This paper reports on the use of APSIM - Maize for retrospective analysis of performance of a high input, high yielding maize crop and analysis of predicted performance of maize grown with high inputs over the long-term (>100 years) for specified scenarios of environmental conditions (temperature and radiation) and agronomic inputs (sowing date, plant population, nitrogen fertiliser and irrigation) at Boort, Victoria, Australia. It uses a high yielding (17 400 kg/ha dry grain, 20 500 kg/ha at 15% water) commercial crop grown in 2004-05 as the basis of the study. Yield for the agronomic and environmental conditions of 2004-05 was predicted accurately, giving confidence that the model could be used for the detailed analyses undertaken. The analysis showed that the yield achieved was close to that possible with the conditions and agronomic inputs of 2004-05. Sowing dates during 21 September to 26 October had little effect on predicted yield, except when combined with reduced temperature. Single year and long-term analyses concluded that a higher plant population (11 plants/m2) is needed to optimise yield, but that slightly lower N and irrigation inputs are appropriate for the plant population used commercially (8.4 plants/m2). Also, compared with changes in agronomic inputs increases in temperature and/or radiation had relatively minor effects, except that reduced temperature reduces predicted yield substantially. This study provides an approach for the use of models for both retrospective analysis of crop performance and assessment of long-term variability of crop yield under a wide range of agronomic and environmental conditions.
{"title":"Analysis of high yielding maize production – a study based on a commercial crop","authors":"C. Birch, G. McLean, A. Sawers","doi":"10.1071/EA06103","DOIUrl":"https://doi.org/10.1071/EA06103","url":null,"abstract":"This paper reports on the use of APSIM - Maize for retrospective analysis of performance of a high input, high yielding maize crop and analysis of predicted performance of maize grown with high inputs over the long-term (>100 years) for specified scenarios of environmental conditions (temperature and radiation) and agronomic inputs (sowing date, plant population, nitrogen fertiliser and irrigation) at Boort, Victoria, Australia. It uses a high yielding (17 400 kg/ha dry grain, 20 500 kg/ha at 15% water) commercial crop grown in 2004-05 as the basis of the study. Yield for the agronomic and environmental conditions of 2004-05 was predicted accurately, giving confidence that the model could be used for the detailed analyses undertaken. The analysis showed that the yield achieved was close to that possible with the conditions and agronomic inputs of 2004-05. Sowing dates during 21 September to 26 October had little effect on predicted yield, except when combined with reduced temperature. Single year and long-term analyses concluded that a higher plant population (11 plants/m2) is needed to optimise yield, but that slightly lower N and irrigation inputs are appropriate for the plant population used commercially (8.4 plants/m2). Also, compared with changes in agronomic inputs increases in temperature and/or radiation had relatively minor effects, except that reduced temperature reduces predicted yield substantially. This study provides an approach for the use of models for both retrospective analysis of crop performance and assessment of long-term variability of crop yield under a wide range of agronomic and environmental conditions.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA06103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58785333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anaerobic digestion and electrochemical oxidation were investigated for their potential to recycle carbon and degrade nitrogen from dairy manure; the energy balance of this combination of treatments was also evaluated. Anaerobic digestion is a sustainable technology that allows recovery of biomass energy and treatment of animal wastes for carbon recycling. Since the anaerobic digestion process performs denitrification poorly, almost all nitrogenous substances are discharged in digested effluent as ammonia. The ammonium nitrogen in anaerobically digested effluent is degraded by electrochemical oxidation with an unsacrificial anode. The electrochemical oxidation requires inputs of electricity. We evaluated the feasibility of using electricity generated by a full-scale biogas plant, producing biogas from dairy manure, for the electrochemical oxidation of ammonium nitrogen in anaerobically digested effluent. Data on the amount of electricity generated by such a plant were compared with data on the electricity requirements of the electrochemical oxidation process to determine the energy balance of the two processes. The results indicated that electricity generated from a biogas plant was able to supply 24 to 33% of the electricity required for the electrochemical oxidation.
{"title":"Nitrogen and energy balances of a combined anaerobic digestion and electrochemical oxidation process for dairy manure management","authors":"I. Ihara, K. Toyoda, Tsuneo Watanabe, K. Umetsu","doi":"10.1071/EA07254","DOIUrl":"https://doi.org/10.1071/EA07254","url":null,"abstract":"Anaerobic digestion and electrochemical oxidation were investigated for their potential to recycle carbon and degrade nitrogen from dairy manure; the energy balance of this combination of treatments was also evaluated. Anaerobic digestion is a sustainable technology that allows recovery of biomass energy and treatment of animal wastes for carbon recycling. Since the anaerobic digestion process performs denitrification poorly, almost all nitrogenous substances are discharged in digested effluent as ammonia. The ammonium nitrogen in anaerobically digested effluent is degraded by electrochemical oxidation with an unsacrificial anode. The electrochemical oxidation requires inputs of electricity. We evaluated the feasibility of using electricity generated by a full-scale biogas plant, producing biogas from dairy manure, for the electrochemical oxidation of ammonium nitrogen in anaerobically digested effluent. Data on the amount of electricity generated by such a plant were compared with data on the electricity requirements of the electrochemical oxidation process to determine the energy balance of the two processes. The results indicated that electricity generated from a biogas plant was able to supply 24 to 33% of the electricity required for the electrochemical oxidation.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07254","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58795367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. T. Denmead, Deli Chen, D. Griffith, Z. Loh, M. Bai, T. Naylor
Emissions of indirect greenhouse gases, notably the nitrogen gases ammonia (NH3) and the odd oxides of nitrogen (NOx), play important roles in the greenhouse story. Feedlots are intense, but poorly quantified, sources of atmospheric NH3 and although production of NOx is to be expected in feedlots, rates of NOx emission are virtually unknown. In the atmosphere, these gases are involved in several transformations, but eventually return to the earth in gaseous or liquid form and can then undergo further transformations involving the formation and emission of the direct greenhouse gas nitrous oxide (N2O). The IPCC Phase II guidelines estimate that indirect N2O emissions due to atmospheric deposition of N compounds formed from NH3 and NOx could be ~14% of the direct emissions from agricultural soils or from animal production systems. IPCC recommends that these indirect emissions be accounted for in making inventory estimates of N2O emission. This paper is a preliminary report of emissions of NH3 and NOx from two Australian feedlots determined with micrometeorological techniques. Emissions of nitrogen gases from both feedlots were dominated by emissions of NH3. The average NH3 emission rate over both feedlots in winter was 46 g N/animal.day, while that of NOx was less than 1% of that rate at 0.36 g N/animal.day. It was apparent that NH3 release was governed by the wetness of the surface. Rates of emission from the feedlot with the wetter surface were almost three times those from the other. The IPCC default emission factor for the combined emission of NH3 and NOx from livestock is 0.2 kg N/kg N excreted, but in our work, the emission factor was 0.59 kg N/kg N excreted. Potential emissions of N2O due to NH3 and NOx deposition were estimated to be of the same magnitude as the direct N2O emissions, the sum of direct and potential indirect amounting to ~3 g N2O-N/animal.day. If applied nationally, this would represent a contribution of N2O from Australian feedlots of 533Gg CO2-e or 2.2% of all Australian N2O emissions.
间接温室气体的排放，特别是氮气体氨(NH3)和氮氧化物(NOx)，在温室效应中起着重要作用。饲养场是大气NH3的密集来源，但缺乏量化，尽管预计饲养场会产生氮氧化物，但氮氧化物排放率实际上是未知的。在大气中，这些气体参与了几次转化，但最终以气态或液态形式返回地球，然后可以进行进一步的转化，包括形成和排放直接温室气体一氧化二氮(N2O)。IPCC第二阶段指南估计，由于NH3和NOx形成的N化合物在大气中的沉积而间接排放的N2O可能占农业土壤或动物生产系统直接排放的14%。政府间气候变化专门委员会建议，在编制一氧化二氮排放清单估算时，应考虑到这些间接排放。本文是用微气象技术测定澳大利亚两个饲养场NH3和NOx排放量的初步报告。两个饲养场的氮排放以NH3排放为主。两个饲料场冬季NH3平均排放量为46 g N/头。而在0.36 g N/动物d时，氮氧化物的生长量不足该比率的1%。很明显，NH3的释放受地表湿度的支配。表面较湿的饲养场的排放率几乎是另一个饲养场的三倍。IPCC对畜禽NH3和NOx联合排放的默认排放因子为0.2 kg N/kg N排泄，但在我们的工作中，排放因子为0.59 kg N/kg N排泄。NH3和NOx沉积导致的N2O潜在排放估计与直接N2O排放量相同，直接和潜在间接排放的总和约为~3 g N2O- n /动物日。如果在全国范围内应用，这将代表澳大利亚饲养场对N2O的贡献为533g CO2-e，占澳大利亚N2O总排放量的2.2%。
{"title":"Emissions of the indirect greenhouse gases NH3 and NOx from Australian beef cattle feedlots","authors":"O. T. Denmead, Deli Chen, D. Griffith, Z. Loh, M. Bai, T. Naylor","doi":"10.1071/EA07276","DOIUrl":"https://doi.org/10.1071/EA07276","url":null,"abstract":"Emissions of indirect greenhouse gases, notably the nitrogen gases ammonia (NH3) and the odd oxides of nitrogen (NOx), play important roles in the greenhouse story. Feedlots are intense, but poorly quantified, sources of atmospheric NH3 and although production of NOx is to be expected in feedlots, rates of NOx emission are virtually unknown. In the atmosphere, these gases are involved in several transformations, but eventually return to the earth in gaseous or liquid form and can then undergo further transformations involving the formation and emission of the direct greenhouse gas nitrous oxide (N2O). The IPCC Phase II guidelines estimate that indirect N2O emissions due to atmospheric deposition of N compounds formed from NH3 and NOx could be ~14% of the direct emissions from agricultural soils or from animal production systems. IPCC recommends that these indirect emissions be accounted for in making inventory estimates of N2O emission. This paper is a preliminary report of emissions of NH3 and NOx from two Australian feedlots determined with micrometeorological techniques. Emissions of nitrogen gases from both feedlots were dominated by emissions of NH3. The average NH3 emission rate over both feedlots in winter was 46 g N/animal.day, while that of NOx was less than 1% of that rate at 0.36 g N/animal.day. It was apparent that NH3 release was governed by the wetness of the surface. Rates of emission from the feedlot with the wetter surface were almost three times those from the other. The IPCC default emission factor for the combined emission of NH3 and NOx from livestock is 0.2 kg N/kg N excreted, but in our work, the emission factor was 0.59 kg N/kg N excreted. Potential emissions of N2O due to NH3 and NOx deposition were estimated to be of the same magnitude as the direct N2O emissions, the sum of direct and potential indirect amounting to ~3 g N2O-N/animal.day. If applied nationally, this would represent a contribution of N2O from Australian feedlots of 533Gg CO2-e or 2.2% of all Australian N2O emissions.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07276","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58796312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of defaunation on feed digestion and on methane production of ewes was determined 10 and 25 weeks after defaunation. When fed a lucerne diet (800 g/day), the absence of protozoa did not change the apparent digestibility of dry matter, excretion of macro-minerals, or methane production 10 or 25 weeks post-treatment. Defaunation did, however, increase microbial protein flow by 22% (estimated from allantoin excretion) and the molar proportions of acetate and butyrate in the rumen, while decreasing excretion of copper and manganese. The fermentation data contrasts with previous studies that found defaunation reduced methanogenesis and rumen acetate proportions, but supports the hypothesis that a reduction in rumen acetate percentage is required to achieve reduced methanogenesis through defaunation.
{"title":"Persistence of defaunation effects on digestion and methane production in ewes","authors":"S. H. Bird, R. Hegarty, R. Woodgate","doi":"10.1071/EA07298","DOIUrl":"https://doi.org/10.1071/EA07298","url":null,"abstract":"The effect of defaunation on feed digestion and on methane production of ewes was determined 10 and 25 weeks after defaunation. When fed a lucerne diet (800 g/day), the absence of protozoa did not change the apparent digestibility of dry matter, excretion of macro-minerals, or methane production 10 or 25 weeks post-treatment. Defaunation did, however, increase microbial protein flow by 22% (estimated from allantoin excretion) and the molar proportions of acetate and butyrate in the rumen, while decreasing excretion of copper and manganese. The fermentation data contrasts with previous studies that found defaunation reduced methanogenesis and rumen acetate proportions, but supports the hypothesis that a reduction in rumen acetate percentage is required to achieve reduced methanogenesis through defaunation.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07298","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58796997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jung-Jeng Su, Yen-Jung Chen, Yuanyuan Chang, Szu-Ching Tang
This study aimed to improve the utilisation of biogas in pig farms, the promotion of biogas use and the reduction of greenhouse gas (i.e. methane, carbon dioxide, and nitrous oxide) emissions to the atmosphere. Sulfur oxidisers can convert sulfide (S2–) to sulfur (S0) and even sulfate (SO42–). Strains of CYAS-1, CYAS-2, SW-1, SW-2, and SW-3 were isolated from environmental samples and proven to have capabilities of sulfide oxidation by growing them in 150 mL liquid media with 1.5 g sulfur powder. An increase in sulfate concentration was used to select sulfide oxidisers. Strains CYAS-1 and CYAS-2, which both had significant sulfide oxidation capability, were isolated from the sludge of piggery wastewater treatment facilities. Moreover, strains SW-1, SW-2, and SW-3 were isolated from a pilot-scale biogas bio-filter (BBF) reactor. The experimental results showed that strain CYAS-1 (identified as Acinetobacter spp.), grown in diluted trypticase soy broth (TSB) with sulfur powder, increased the concentrations of SO42– from 17.2 ± 0.5 to 23.8 ± 1.0 mg/L (38.4% increase). Strain CYAS-2 (identified as Corynebacterium spp.), grown in diluted TSB with sulfur powder, increased concentrations of SO42– from 17.7 ± 0.1 to 25.9 ± 0.9 mg/L (47.0% increase). Concentrations of SO42– were increased 40.5, 33.6, and 29.7% in the presence of strains SW-1 (Candida kruse/inconspicua; 96.2% identity), SW-2 (Candida parapsilosis; 93.2% identity), and SW-3 (Trichosporon mucoides; 95.7% identity), respectively.
{"title":"Isolation of sulfide oxidisers for desulfurising biogas produced from anaerobic piggery wastewater treatment in Taiwan.","authors":"Jung-Jeng Su, Yen-Jung Chen, Yuanyuan Chang, Szu-Ching Tang","doi":"10.1071/EA07248","DOIUrl":"https://doi.org/10.1071/EA07248","url":null,"abstract":"This study aimed to improve the utilisation of biogas in pig farms, the promotion of biogas use and the reduction of greenhouse gas (i.e. methane, carbon dioxide, and nitrous oxide) emissions to the atmosphere. Sulfur oxidisers can convert sulfide (S2–) to sulfur (S0) and even sulfate (SO42–). Strains of CYAS-1, CYAS-2, SW-1, SW-2, and SW-3 were isolated from environmental samples and proven to have capabilities of sulfide oxidation by growing them in 150 mL liquid media with 1.5 g sulfur powder. An increase in sulfate concentration was used to select sulfide oxidisers. Strains CYAS-1 and CYAS-2, which both had significant sulfide oxidation capability, were isolated from the sludge of piggery wastewater treatment facilities. Moreover, strains SW-1, SW-2, and SW-3 were isolated from a pilot-scale biogas bio-filter (BBF) reactor. The experimental results showed that strain CYAS-1 (identified as Acinetobacter spp.), grown in diluted trypticase soy broth (TSB) with sulfur powder, increased the concentrations of SO42– from 17.2 ± 0.5 to 23.8 ± 1.0 mg/L (38.4% increase). Strain CYAS-2 (identified as Corynebacterium spp.), grown in diluted TSB with sulfur powder, increased concentrations of SO42– from 17.7 ± 0.1 to 25.9 ± 0.9 mg/L (47.0% increase). Concentrations of SO42– were increased 40.5, 33.6, and 29.7% in the presence of strains SW-1 (Candida kruse/inconspicua; 96.2% identity), SW-2 (Candida parapsilosis; 93.2% identity), and SW-3 (Trichosporon mucoides; 95.7% identity), respectively.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07248","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58795153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Ugalde, J. V. Vliet, Anthony McGregor, B. Slattery
The interface between policy and science provides rich opportunity to frame both the policy and science agendas for the reduction of emissions of greenhouse gases from agriculture. The current Greenhouse Gas in Animal Agriculture Conference (2007) provides a valuable forum for the development and integration of the two. Compared with the level of investments worldwide into technologies to reduce emissions from energy generation and transport, investments into managing and reducing emissions from the agriculture and land sectors have lagged, sadly, far behind. Nonetheless, there still remains strong opportunity to reduce substantially the net emissions from the land-based sector while also improving productivity and financial return (both short and long term). Over the past few decades, it has probably been the science agenda that provided the main impetus for understanding the management of processes that give rise to greenhouse gas emissions from agriculture and for improving management options to reduce these emissions. However, recently a range of new policy approaches (both in Australia and elsewhere) have come into play, and these approaches are now demanding a greater suite and possibly a different set of information from science – and over a short timeframe – to provide the technical means for change to be implemented. The challenge for science is to understand the new demands from the policy agendas, and to resolve how the science community can best deliver what is required. In this way science will be delivering additional benefits to agricultural industries and rural communities as activities in the land-based sector align with national interest and opportunities.
{"title":"Policy options to manage greenhouse gas emissions from the livestock sector: an Australian perspective","authors":"D. Ugalde, J. V. Vliet, Anthony McGregor, B. Slattery","doi":"10.1071/EAV48N2POLICY","DOIUrl":"https://doi.org/10.1071/EAV48N2POLICY","url":null,"abstract":"The interface between policy and science provides rich opportunity to frame both the policy and science agendas for the reduction of emissions of greenhouse gases from agriculture. The current Greenhouse Gas in Animal Agriculture Conference (2007) provides a valuable forum for the development and integration of the two. Compared with the level of investments worldwide into technologies to reduce emissions from energy generation and transport, investments into managing and reducing emissions from the agriculture and land sectors have lagged, sadly, far behind. Nonetheless, there still remains strong opportunity to reduce substantially the net emissions from the land-based sector while also improving productivity and financial return (both short and long term). Over the past few decades, it has probably been the science agenda that provided the main impetus for understanding the management of processes that give rise to greenhouse gas emissions from agriculture and for improving management options to reduce these emissions. However, recently a range of new policy approaches (both in Australia and elsewhere) have come into play, and these approaches are now demanding a greater suite and possibly a different set of information from science – and over a short timeframe – to provide the technical means for change to be implemented. The challenge for science is to understand the new demands from the policy agendas, and to resolve how the science community can best deliver what is required. In this way science will be delivering additional benefits to agricultural industries and rural communities as activities in the land-based sector align with national interest and opportunities.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59080118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
McAllister, T. A., Newbold, C. J. (2008). Redirecting rumen fermentation to reduce methanogenesis. Australian Journal of Experimental Agriculture, 48, (1-2), 7-13.
{"title":"Redirecting rumen fermentation to reduce methanogenesis","authors":"T. McAllister, C. Newbold","doi":"10.1071/EA07218","DOIUrl":"https://doi.org/10.1071/EA07218","url":null,"abstract":"McAllister, T. A., Newbold, C. J. (2008). Redirecting rumen fermentation to reduce methanogenesis. Australian Journal of Experimental Agriculture, 48, (1-2), 7-13.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07218","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58793940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, data from an experiment with 10 purebred Holstein, Simmental and Jersey cows each were analysed to test the assumption that there are genetically low methane-producing animals. Methane emission of cows offered forage ad libitum and some concentrate was measured for 3 days in open-circuit respiration chambers in weeks 8, 15, 23, 33 and 41 of lactation. Individual cow data were analysed in five different ways: (i) plotting the trend of methane per unit of dry matter intake (DMI) and milk yield over time; relating measured methane production to estimates derived from equations based on either; (ii) DMI or (iii) nutrient intake; (iv) relating residual feed intake (RFI) to methane emission; and (v) analysis of variance of cow × measurement interactions. The Holstein, Simmental and Jersey cows emitted on average 25, 25 and 26 g methane/kg DMI, respectively. There was no indication of individual cows with persistently low or high methane yield per kg DMI and per kg milk. Measured methane emissions differed from estimated values without a clear pattern, and the relationship between RFI and methane emission of the cows was weak. Finally, analysis of variance failed to show distinct patterns of methane per unit of DMI and milk for individual animals. The apparent lack of persistence of individual animal differences in methane yields suggests that genetic determination of this trait is of minor importance in dairy cows.
在目前的研究中，对10头纯种荷斯坦奶牛、西门塔尔奶牛和泽西奶牛的实验数据进行了分析，以验证存在基因上低甲烷排放动物的假设。于泌乳期第8、15、23、33和41周，在开式呼吸室中连续3 d测量奶牛自由饲喂饲料和部分精料的甲烷排放量。对奶牛个体数据进行了五种不同的分析:(i)绘制单位干物质摄入量(DMI)和产奶量随时间的变化趋势;将测量的甲烷产量与基于两者之一的方程得出的估计值联系起来;(ii) DMI或(iii)营养摄入量;(iv)将剩余采食量与甲烷排放联系起来;(v)奶牛与测量相互作用的方差分析。荷斯坦奶牛、西门塔尔奶牛和泽西奶牛的平均甲烷排放量分别为25、25和26 g /kg DMI。没有迹象表明个别奶牛的每公斤DMI和每公斤牛奶的甲烷产量持续低或高。实测甲烷排放量与估计值差异不明显，RFI与奶牛甲烷排放量的关系较弱。最后，方差分析未能显示出个体动物单位DMI和牛奶中甲烷含量的不同模式。甲烷产量的个体差异明显缺乏持久性，这表明这一性状的遗传决定对奶牛的重要性不大。
{"title":"Absence of persistent methane emission differences in three breeds of dairy cows","authors":"A. Münger, M. Kreuzer","doi":"10.1071/EA07219","DOIUrl":"https://doi.org/10.1071/EA07219","url":null,"abstract":"In the present study, data from an experiment with 10 purebred Holstein, Simmental and Jersey cows each were analysed to test the assumption that there are genetically low methane-producing animals. Methane emission of cows offered forage ad libitum and some concentrate was measured for 3 days in open-circuit respiration chambers in weeks 8, 15, 23, 33 and 41 of lactation. Individual cow data were analysed in five different ways: (i) plotting the trend of methane per unit of dry matter intake (DMI) and milk yield over time; relating measured methane production to estimates derived from equations based on either; (ii) DMI or (iii) nutrient intake; (iv) relating residual feed intake (RFI) to methane emission; and (v) analysis of variance of cow × measurement interactions. The Holstein, Simmental and Jersey cows emitted on average 25, 25 and 26 g methane/kg DMI, respectively. There was no indication of individual cows with persistently low or high methane yield per kg DMI and per kg milk. Measured methane emissions differed from estimated values without a clear pattern, and the relationship between RFI and methane emission of the cows was weak. Finally, analysis of variance failed to show distinct patterns of methane per unit of DMI and milk for individual animals. The apparent lack of persistence of individual animal differences in methane yields suggests that genetic determination of this trait is of minor importance in dairy cows.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07219","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58794017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emissions of methane (CH4), carbon dioxide (CO2), nitrous oxide (N2O) and ammonia (NH3) during the storage of rough pig slurry and the fractions (solid and liquid) obtained by mechanical separation were investigated in a laboratory-scale study. Manures were stored for a period of 30 days in open vessels (1500 cm3 capacity) within a climate-controlled room which was kept at 25 ± 0.2°C. Gaseous emissions were determined with the dynamic chamber method by infrared photoacoustic detection. The main GHG emission from the liquid manures was CH4. CH4 losses from both liquid and solid fractions together were 3% higher than from the rough slurry. CO2 losses from both liquid and solid fractions together increased by 10% compared with rough pig slurry. Appreciable N2O fluxes were only measured from the solid fraction. Combining the losses during the storage of both liquid and solid fraction, they resulted in reduced NH3 emissions compared with the storage of the rough pig slurry. Evidence from the present study suggests that mechanical separation of pig slurry has the potential to increase up to 25% the emission of CO2-equivalents to the atmosphere during the storage of the separated fractions if compared with the rough slurry.
{"title":"GHG emissions during the storage of rough pig slurry and the fractions obtained by mechanical separation","authors":"E. Dinuccio, P. Balsari, W. Berg","doi":"10.1071/EA07239","DOIUrl":"https://doi.org/10.1071/EA07239","url":null,"abstract":"Emissions of methane (CH4), carbon dioxide (CO2), nitrous oxide (N2O) and ammonia (NH3) during the storage of rough pig slurry and the fractions (solid and liquid) obtained by mechanical separation were investigated in a laboratory-scale study. Manures were stored for a period of 30 days in open vessels (1500 cm3 capacity) within a climate-controlled room which was kept at 25 ± 0.2°C. Gaseous emissions were determined with the dynamic chamber method by infrared photoacoustic detection. The main GHG emission from the liquid manures was CH4. CH4 losses from both liquid and solid fractions together were 3% higher than from the rough slurry. CO2 losses from both liquid and solid fractions together increased by 10% compared with rough pig slurry. Appreciable N2O fluxes were only measured from the solid fraction. Combining the losses during the storage of both liquid and solid fraction, they resulted in reduced NH3 emissions compared with the storage of the rough pig slurry. Evidence from the present study suggests that mechanical separation of pig slurry has the potential to increase up to 25% the emission of CO2-equivalents to the atmosphere during the storage of the separated fractions if compared with the rough slurry.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58794687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Beauchemin, M. Kreuzer, F. O'Mara, T. McAllister
A variety of nutritional management strategies that reduce enteric methane (CH4) production are discussed. Strategies such as increasing the level of grain in the diet, inclusion of lipids and supplementation with ionophores (>24 ppm) are most likely to be implemented by farmers because there is a high probability that they reduce CH4 emissions in addition to improving production efficiency. Improved pasture management, replacing grass silage with maize silage and using legumes hold some promise for CH4 mitigation but as yet their impact is not sufficiently documented. Several new strategies including dietary supplementation with saponins and tannins, selection of yeast cultures and use of fibre-digesting enzymes may mitigate CH4, but these still require extensive research. Most of the studies on reductions in CH4 from ruminants due to diet management are short-term and focussed only on changes in enteric emissions. Future research must examine long-term sustainability of reductions in CH4 production and impacts on the entire farm greenhouse gas budget.
{"title":"Nutritional management for enteric methane abatement: A review","authors":"K. Beauchemin, M. Kreuzer, F. O'Mara, T. McAllister","doi":"10.1071/EA07199","DOIUrl":"https://doi.org/10.1071/EA07199","url":null,"abstract":"A variety of nutritional management strategies that reduce enteric methane (CH4) production are discussed. Strategies such as increasing the level of grain in the diet, inclusion of lipids and supplementation with ionophores (>24 ppm) are most likely to be implemented by farmers because there is a high probability that they reduce CH4 emissions in addition to improving production efficiency. Improved pasture management, replacing grass silage with maize silage and using legumes hold some promise for CH4 mitigation but as yet their impact is not sufficiently documented. Several new strategies including dietary supplementation with saponins and tannins, selection of yeast cultures and use of fibre-digesting enzymes may mitigate CH4, but these still require extensive research. Most of the studies on reductions in CH4 from ruminants due to diet management are short-term and focussed only on changes in enteric emissions. Future research must examine long-term sustainability of reductions in CH4 production and impacts on the entire farm greenhouse gas budget.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07199","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58793441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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