• Journal of Animal Science and Technology
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• v.63 no.1
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• pp.16-24
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• 2021

The suppressive effect of monensin as an ionophore-feed additive on enteric methane (CH4) emission and renewable methanogenesis were evaluated. To clarify the suppressive effect of monensin a respiratory trial with head cage was performed using Holstein-Friesian steers. Steers were offered high concentrate diets (80% concentrate and 20% hay) ad libitum with or without monensin, galacto-oligosaccharides (GOS) or L-cysteine. Steers that received monensin containing diet had significantly (p < 0.01) lower enteric CH4 emissions as well as those that received GOS containing diet (p < 0.05) compared to steers fed control diets. Thermophilic digesters at 55℃ that received manure from steers fed on monensin diets had a delay in the initial CH4 production. Monensin is a strong inhibitor of enteric methanogenesis, but has a negative impact on biogas energy production at short retention times. Effects of the activity of coprophagous insects on CH4 and nitrous oxide (N2O) emissions from cattle dung pats were assessed in anaerobic in vitro continuous gas quantification system modified to aerobic quantification device. The CH4 emission from dungs with adults of Caccobius jessoensis Harold (dung beetle) and the larvae of the fly Neomyia cornicina (Fabricius) were compared with that from control dung without insect. The cumulative CH4 emission rate from dung with dung insects decreased at 42.2% in dung beetles and 77.8% in fly larvae compared to that from control dung without insects. However, the cumulative N2O emission rate increased 23.4% in dung beetles even though it reduced 88.6% in fly larvae compared to dung without coprophagous insects. It was suggested that the antibacterial efficacy of ionophores supplemented as a growth promoter still continued even in the digested slurry, consequently, possible environmental contamination with the antibiotics might be active to put the negative impact to land ecosystem involved in greenhouse gas mitigation when the digested slurry was applied to the fields as liquid manure.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1577-1583
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• 2014

Encapsulation is a method used to protect material from certain undesirable environments, for controlled release at a more favorable time and place. Animal productivity would be enhanced if feed additives are delivered to be utilized at their site of action, bypassing the rumen where they are likely to be degraded by microbial action. A novel method of encapsulation with sesame gum was used to coat nitrate, a known enteric methane mitigating agent, and tested for the effect on methane reduction and other in vitro fermentation parameters using rumen fluid from cannulated Hanwoo steers. Orchard grass was used as basal diet for fermentation. The treatments were matrix (1.1 g sesame gum+0.4 g sesame oil cake) only, encapsulated nitrate (matrix+nitrate [21 mM]), free nitrate (21 mM), and a control that contained no additive. Analyses of fermentation parameters were done at 0, 3, 6, 9, 12, 24, and 48 h time periods. In comparison to control, both free and encapsulated nitrate produced significantly reduced (p<0.01) methane (76% less) and also the total volatile fatty acids were reduced. A significantly higher (p<0.01) concentration of ammonia nitrogen was obtained with the encapsulated nitrate treatment (44%) compared to the free form (28%) and matrix only (20%) (p = 0.014). This might suggest slow release of encapsulated nitrate so that it is fully reduced to ammonia. Thus, this pioneering study found a significant reduction in methane production following the use of sesame gum encapsulated nitrate that shows the potential of a controlled release system in enhancing sustainability of ruminant production while reducing/eliminating the risk of nitrite toxicity.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.12
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• pp.1768-1774
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• 2012

This study was conducted to evaluate methane ($CH_4$) and nitrous oxide ($N_2O$) emissions from livestock agriculture in 16 local administrative districts of Korea from 1990 to 2030. National Inventory Report used 3 yr averaged livestock population but this study used 1 yr livestock population to find yearly emission fluctuations. Extrapolation of the livestock population from 1990 to 2009 was used to forecast future livestock population from 2010 to 2030. Past (yr 1990 to 2009) and forecasted (yr 2010 to 2030) averaged enteric $CH_4$ emissions and $CH_4$ and $N_2O$ emissions from manure treatment were estimated. In the section of enteric fermentation, forecasted average $CH_4$ emissions from 16 local administrative districts were estimated to increase by 4%-114% compared to that of the past except for Daejeon (-63%), Seoul (-36%) and Gyeonggi (-7%). As for manure treatment, forecasted average $CH_4$ emissions from the 16 local administrative districts were estimated to increase by 3%-124% compared to past average except for Daejeon (-77%), Busan (-60%), Gwangju (-48%) and Seoul (-8%). For manure treatment, forecasted average $N_2O$ emissions from the 16 local administrative districts were estimated to increase by 10%-153% compared to past average $CH_4$ emissions except for Daejeon (-60%), Seoul (-4.0%), and Gwangju (-0.2%). With the carbon dioxide equivalent emissions ($CO_2$-Eq), forecasted average $CO_2$-Eq from the 16 local administrative districts were estimated to increase by 31%-120% compared to past average $CH_4$ emissions except Daejeon (-65%), Seoul (-24%), Busan (-18%), Gwangju (-8%) and Gyeonggi (-1%). The decreased $CO_2$-Eq from 5 local administrative districts was only 34 kt, which was insignificantly small compared to increase of 2,809 kt from other 11 local administrative districts. Annual growth rates of enteric $CH_4$ emissions, $CH_4$ and $N_2O$ emissions from manure management in Korea from 1990 to 2009 were 1.7%, 2.6%, and 3.2%, respectively. The annual growth rate of total $CO_2$-Eq was 2.2%. Efforts by the local administrative offices to improve the accuracy of activity data are essential to improve GHG inventories. Direct measurements of GHG emissions from enteric fermentation and manure treatment systems will further enhance the accuracy of the GHG data.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.801-813
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• 2014

A study was conducted to improve the biological activity of two medicinal plants, Eucommia ulmoides Oliv. and Glycyrrhiza uralensis, by fermentation. The biological activity was assessed by determining antibacterial, antioxidant and antimethanogenic properties. Fermentation was achieved by adding the plant materials in MRS broth at 10% (w/v) and different starter cultures at 1% (v/v). Condition for fermentation were incubation temperature of $30^{\circ}C$ and agitation at 150 rpm for 48 h. Six starter cultures, Weissella confusa NJ28 (Genbank accession number KJ914897), Weissella cibaria NJ33 (Genbank accession number KJ914898), Lactobacillus curvatus NJ40 (Genbank accession number KJ914899), Lactobacillus brevis NJ42 (Genbank accession number KJ914900), Lactobacillus plantarum NJ45 (Genbank accession number KJ914901) and Lactobacillus sakei NJ48 (Genbank accession number KJ914902) were used. Antibacterial activity was observed in L. curvatus NJ40 and L. plantarum NJ45 only as opposed to other treatments, including the non-fermented groups, which showed no antibacterial activity. Both plants showed antioxidant activity, although E. ulmoides Oliv. had lower activity than G. uralensis. However, fermentation by all strains significantly improved (p<0.05), antioxidant activity in both plants compared to non-fermented treatment. Six treatments were based on antibacterial activity results, selected for in vitro rumen fermentation; 1) non-fermented E. ulmoides, 2) fermented E. ulmoides NJ40, 3) fermented E. ulmoides NJ45, 4) non-fermented G. uralensis, 5) fermented G. uralensis NJ40, 6) fermented G. uralensis NJ45. A negative control was also added, making a total of 7 treatments for the in vitro experiment. Medicinal plant-based treatments significantly improved (p<0.05) total volatile fatty acid (VFA) concentration. Significant methane reduction per mol of VFA were observed in G. uralensis (p<0.05). Based on the present study, fermentation improves the biological activity of E. ulmoides Oliv. and G. uralensis. Fermented G. uralensis could also be applied as an enteric methane mitigating agent in ruminant animals.

• Korean Journal of Agricultural Science
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• v.51 no.3
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• pp.283-294
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• 2024

The objective of this study was to investigate the effect of supplementing concentrates in a forage-based diet on methane emissions of pregnant Hanwoo heifers. Twenty-one pregnant Hanwoo heifers (481 ± 42.4 kg) were divided into two groups: 1) a group receiving forage only (control, CON) and 2) the other group receiving forage with 4 kg of a concentrate mix (treatment, TRT). Methane (CH₄) concentration was measured using a laser methane detector, following an 18-d adaptation period, according to previously established protocols. Feed intake was recorded throughout the experimental period. Ruminal fluid was collected and analyzed for pH, ammonia-nitrogen (NH₃-N), and volatile fatty acid (VFA). The TRT exhibited higher dry matter and neutral detergent fiber intake than CON (p < 0.05) with elevated NH₃-N (p < 0.001) and total VFA concentrations (p = 0.013). The proportions of butyrate, valerate, and iso-valerate were higher in TRT than CON (p < 0.05). Notably, CH₄ concentrations per kg dry matter intake was lower in the TRT group, both from respiration and eructation (p < 0.05). In conclusion, supplementing concentrates in a low-quality forage-based diet for pregnant Hanwoo heifers fulfills nutrient requirements and reduces CH₄ emissions, suggesting a potential strategy to reduce environmental impact of Hanwoo production.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1389-1394
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• 2012

Sheanut cake (SNC), expeller (SNE) and solvent extractions (SNSE) samples were evaluated to determine their suitability in animal feeding. The CP content was highest in SNSE (16.2%) followed by SNE (14.7%) and SNC (11.6%). However, metabolizable energy (ME, MJ/kg) was maximum in SNC (8.2) followed by SNE (7.9) and SNSE (7.0). The tannin phenol content was about 7.0 per cent and mostly in the form of hydrolyzable tannin (HT), whereas condensed tannin (CT) was less than one per cent. The in vitro gas production profiles indicated similar y max (maximum potential of gas production) among the 3 by-products. However, the rate of degradation (k) was maximum in SNC followed by SNE and SNSE. The $t^{1/2}$ (time taken for reaching half asymptote) was lowest in SNC (14.4 h) followed by SNE (18.7 h) and SNSE (21.9 h). The increment in the in vitro gas volume (ml/200 mg DM) with PEG (polyethylene glycol)-6000 (as a tannin binder) addition was 12.0 in SNC, 9.6 in SNE and 11.0 in SNSE, respectively. The highest ratio of $CH_4$ (ml) reduction per ml of the total gas, an indicator of the potential of tannin, was recorded in SNE (0.482) followed by SNC (0.301) and SNSE (0.261). There was significant (p<0.05) reduction in entodinia population and total protozoa population. Differential protozoa counts revealed that Entodinia populations increased to a greater extent than Holotricha when PEG was added. This is the first report on the antimethanogenic property of sheanut byproducts. It could be concluded that all the three forms of SN byproducts are medium source of protein and energy for ruminants. There is a great potential for SN by-products to be incorporated in ruminant feeding not only as a source of energy and protein, but also to protect the protein from rumen degradation and suppress enteric methanogenesis.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.2
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• pp.119-127
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• 2021

The objective of this study was to evaluate effects of feeding methods on in vitro ruminal fermentation, total gas and methane production in Hanwoo steers. Six Hanwoo steers fitted with rumen cannula (430 ± 21 kg of body weight) were randomly assigned to one of three feeding systems: 1) feeding forage 1 hour after concentrate, 2) feeding concentrate 1 hour after forage, 3) feeding mixed ration. Rumen fluid sampled from each animals was incubated 24 hours with maize or timothy substrates in in vitro. Ruminal pH was increased in feeding method 2 or maize substrate than that of other methods or timothy substrate (P < 0.001). The production of total volatile fatty acid, acetate, propionate, butyrate, and valerate were increased when steers fed diets using feeding method 1 or rumen fluid was incubated with maize substrate (P < 0.001). Increased production of total gas and methane was observed in feeding method 1 and maize substrate compared to those of other methods or timothy substrate (P < 0.001). Due to the inconsistent results between ruminal fermentation and gas production in this study, further research is required to estimate effects of feeding method on enteric fermentation and gas production in in vivo.

• 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.

• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.735-746
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• 2016

This study was conducted to investigate the antibacterial, antioxidant, and in vitro greenhouse gas mitigation activities of fermented Scutellaria baicalensis Georgi extract. Seven starter cultures were used, comprising four of lactic acid bacteria and three of Saccharomyces cerevisiae. Ten grams of S. baicalensis Georgi powder was diluted in 90 mL autoclaved MRS broth. Each seed culture was inoculated with 3-10% (v/v) S. baicalensis Georgi MRS broth and incubated at $30^{\circ}C$ for 48 h. Among the starter cultures used, only Lactobacillus plantarum EJ43 could withstand the fermentation conditions. This fermentation broth was dried and extracted with ethanol to assess its antibacterial, antioxidant, and in vitro methane mitigation activities. The extract of S. baicalensis Georgi fermented by L. plantarum EJ43 (SBLp) showed higher antibacterial activity (bigger clear zone) compared to the unfermented S. baicalensis Georgi extract (SB0). SBLp also presented 1.2 folds higher antioxidant activity than SB0. During in vitro rumen fermentation, SBLp showed reduction in methane production compared to SB0 or the control. In conclusion, fermentation by L. plantarum EJ43 may enhance antibacterial and antioxidant activities of S. baicalensis Georgi and decrease enteric methane production.

• Animal Bioscience
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• v.37 no.3
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• pp.405-418
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• 2024

In recent years, there has been a growing argument attributing the primary cause of global climate change to livestock industry, which has led to the perception that the livestock industry is synonymous with greenhouse gas (GHG) emissions. However, a closer examination of the global GHG emission by sector reveals that the energy sector is responsible for the majority, accounting for 76.2% of the total, while agriculture contributes 11.9%. According to data from the Food and Agriculture Organization of the United Nations (FAO), the total GHG emissions associate with the livestock supply chain amount to 14.5%. Within this, emissions from direct sources, such as enteric fermentation and livestock manure treatment, which are not part of the front and rear industries, represent only 7%. Although it is true that the increase in meat consumption driven by global population growth and rising incomes, has contributed to higher methane (CH₄) emissions resulting from enteric fermentation in ruminant animals, categorizing the livestock industry as the primary source of GHG emissions oversimplifies a complex issue and disregards objective data. Therefore, it may be a misleading to solely focus on the livestock sector without addressing the significant emissions from the energy sector, which is the largest contributor to GHG emissions. The top priority should be the objective and accurate measurement of GHG emissions, followed by the development and implementation of suitable reduction policies for each industrial sector with significant GHG emissions contributions.