• 한국축산시설환경학회지
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• 제20권4호
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• pp.139-146
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• 2014

This research was conducted to examine the temporal methane ($CH_4$) and nitrous oxide ($N_2O$) emission trends in livestock agriculture from year 1990 to 2011 with Tier 1 national greenhouse gas (GHG) inventory reporting method, which was related to efforts of decreasing GHG emissions and to achievement of voluntary GHG mitigation target. Methane emissions from enteric fermentation were calculated with default $CH_4$ emission factors of IPCC. Methane and $N_2O$ emissions from manure treatment processes were calculated with Tier 1 and mixture of Tier 1 and Tier 2 including $N_2O$ emission factors of manure treatment systems and nitrogen excretion rate of livestock, respectively. According to 2013 National GHG Inventory Monitoring, Reporting, and Verification report, GHG emission fluctuations from enteric fermentation and manure treatment processes were similarto livestock head fluctuation. GHG emissions from enteric fermentation were mainly affected by beef cattle including Hanwoo, while manure treatment processes were affected by various livestock.

• Animal Bioscience
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• 제37권2_spc호
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• pp.323-336
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• 2024

Molecular hydrogen (H₂) and formate (HCOO^-) are metabolic end products of many primary fermenters in the rumen ecosystem. Both play a vital role in fermentation where they are electron sinks for individual microbes in an anaerobic environment that lacks external electron acceptors. If H₂ and/or formate accumulate within the rumen, the ability of primary fermenters to regenerate electron carriers may be inhibited and microbial metabolism and growth disrupted. Consequently, H₂- and/or formate-consuming microbes such as methanogens and possibly homoacetogens play a key role in maintaining the metabolic efficiency of primary fermenters. There is increasing interest in identifying approaches to manipulate the rumen ecosystem for the benefit of the host and the environment. As H₂ and formate are important mediators of interspecies interactions, an understanding of their production and utilization could be a significant starting point for the development of successful interventions aimed at redirecting electron flow and reducing methane emissions. We conclude by discussing in brief ruminant methane mitigation approaches as a model to help understand the fate of H₂ and formate in the rumen ecosystem.

• Asian-Australasian Journal of Animal Sciences
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• 제16권7호
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• pp.1030-1034
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• 2003

Two experiments of four-week duration were conducted to investigate the effect of caecectomy on the intestinal characteristics, body weight gain and gas production in the caeca of White Roman goslings. In experiment I, forty eight 2-wk-old female goslings with similar body weight were randomly divided into four treatments: sham (SHAM), left side caecum removed (LSCR), right side caecum removed (RSCR) and both caeca removed (CAECECTOMY). Smimilarly, experiment II was conducted with twelve 5-wkold male goslings in two treatments: SHAM and CAECECTOMY. Free choice water with ad libitum feed was provided during experiment. At the end of experiment I, goslings were sacrificed and gut length and weight were determined. At 7 and 9 wks of age, birds in experiment II were subjected to respiration calorimetry studies. In both experiments, final body weights were not affected by caecectomy. Results of experiment I indicated that caecectomy did not significantly affect the relative weight (g/100 g BW) of gizzard, small intestine, rectum and colon (p>0.05); however, the relative length of colon and rectum did increase (p<0.05). The remaining caecum did not show compensatory growth in both LSCR and RSCR treatments. In experiment II, results indicated that the average enteric methane production from the caecetomised goslings was significantly lower than that from the bird in SHAM goslings (p<0.05). In comparison with SHAM goslings, calorific loss from entric methane in caecetomised birds was lower (p<0.05). There was no effect of age on methane production. The enteric nitrous oxide production in caeca of goslings was very low with no significantly different between two treatments.

• Asian-Australasian Journal of Animal Sciences
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• 제20권8호
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• pp.1305-1318
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• 2007

On a global scale agriculture and in particular enteric fermentation in ruminants is reported to produce about one fourth (21 to 25%) of the total anthropogenic emissions of methane ($CH_4$). Methane is produced during the anaerobic fermentation of hydrolyzed dietary carbohydrates in the rumen and represents an energy loss to the host besides contributing to emissions of greenhouse gases into the environment. However, there appears to be uncertainty in the $CH_4$ estimation from livestock due to the limited availability of data to document the variability at the farm level and also due to the significant impact of diet on the enteric $CH_4$ production. The methane mitigation strategies require robust prediction of emissions from rumen. There are many methods available which would be suitable for measuring $CH_4$ produced from the various stages of animal production. However, several factors need to be considered in order to select the most appropriate technique like the cost, level of accuracy required and the scale and design of the experiments to be undertaken. Selection of any technique depends on the accuracy as each one has its advantages and disadvantages. Screening of mitigation strategies may be evaluated using individual animal before large-scale trials on groups of animals are carried out. In this review various methods for the estimation of methane production from ruminants as well as for the determination of methane production potential of ruminant feeds are discussed. The advantages and disadvantages of the methods starting from respiration chamber, ventilated hood, facemask, sulphur hexafluoride ($SF_6$) tracer technique, prediction equations and meteorological methods to in vitro methods are detailed.

• Journal of Animal Science and Technology
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• 제60권6호
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• pp.15.1-15.10
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• 2018

Methane emission from the enteric fermentation of ruminant livestock is a main source of greenhouse gas (GHG) emission and a major concern for global warming. Methane emission is also associated with dietary energy lose; hence, reduce feed efficiency. Due to the negative environmental impacts, methane mitigation has come forward in last few decades. To date numerous efforts were made in order to reduce methane emission from ruminants. No table mitigation approaches are rumen manipulation, alteration of rumen fermentation, modification of rumen microbial biodiversity by different means and rarely by animal manipulations. However, a comprehensive exploration for a sustainable methane mitigation approach is still lacking. Dietary modification is directly linked to changes in the rumen fermentation pattern and types of end products. Studies showed that changing fermentation pattern is one of the most effective ways of methane abatement. Desirable dietary changes provide two fold benefits i.e. improve production and reduce GHG emissions. Therefore, the aim of this review is to discuss biology of methane emission from ruminants and its mitigation through dietary manipulation.

• 한국초지조사료학회지
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• 제38권1호
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• pp.39-43
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• 2018

The objective of this study was to determine the effect of various roughage sources on nutrient digestibility and enteric methane ($CH_4$), and carbon dioxide ($CO_2$) production in goats. Four castrated black goats ($48.5{\pm}0.6kg$) were individually housed in environmentally controlled respiration-metabolism chambers. The experiment design was a $4{\times}4$ balanced Latin square design with 4 roughage types and 4 periods. Alfalfa, tall fescue, rice straw, and corn silage was used as representative of legume, grass, straw, and silage, respectively. Dry matter digestibility was higher (p < 0.001) in corn silage than in alfalfa hay. Dry matter digestibility of alfalfa hay was higher than those of tall fescue or rice straw (p < 0.001). Neutral detergent fiber digestibility of tall fescue was lower (p < 0.001) than those of alfalfa, rice straw, or corn silage. Daily enteric $CH_4$ production and the daily enteric $CH_4$ production per kilogram of $BW^{0.75}$, dry matter intake (DMI), organic matter intake (OMI), digested DMI, and digested OMI of rice straw did not differ from those of tall fescue but were higher (p < 0.001) than those of alfalfa or corn silage. Roughage type had no effect on enteric $CO_2$ emission in goats. Straw appeared to generate more enteric $CH_4$ production than legume or silage, but similar to grass.

• 한국유기농업학회지
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• 제22권3호
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• pp.491-502
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• 2014

본 연구는 천연물질에서 유래한 반추위 메탄저감용 친환경 첨가제 개발을 위해 각기 다른 종균을 이용하여 발효한 세신 추출물의 항균활성, 항산화활성 및 in vitro 반추위 발효시험을 체계적으로 실시하였다. 접종된 균주들의 성장효율을 알아보기 위해 실시한 생균수측정 결과 L. curvatus NJ40 균주에서 유의적으로 높은 균주성장을 나타냈다(p<0.05). 항균활성측정 결과는 대조구 대비 L. curvatus NJ40 및 L. plantarum NJ45 균주와 발효된 세신 추출물이 병원균에 대한 항균효과를 나타내는 것으로 조사되었다. In vitro 반추위 발효실험에 세신 및 발효 세신 추출물을 적용한 결과, 휘발성 지방산 생성량 대비 반추위 메탄 저감효과가 나타났다. 특히 반추위 미생물 활력 및 사료이용 효율을 대표할 수 있는 휘발성 지방산 생성효율에 대한 부정적 효과 없이, 오히려 휘발성지방산 생성효율을 향상시키면서 반추위 메탄 저감효과를 가져올 수 있는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권2호
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• pp.295-302
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• 2011

Almost half of New Zealand's greenhouse gas emissions arise from agriculture and enteric methane ($CH_4 $) emissions arising from ruminant animals constitute 30% of total $CO_2$-e emissions. Enteric $CH_4$ emissions have increased by 9% since 1990. Extensive research has been undertaken to develop reliable methods for measuring enteric $CH_4$ emissions. New Zealand studies using the SF6 tracer technique suggest that on average this technique yields similar values to the 'gold' standard of calorimetry, but with a larger variance. National inventory estimates based on results obtained using the $SF_6$ technique will therefore overestimate the uncertainty. Mitigating emissions can be achieved by changing feed type but there are practical and cost barriers to the use of alternative feeds. Forages containing condensed tannins do reduce emissions but are agronomically inferior to the forages currently used. Rumen additives have shown some success in-vitro but results from in-vivo trials with both monensin and fumaric acid have been disappointing. The development of methods for directly manipulating rumen microorganisms are at an early stage and work to develop vaccines that can inhibit methanogenesis has yielded mixed results. The successful identification of sheep with contrasting $CH_4$ yields raises the possibility that, in the long term, a breeding approach to $CH_4$ mitigation is feasible.

• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1238-1243
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• 2018

Objective: Two experiments were conducted to determine the effects of feeding level on nutrient digestibility and enteric methane ($CH_4$) emissions in growing goats and Sika deer. Methods: Three growing male goats (initial body weight [BW] of $22.4{\pm}0.9kg$) and three growing male deer (initial BW of $20.2{\pm}4.8kg$) were each allotted to a respiration-metabolism chamber for an adaptation period of 7 d and a data collection period of 3 d. An experimental diet was offered to each animal at one of three feeding levels (1.5%, 2.0%, and 2.5% of BW) in a $3{\times}3$ Latin square design. The chambers were used for measuring enteric $CH_4$ emission. Results: Nutrient digestibility decreased linearly in goats as feeding level increased, whereas Sika deer digestibility was not affected by feeding level. The enteric production of $CH_4$ expressed as g/kg dry matter intake (DMI), g/kg organic matter intake, and % of gross energy intake decreased linearly with increased feeding level in goats; however, that of Sika deer was not affected by feeding level. Six equations were estimated for predicting the enteric $CH_4$ emission from goats and Sika deer. For goat, equation 1 was found to be of the highest accuracy: $CH_4(g/d)=6.2({\pm}14.1)+10.2({\pm}7.01){\times}DMI(kg/d)+0.0048({\pm}0.0275){\times}dry$ matter digestibility (DMD, g/kg)-0.0070 (${\pm}0.0187$)${\times}$neutral detergent fiber digestibility (NDFD; g/kg). For Sika deer, equation 4 was found to be of the highest accuracy: $CH_4(g/d)=-13.0({\pm}30.8)+29.4({\pm}3.93){\times}DMI(kg/d)+0.046(0.094){\times}DMD(g/kg)-0.0363({\pm}0.0636){\times}NDFD(g/kg)$. Conclusion: Increasing the feeding level increased $CH_4$ production in both goats and Sika deer, and predictive models of enteric $CH_4$ production by goats and Sika deer were estimated.

• Asian-Australasian Journal of Animal Sciences
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• 제31권11호
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• pp.1738-1746
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• 2018

Objective: The aim of the experiment was to assess the effect of increasing amounts of Leucaena leucocephala forage on dry matter intake (DMI), organic matter intake (OMI), enteric methane production, rumen fermentation pattern and protozoa population in cattle fed Pennisetum purpureum and housed in respiration chambers. Methods: Five crossbred heifers (Bos taurus${\times}$Bos indicus) (BW: $295{\pm}6kg$) were fed chopped P. purpureum grass and increasing levels of L. leucocephala (0%, 20%, 40%, 60%, and 80% of dry matter [DM]) in a $5{\times}5$ Latin square design. Results: The voluntary intake and methane production were measured for 23 h per day in respiration chambers; molar proportions of volatile fatty acids (VFAs) were determined at 6 h postprandial period. Molar concentration of VFAs in rumen liquor were similar (p>0.05) between treatments. However, methane production decreased linearly (p<0.005), recording a maximum reduction of up to ~61% with 80% of DM incorporation of L. leucocephala in the ration and no changes (p>0.05) in rumen protozoa population were found. Conclusion: Inclusion of 80% of L. leucocephala in the diet of heifers fed low-quality tropical forages has the capacity to reduce up to 61.3% enteric methane emission without affecting DMI, OMI, and protozoa population in rumen liquor.