Background:In recent years,nitrooxy compounds have been identified as promising inhibitors of methanogenesis in ruminants.However,when animals receive a nitrooxy compound,a high portion of the spared hydrogen is eruct...Background:In recent years,nitrooxy compounds have been identified as promising inhibitors of methanogenesis in ruminants.However,when animals receive a nitrooxy compound,a high portion of the spared hydrogen is eructated as gas,which partly offsets the energy savings of CH4mitigation.The objective of the present study was to evaluate the long-term and combined effects of supplementation with N-[2-(nitrooxy)ethyl]-3-pyridinecarboxamide(NPD),a methanogenesis inhibitor,and fumaric acid(FUM),a hydrogen sink,on enteric CH4production,rumen fermentation,bacterial populations,apparent nutrient digestibility,and lactation performance of dairy goats.Results:Twenty-four primiparous dairy goats were used in a randomized complete block design with a 2×2factorial arrangement of treatments:supplementation without or with FUM(32 g/d)or NPD(0.5 g/d).All samples were collected every 3 weeks during a 12-week feeding experiment.Both FUM and NPD supplementation persistently inhibited CH4yield(L/kg DMI,by 18.8%and 18.1%,respectively)without negative influence on DMI or apparent nutrient digestibility.When supplemented in combination,no additive CH4suppression was observed.FUM showed greater responses in increasing the molar proportion of propionate when supplemented with NPD than supplemented alone(by 10.2%vs.4.4%).The rumen microbiota structure in the animals receiving FUM was different from that of the other animals,particularly changed the structure of phylum Firmicutes.Daily milk production and serum total antioxidant capacity were improved by NPD,but the contents of milk fat and protein were decreased,probably due to the bioactivity of absorbed NPD on body metabolism.Conclusions:Supplementing NPD and FUM in combination is a promising way to persistently inhibit CH4emissions with a higher rumen propionate proportion.However,the side effects of this nitrooxy compound on animals and its residues in animal products need further evaluation before it can be used as an animal feed additive.展开更多
We investigated phytotoxicity in seven plant species exposed to a range of concentrations (0- 500 mg· kg^-1 soil) of di-n-butyl phthalate (DnBP) or his (2- ethylhexyl) phthalate (DEHP), two representative...We investigated phytotoxicity in seven plant species exposed to a range of concentrations (0- 500 mg· kg^-1 soil) of di-n-butyl phthalate (DnBP) or his (2- ethylhexyl) phthalate (DEHP), two representative phthalate esters (PAEs) nominated by USEPA as priority pollutants and known environmental estrogens. We studied seed germination, root elongation, seedling growth, biomass (fresh weight, FW) and malondialdehyde (MDA) content of shoots and roots of wheat (Triticum aestivum L.), alfalfa (Medicago sativa L.), perennial ryegrass (Lolium perenne), radish (Raphanus sativus L.), cucumber (Cucumis sativus L.), oat (Avena sativa) and onion (Allium cepa L.), together with monitoring of plant pigment content (chlorophyll a, b and earotinoids) in alfalfa, radish and onion shoots. Root elongation, seedling growth and biomass of the test species were generally inhibited by DnBP but not by DEHP, indicating a lower level of phytotoxicity of DEHP than of DnBP. MDA contents of four species were promoted by PAE exposure, but not in alfalfa, ryegrass or onion shoots, indicating lower sensitivity of these three species to PAE pollutants. Plant pigment contents were clearly affected under the stress of both pollutants, implying the potential damage to the photosynthetic system of test plants, mainly by decreasing the content of chlorophyll a and b. Results of DnBP and DEHP phytotoxicity to the primary growth of test plants has provided information for the assessment of their environmental risk in the soil and also forms a basis for the further analysis of their toxic effects over the whole growth period of different plant species.展开更多
We describe a specific procedure for the synthesis of deuterium-labelled 2-(1-methylalkyl)succinate established via alkylation of diethyl malonate, Krapcho decarboxylation reaction with D20 and hydrolysis reaction. ...We describe a specific procedure for the synthesis of deuterium-labelled 2-(1-methylalkyl)succinate established via alkylation of diethyl malonate, Krapcho decarboxylation reaction with D20 and hydrolysis reaction. Two novel compounds, 2-[^2H]-2-ethylsuccinic acid and 2-[^2H]-2-(1-methylhep- tyl)succinic acid were prepared via this synthetic route and characterized by mass spectrometry and ^1H NMR. The results showed that the 2-(1-methylalkyl)succinic acids were deuterated at the β-position, which is considered as an important reaction centre in the anaerobic degradation of n-alkanes.展开更多
基金supported by the National Natural Science Foundation of China(award number:31902126)the Science&Technological Project of Shaanxi Province,China(award number:2017TSCXL-NY-04-01)。
文摘Background:In recent years,nitrooxy compounds have been identified as promising inhibitors of methanogenesis in ruminants.However,when animals receive a nitrooxy compound,a high portion of the spared hydrogen is eructated as gas,which partly offsets the energy savings of CH4mitigation.The objective of the present study was to evaluate the long-term and combined effects of supplementation with N-[2-(nitrooxy)ethyl]-3-pyridinecarboxamide(NPD),a methanogenesis inhibitor,and fumaric acid(FUM),a hydrogen sink,on enteric CH4production,rumen fermentation,bacterial populations,apparent nutrient digestibility,and lactation performance of dairy goats.Results:Twenty-four primiparous dairy goats were used in a randomized complete block design with a 2×2factorial arrangement of treatments:supplementation without or with FUM(32 g/d)or NPD(0.5 g/d).All samples were collected every 3 weeks during a 12-week feeding experiment.Both FUM and NPD supplementation persistently inhibited CH4yield(L/kg DMI,by 18.8%and 18.1%,respectively)without negative influence on DMI or apparent nutrient digestibility.When supplemented in combination,no additive CH4suppression was observed.FUM showed greater responses in increasing the molar proportion of propionate when supplemented with NPD than supplemented alone(by 10.2%vs.4.4%).The rumen microbiota structure in the animals receiving FUM was different from that of the other animals,particularly changed the structure of phylum Firmicutes.Daily milk production and serum total antioxidant capacity were improved by NPD,but the contents of milk fat and protein were decreased,probably due to the bioactivity of absorbed NPD on body metabolism.Conclusions:Supplementing NPD and FUM in combination is a promising way to persistently inhibit CH4emissions with a higher rumen propionate proportion.However,the side effects of this nitrooxy compound on animals and its residues in animal products need further evaluation before it can be used as an animal feed additive.
文摘We investigated phytotoxicity in seven plant species exposed to a range of concentrations (0- 500 mg· kg^-1 soil) of di-n-butyl phthalate (DnBP) or his (2- ethylhexyl) phthalate (DEHP), two representative phthalate esters (PAEs) nominated by USEPA as priority pollutants and known environmental estrogens. We studied seed germination, root elongation, seedling growth, biomass (fresh weight, FW) and malondialdehyde (MDA) content of shoots and roots of wheat (Triticum aestivum L.), alfalfa (Medicago sativa L.), perennial ryegrass (Lolium perenne), radish (Raphanus sativus L.), cucumber (Cucumis sativus L.), oat (Avena sativa) and onion (Allium cepa L.), together with monitoring of plant pigment content (chlorophyll a, b and earotinoids) in alfalfa, radish and onion shoots. Root elongation, seedling growth and biomass of the test species were generally inhibited by DnBP but not by DEHP, indicating a lower level of phytotoxicity of DEHP than of DnBP. MDA contents of four species were promoted by PAE exposure, but not in alfalfa, ryegrass or onion shoots, indicating lower sensitivity of these three species to PAE pollutants. Plant pigment contents were clearly affected under the stress of both pollutants, implying the potential damage to the photosynthetic system of test plants, mainly by decreasing the content of chlorophyll a and b. Results of DnBP and DEHP phytotoxicity to the primary growth of test plants has provided information for the assessment of their environmental risk in the soil and also forms a basis for the further analysis of their toxic effects over the whole growth period of different plant species.
基金supported by the National Natural Science Foundation of China(No.41373070,51174092)the National Natural Science Foundation of China/Research Grants Council Joint Research Fund(No.41161160560)
文摘We describe a specific procedure for the synthesis of deuterium-labelled 2-(1-methylalkyl)succinate established via alkylation of diethyl malonate, Krapcho decarboxylation reaction with D20 and hydrolysis reaction. Two novel compounds, 2-[^2H]-2-ethylsuccinic acid and 2-[^2H]-2-(1-methylhep- tyl)succinic acid were prepared via this synthetic route and characterized by mass spectrometry and ^1H NMR. The results showed that the 2-(1-methylalkyl)succinic acids were deuterated at the β-position, which is considered as an important reaction centre in the anaerobic degradation of n-alkanes.