide dismutase-1,glutathione peroxidase-1,hemeoxygenase-1 and nuclear factor-like 2 in liver and ileum with the supplementation of DL-Met or HMTBa(P<0.05).Liver health status measured by average area proportion lipid droplet was improved with supplementation of DL-Met or HMTBa(P<0.05).Villus height and villus height to crypt depth ratio in the ileum and the ileal gene expression of tight junction protein and occludin were increased with DL-Met or HMTBa supplementation(P<0.05).Taken together,these results suggested that the efficacy of dietary supplementation of HMTBa was similar to DL-Met,and it ranged from 98%to 100%for productive performance and egg albumen ratio in laying ducks(25 to 41 wk).
文摘This literature review evaluates the absorption of methionine (Met) sources such as 2-hydroxy-4-methylthiobutyric acid (HMTBa), its calcium salts (HMTBa-Ca), and DL-methionine (DL-Met) by focusing on the state of knowledge regarding the absorption mechanism, experimental methodology, and factors affecting their absorption. The 2 Met sources differ in mechanism and site of absorption due to differences in their chemical characteristics and enzymatic conversion. This review addresses diffusion- and transport-mediated absorption systems for amino acids and carboxylic compounds, best elucidated by in vitro, ex vivo, and in vivo experimental models. Opportunities and limitations in the use of radioisotopes to depict absorption sites as well as host and microbial metabolism are described. Physiological and environmental conditions that lead to changes in gut absorptive capacity and the impact of Met source absorption are also evaluated. This review concludes that any comparison between HMTBa and DL-Met should consider their different behaviors during the absorption phase. Hence, the chemical characteristics of these 2 molecules entail different absorption sites and mechanisms, from passive absorption in the case of HMTBa and HMTBa-Ca to active transporters for DL-Met, HMTBa, and HMTBa-Ca. In addition, the different conversion modes of these 2 molecules further differentiate their absorption modes. Considering these important differences, it is easier to understand the apparent divergence between the conclusions of existing publications. When comparing these 2 molecules, it is recommended to properly adapt to the conditions under which the absorption of Met sources is evaluated.
文摘The goal of this review article,based on a systematic literature search,is to critically assess the state of knowledge and experimental methodologies used to delineate the conversion and metabolism of the 2 methionine(Met)sources DL-methionine(DL-Met)and DL-2-hydroxy-4-(methylthio)butanoic acid(HMTBa).The difference in the chemical structures of HMTBa and DL-Met indicates that these molecules are absorbed and metabolized differently in animals.This review explores the methodologies used to describe the 2-step enzymatic conversion of the 3 enantiomers(D-HMTBa,L-HMTBa and D-Met)to L-Met,as well as the site of conversion at the organ and tissue levels.Extensive work was published documenting the conversion of HMTBa and D-Met into L-Met and,consequently,the incorporation into protein using a variety of in vitro techniques,such as tissue homogenates,cell lines,primary cell lines,and everted gut sacs of individual tissues.These studies illustrated the role of the liver,kidney,and intestine in the con-version of Met precursors into L-Met.A combination of in vivo studies using stable isotopes and infusions provided evidence of the wide conversion of HMTBa to L-Met by all tissues and how some tissues are net users of HMTBa,whereas others are net secreters of L-Met derived from HMTBa.Conversion of D-Met to L-Met in organs other than the liver and kidney is poorly documented.The methodology cited in the literature to determine conversion efficiency ranged from measurements of urinary,fecal,and respiratory excretion to plasma concentration and tissue incorporation of isotopes after intraperitoneal and oral in-fusions.Differences observed between these methodologies reflect differences in the metabolism of Met sources rather than differences in conversion efficiency.The factors affecting conversion efficiency are explored in this paper and are mostly associated with extreme dietary conditions,such as noncommercial crystalline diets that are very deficient in total sulfur amino acids with respect to requirements.Impli-cations in the diversion of the 2 Met sources toward transsulfuration over transmethylation pathways are discussed.The strengths and weaknesses of some methodologies used are discussed in this review.From this review,it can be concluded that due to the inherent differences in conversion and metabolism of the 2 Met sources,the experimental methodologies(e.g.,selecting different organs at different time points or using diets severely deficient in Met and cysteine)can impact the conclusions of the study and may explain the apparent divergences of conclusion found in the literature.It is recommended when con-ducting studies or reviewing the literature to properly select the experimental models that allow for differences in how the 2 Met precursors are converted to L-Met and metabolized by the animal to enable a proper comparison of their bioefficacy.
基金This work has been supported by Adisseo France S.A.S(202104810410901)China Agriculture Research System Program(CA RS-41).
文摘Given the key role of methionine in biological processes,adequate methionine should be provided to meet the nutritional requirements.DL-2-hydroxy-4-(methylthio)-butanoic acid(DL-HMTBA)has been considered as an important source of methionine.However,the effects of different sources and levels of methionine on the intestinal health status have not been clarified yet.An experiment was carried out to investigate the effects of different dietary sources and levels of methionine on the intestinal epithelial barrier,inflammatory cytokines expression,ileal morphology,microbiota composition,and cecal short chain fatty acids(SCFA)profiles.For this purpose,720 male Arbor Acre broiler chicks at 1 d old were randomly assigned to a 2×3 factorial arrangement with 2 methionine sources(DL-methionine and DLHMTBA)and 3 total sulfur amino acids(TSAA)levels(80%,100%,and 120%of Arbor Acre recommendation).The results showed that DL-HMTBA supplementation promoted intestinal physical barrier at both gene expression level of claudin-1 and serum diamine oxidase level(P<0.05),and the inflammatory cytokine IL-6 m RNA expression was down-regulated by dietary DL-HMTBA supplementation compared with the DL-methionine group(P<0.05).Meanwhile,an upregulated gene expression of claudin-1 and zonula occluden-1(ZO-1)were observed in the low-TSAA treatment on d 14(P<0.05),whereas this treatment increased the expression of IL-1βand IL-6(P<0.05).Villus height to crypt depth ratio was high(P<0.05)in the middle-level TSAA group.Furthermore,DL-HMTBA supplementation optimized the microbiota of the ileum especially the relative abundance of Lactobacillus,where the digestion and absorption were completed,and elevated the concentrations of SCFA(acetate,propionate,and butyrate)in the cecal content on d 21(P<0.01).In conclusion,dietary DL-HMTBA supplementation improved the intestinal barrier function,immune homeostasis and optimized the microbiota to promote intestinal health status in broiler chickens.
基金supported by Fondo di Ateneo per la Ricerca 2019 FAR2019MARONGIU-Studio di sistemi alternativi di gestione della fase riproduttiva rispettosi della fisiologia e del benessere della coniglia-of University of Sassari。
文摘Our publication on absorption of methionine sources(Becquet et al.,2023a)is a thorough analysis of 129 references dealing with absorption of sources of methionine,with the objective to critically evaluate the methodologies used and their impact on the conclusions of the studies.As the focus of our publicationwas on the evaluation of absorption,efficacy studies and reports not having information on absorption were not considered(Elwert et al.,2008;Rychen et al.,2008).
