• Animal Bioscience
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• v.37 no.2
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• pp.173-183
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• 2024

Objective: This study aimed to evaluate whether the methane (CH₄) to carbon dioxide (CO₂) ratio (CH₄/CO₂) and methane-related traits obtained by the sniffer method can be used as indicators for genetic selection of Holstein cows with lower CH₄ emissions. Methods: The sniffer method was used to simultaneously measure the concentrations of CH₄ and CO₂ during milking in each milking box of the automatic milking system to obtain CH₄/CO₂. Methane-related traits, which included CH₄ emissions, CH₄ per energy-corrected milk, methane conversion factor (MCF), and residual CH₄, were calculated. First, we investigated the impact of the model with and without body weight (BW) on the lactation stage and parity for predicting methane-related traits using a first on-farm dataset (Farm 1; 400 records for 74 Holstein cows). Second, we estimated the genetic parameters for CH₄/CO₂ and methane-related traits using a second on-farm dataset (Farm 2; 520 records for 182 Holstein cows). Third, we compared the repeatability and environmental effects on these traits in both farm datasets. Results: The data from Farm 1 revealed that MCF can be reliably evaluated during the lactation stage and parity, even when BW is excluded from the model. Farm 2 data revealed low heritability and moderate repeatability for CH₄/CO₂ (0.12 and 0.46, respectively) and MCF (0.13 and 0.38, respectively). In addition, the estimated genetic correlation of milk yield with CH₄/CO₂ was low (0.07) and that with MCF was moderate (-0.53). The on-farm data indicated that CH₄/CO₂ and MCF could be evaluated consistently during the lactation stage and parity with moderate repeatability on both farms. Conclusion: This study demonstrated the on-farm applicability of the sniffer method for selecting cows with low CH₄ emissions.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.967-972
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• 2017

Objective: Two experiments were conducted to determine the effects of forage-to-concentrate (F:C) ratio on the nutrient digestibility and enteric methane ($CH_4$) emission in growing goats and Sika deer. Methods: Three male growing goats (body weight $[BW]=19.0{\pm}0.7kg$) and three male growing deer ($BW=19.3{\pm}1.2kg$) were respectively allotted to a $3{\times}3$ Latin square design with an adaptation period of 7 d and a data collection period of 3 d. Respiration-metabolism chambers were used for measuring the enteric $CH_4$ emission. Treatments of low (25:75), moderate (50:50), and high (73:27) F:C ratios were given to both goats and Sika deer. Results: Dry matter (DM) and organic matter (OM) digestibility decreased linearly with increasing F:C ratio in both goats and Sika deer. In both goats and Sika deer, the $CH_4$ emissions expressed as g/d, g/kg $BW^{0.75}$, % of gross energy intake, g/kg DM intake (DMI), and g/kg OM intake (OMI) decreased linearly as the F:C ratio increased, however, the $CH_4$ emissions expressed as g/kg digested DMI and OMI were not affected by the F:C ratio. Eight equations were derived for predicting the enteric $CH_4$ emission from goats and Sika deer. For goat, equation 1 was found to be of the highest accuracy: $CH_4(g/d)=3.36+4.71{\times}DMI(kg/d)-0.0036{\times}neutral$ detergent fiber concentrate (NDFC,g/kg)+$0.01563{\times}dry$ matter digestibility (DMD,g/kg)-$0.0108{\times}neutral$ detergent fiber digestibility (NDFD, g/kg). For Sika deer, equation 5 was found to be of the highest accuracy: $CH_4(g/d)=66.3+27.7{\times}DMI(kg/d)-5.91{\times}NDFC(g/kg)-7.11{\times}DMD(g/kg)+0.0809{\times}NDFD(g/kg)$. Conclusion: Digested nutrient intake could be considered when determining the $CH_4$ generation factor in goats and Sika deer. Finally, the enteric $CH_4$ prediction model for goats and Sika deer were estimated.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.3
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• pp.39-49
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• 2020

Rice paddy cultivation is one of the major sources in methane (CH₄) emission of which accurate assessment would be a prerequisite for agricultural greenhouse gas management. Biomass treatment in paddy fields is an important factor that affects CH₄ emissions and thus needs to be taken into account. The objectives of this study were to apply drone images to investigate organic matter practices and to incorporate into the estimation of CH₄ emissions from paddy fields. Three study areas were selected by one from each of the three different regions of Yeongnam, Honam and Jungbu, which are the most active region in paddy cultivation. The eBee drone was used to take images of the study sites twice a year; Jul mid-season for identifying rice cultivation area; Jan for investigating rice straw management and winter crop cultivation. Based on biomass management practices, different emissions factors were assigned on an individual paddy field and CH₄ emmisions were estimated by multiplying respective areas. The ratios of rice straw application and winter crop cultivation were 1.4% and 37.2% in Hapcheon, 1.3% and 19.8% in Gimje, and 0.0% and 0.5% in Dangjin, respectively. The CH₄ emissions estimates for respective sites were 0.40 ton CH₄/year/ha, 0.34 ton CH₄/year/ha, and 0.29 ton CH₄/year/ha. On average, estimated CH₄ emissions of this study were 28.5% less than the current Tier 2 CH₄ emission estimation method.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.45-59
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• 2023

The global focus on mitigating climate change has traditionally centered on carbon dioxide, but recent attention has shifted towards methane as a crucial factor in climate change adaptation. Natural settings, particularly aquatic environments such as wetlands, reservoirs, and lakes, play a significant role as sources of greenhouse gases. The accumulation of organic contaminants on the lake and reservoir beds can lead to the microbial decomposition of sedimentary material, generating greenhouse gases, notably methane, under anaerobic conditions. The escalation of methane emissions in freshwater is attributed to the growing impact of non-point sources, alterations in water bodies for diverse purposes, and the introduction of structures such as river crossings that disrupt natural flow patterns. Furthermore, the effects of climate change, including rising water temperatures and ensuing hydrological and water quality challenges, contribute to an acceleration in methane emissions into the atmosphere. Methane emissions occur through various pathways, with ebullition fluxes-where methane bubbles are formed and released from bed sediments-recognized as a major mechanism. This study employs Biochemical Methane Potential (BMP) tests to analyze and quantify the factors influencing methane gas emissions. Methane production rates are measured under diverse conditions, including temperature, substrate type (glucose), shear velocity, and sediment properties. Additionally, numerical simulations are conducted to analyze the relationship between fluid shear stress on the sand bed and methane ebullition rates. The findings reveal that biochemical factors significantly influence methane production, whereas shear velocity primarily affects methane ebullition. Sediment properties are identified as influential factors impacting both methane production and ebullition. Overall, this study establishes empirical relationships between bubble dynamics, the Weber number, and methane emissions, presenting a formula to estimate methane ebullition flux. Future research, incorporating specific conditions such as water depth, effective shear stress beneath the sediment's tensile strength, and organic matter, is expected to contribute to the development of biogeochemical and hydro-environmental impact assessment methods suitable for in-situ applications.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.439-446
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• 2014

Many studies on methane ($CH_4$) and nitrous oxide ($N_2O$) emissions from livestock industries have revealed that livestock production directly contributes to greenhouse gas (GHG) emissions through enteric fermentation and manure management, which causes negative impacts on animal environment sustainability. In the present study, three essential values for GHG emission were measured; i.e., i) maximum $CH_4$ producing capacity at mesophilic temperature ($37^{\circ}C$) from anaerobically stored manure in livestock category ($B_{0,KM}$, Korean livestock manure for $B_0$), ii) $EF_{3(s)}$ value representing an emission factor for direct $N_2O$ emissions from manure management system S in the country, kg $N_2O-N$ kg $N^{-1}$, at mesophilic ($37^{\circ}C$) and thermophilic ($55^{\circ}C$) temperatures, and iii) $N_{ex(T)}$ emissions showing annual N excretion for livestock category T, kg N $animal^{-1}$ $yr^{-1}$, from different livestock manure. Static incubation with and without aeration was performed to obtain the $N_2O$ and $CH_4$ emissions from each sample, respectively. Chemical compositions of pre- and post- incubated manure were analyzed. Contents of total solids (% TS) and volatile solid (% VS), and the ratio of carbon to nitrogen (C/N) decrease significantly in all the samples by C-containing biogas generation, whereas moisture content (%) and pH increased after incubation. A big difference of total nitrogen content was not observed in pre- and post-incubation during $CH_4$ and $N_2O$ emissions. $CH_4$ emissions (g $CH_4$ kg VS-1) from all the three manures (sows, layers and Korean cattle) were different and high C/N ratio resulted in high $CH_4$ emission. Similarly, $N_2O$ emission was found to be affected by % VS, pH, and temperature. The $B_{0,KM}$ values for sows, layers, and Korean cattle obtained at $37^{\circ}C$ are 0.0579, 0.0006, and 0.0828 $m^3$ $CH_4$ kg $VS^{-1}$, respectively, which are much less than the default values in IPCC guideline (GL) except the value from Korean cattle. For sows and Korean cattle, $N_{ex(T)}$ values of 7.67 and 28.19 kg N $yr^{-1}$, respectively, are 2.5 fold less than those values in IPCC GL as well. However, $N_{ex(T)}$ value of layers 0.63 kg N $yr^{-1}$ is very similar to the default value of 0.6 kg N $yr^{-1}$ in IPCC GLs for National greenhouse gas inventories for countries such as South Korea/Asia. The $EF_{3(s)}$ value obtained at $37^{\circ}C$ and $55^{\circ}C$ were found to be far less than the default value.

• Journal of Animal Science and Technology
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• v.53 no.2
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• pp.161-169
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• 2011

Methane production during anaerobic fermentation in the rumen represents an energy loss to the host animal and induces emissions of greenhouse gases in the environment. Our study focused on comparison in methane production from growing Korean native steers fed different grain sources. Six Hanwoo steers (BW = $180.6{\pm}3.1$ kg) were fed, on a DM basis (TDN 2.80 kg), 40% timothy and 60% barley concentrate (Barley) or corn concentrate (Corn), respectively, based on the Korean Feeding Standards. Each period lasted 18 days including a 14-day adaptation and a 4-day measuring times. The steers were in the head hood chamber system (one cattle per chamber) during each measuring time to measure heat and methane production per day. Different grain sources did not affect digestibilities of dry matter, crude protein, crude fiber, crude fat, NDF, ADF and nitrogen-free extract. The mean methane concentrations per day were 202.0 and 177.1 ppm for Barley and Corn, respectively. Methane emission averaged 86.8 and 77.7 g/day for Barley and Corn, respectively. Methane emission factor by maintenance energy requirement for the growing steers fed barley based concentrate was higher than the steers fed corn based concentrate (Barley vs. Corn, 31.7 kg $CH_4\;head^{-1}\;yr^{-1}$ vs. 28.4 kg $CH_4\;head^{-1}\;yr^{-1}$). Thus, methane conversion rate was 0.065 (6.5%) and 0.055 (5.5%) for Barley and Corn, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.3
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• pp.275-283
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• 2008

Since mobile source is a major source of VOCs, quantifying emissions from motor vehicles is an important factor to control VOCs in atmosphere. In this study, in order to evaluate tailpipe VOCs emissions from motor vehicles, mass emissions of non-methane volatile organic compounds from 45 vehicles were determined. Measurements were made on a chassis dynamometer using CVS-75 mode and speed specific drive modes. Target VOCs are 53 compounds determined as the volatile ozone precursors. The individual VOCs composition of vehicle emission and emission rates were also determined. In case of gasoline vehicles, VOCs emission from over 80,000 km vehicles were about 46% larger than less 80,000 km vehicles. The difference in benzene and toluene according to driving mileage was 44% and 26% respectively. The composition of VOCs were different by fuel type. The order of VOCs composition was paraffins>aromatics>olefins in gasoline vehicle emissions, paraffins>olefins>aromatics in light duty diesel vehicle emissions. The VOCs emissions were decreased as vehicle speed increasing. These results will be used to calculate total VOCs emissions from automobiles in the future.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.315-321
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• 2017

The present experiment was designed to investigate the effects of extruded linseed supplementation on methane production in Holstein steers. Four Holstein steers fitted with permanent cannulas were assigned to two dietary treatments in a duplicated $2{\times}2$ Latin square design: a control diet consisting of tall fescue straw (65%) and concentrate (35%), and a treatment diet supplemented with 3.8% extruded linseed by replacing a part of ingredients in the concentrate of the control diet. The concentrates of the control and the treatment diet were isoenergetic and isonitrogenous. Extruded linseed supplementation did not affect dry matter intake but significantly (P<0.05) increased the intake of lipid. Rumen pH was significantly (P<0.05) lower for control than for treatment. Although there was no significant difference between treatments, the concentration of total VFA in control was 21% higher than in treatment. The concentrations of acetic acid, propionic acid and butyric acid were not different between treatments. Extruded linseed supplementation significantly (P<0.05) reduced methane output(g/d) and emission factor. Methane conversion rate was lower for treatment than for control but no significant difference was found. The results of the present study showed that extruded linseed supplementation in the diet of Holstein steers could reduce methane output.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.374-380
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• 2014

To estimate greenhouse gas (GHG) emission, the inventory of rice cultivation at the farming without agricultural chemicals was established from farmers in Gunsan, Jeonbuk province in 2011~2012. The objectives of this study were to calculate carbon footprint and analyse the major factor of GHGs. To do this, we carried out a sensitivity analysis using the analyzed main factors of GHGs and estimated the mitigation potential of GHGs. Also we suggested agricultural methods to reduce GHGs that can be appled by farmers at this region. At the farming system without agricultural chemicals, carbon footprint of rice production unit of 1 kg was 2.15 kg $CO_2.-eq.kg^{-1}$. Although the amount of carbon dioxide ($CO_2$) emission was the largest among GHGs, methane ($CH_4$) emission had the highest contribution to carbon footprint on rice production system when it was converted to carbon dioxide equivalent ($CO_2-eq.$) multiplied by the global warming potential (GWP). Main source of $CO_2$ emission in the rice farming system without agricultural chemicals was combustion of fossil fuels used by agricultural machinery. Most of the $CH_4$ was emitted during rice cultivation practice and its major emission factor was flooded paddy field in anaerobic condition. Also, most of the $N_2O$ was emitted from rice cultivation process. Major sources of the $N_2O$ emission was application of fertilizer such as compound fertilizer. As a result of sensitivity analysis in energy consumption, diesel had the highest sensitivity among the energy inputs. With the reduction of diesel consumption by 10%, it was estimated that $CO_2$ potential reduction was about 2.0%. With reducing application rate of compound fertilizer by 10%, the potential reduction was calculated that $CO_2$ and $N_2O$ could be reduced by 0.5% and 0.9%, respectively. At the condition of 10% reduction of silicate and compost, $CO_2$ and $CH_4$ could be reduced by 1.5% and 1.6%, respectively. With 8 days more drainage than the ordinary practice, $CH_4$ emission could be reduced by about 4.5%. Drainage and diesel consumption were the main sources having the largest effect on the GHG reduction at the farming system without agricultural chemicals. Based on the above results, we suggest that no-tillage and midsummer drainage could be a method to decrease GHG emissions from rice production system.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.12
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• pp.1805-1811
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• 2016

The goal of this study was to estimate the emissions of greenhouse gases (GHG), namely methane ($CH_4$), nitrous oxide ($N_2O$), and carbon dioxide ($CO_2$) from poultry and pig production in South Korea over the last 10 years (2005 through 2014). The calculations of GHG emissions were based on Intergovernmental Panel on Climate Change (IPCC) guidelines. Over the study period, the $CH_4$ emission from manure management decreased in layer chickens, nursery to finishing pigs and gestating to lactating sows, but there was a gradual increase in $CH_4$ emission from broiler chickens and male breeding pigs. Both sows and nursery to finishing pigs were associated with greater emissions from enteric fermentation than the boars, especially in 2009. Layer chickens produced lower direct and indirect $N_2O$ emissions from 2009 to 2014, whereas the average direct and indirect $N_2O$ emissions from manure management for broiler chickens were 12.48 and $4.93Gg\;CO_2-eq/yr$, respectively. Annual direct and indirect $N_2O$ emissions for broiler chickens tended to decrease in 2014. Average $CO_2$ emission from direct on-farm energy uses for broiler and layer chickens were 46.62 and $136.56Gg\;CO_2-eq/yr$, respectively. For pig sectors, the $N_2O$ emission from direct and indirect sources gradually increased, but they decreased for breeding pigs. Carbon dioxide emission from direct on-farm energy uses reached a maximum of $53.93Gg\;CO_2-eq/yr$ in 2009, but this total gradually declined in 2010 and 2011. For boars, the greatest $CO_2$ emission occurred in 2012 and was $9.44Gg\;CO_2-eq/yr$. Indirect $N_2O$ emission was the largest component of GHG emissions in broilers. In layer chickens, the largest contributing factor to GHG emissions was $CO_2$ from direct on-farm energy uses. For pig production, the largest component of GHG emissions was $CH_4$ from manure management, followed by $CO_2$ emission from direct on-farm energy use and $CH_4$ enteric fermentation emission, which accounted for 8.47, 2.85, and $2.82Gg-CO_2/yr$, respectively. The greatest GHG emission intensity occurred in female breeding sows relative to boars. Overall, it is an important issue for the poultry and pig industry of South Korea to reduce GHG emissions with the effective approaches for the sustainability of agricultural practices.