A Review of 3-Nitrooxypropanol for Enteric Methane Mitigation from Ruminant Livestock

Methane (CH4) from enteric fermentation accounts for 3 to 5% of global anthropogenic greenhouse gas emissions, which contribute to climate change. Cost-effective strategies are needed to reduce feed energy losses as enteric CH4 while improving ruminant production efficiency. Mitigation strategies need to be environmentally friendly, easily adopted by producers and accepted by consumers. However, few sustainable CH4 mitigation approaches are available. Recent studies show that the chemically synthesized CH4 inhibitor 3-nitrooxypropanol is one of the most effective approaches for enteric CH4 abatement. 3-nitrooxypropanol specifically targets the methyl-coenzyme M reductase and inhibits the final catalytic step in methanogenesis in rumen archaea. Providing 3-nitrooxypropanol to dairy and beef cattle in research studies has consistently decreased enteric CH4 production by 30% on average, with reductions as high as 82% in some cases. Efficacy is positively related to 3-NOP dose and negatively affected by neutral detergent fiber concentration of the diet, with greater responses in dairy compared with beef cattle when compared at the same dose. This review collates the current literature on 3-nitrooxypropanol and examines the overall findings of meta-analyses and individual studies to provide a synthesis of science-based information on the use of 3-nitrooxypropanol for CH4 abatement. The intent is to help guide commercial adoption at the farm level in the future. There is a significant body of peer-reviewed scientific literature to indicate that 3-nitrooxypropanol is effective and safe when incorporated into total mixed rations, but further research is required to fully understand the long-term effects and the interactions with other CH4 mitigating compounds.

Mitigating Ruminant Methane: Exploring the Commercialisation of Technologies for Reducing Livestock Methane Emissions

<p>Climate change is a global issue requiring unified action. Methane gas is a major component of greenhouse gas emissions contributing to global warming. This project is exploring the commercial potential of Pastoral Greenhouse Gas Research Consortium (PGgRc) developed technologies designed to mitigate the largest source of agricultural methane emissions. These technologies are methane vaccines and inhibitors targeting emissions from enteric fermentation in ruminant livestock. The two technologies share functional aspects but require different administration and upkeep. As novel technologies designed for a developing market the commercial potential of PGgRc’s methane vaccines and inhibitors is uncertain. To validate the potential methane mitigation products this project focuses on farmer adoption and interaction with the technologies. Interviews with farmers around New Zealand have been used to identify the strengths and weaknesses of methane vaccines and inhibitors from the perspective of the end user. A thematic analysis of the transcribed data highlighted various concerns among the participating farmers and provides a map of areas needing further investigation when moving forward with developing the technologies. Of key importance was the value methane vaccines and inhibitors offered the participants. Currently, methane mitigation offers no financial benefits to participants and good feelings about acting against climate change are not substantial enough to mitigate purchase and administration costs. There is potential that using PGgRc’s methane vaccines and inhibitors could improve livestock productivity, but it is yet to be verified based on current testing and development. Establishing that using the technologies leads to increased live weight gain or milk and wool production could provide profitability benefits that farmers would value. This hinges on any benefits providing substantial enough gains to the farmer to offset the purchase and administration costs. If no productivity benefits are identified government regulations creating a methane cost or subsidising the technologies could be necessary for methane vaccines and inhibitors to have value within the agricultural sector. Alternatively, if consumer purchasing behaviour shifts in favour of low emissions products the agricultural sector will need to shift production methods to remain competitive in the new market environment. PGgRc aims to employ a licensing business model using the methane vaccine and inhibitor IP they possess. Partnering with an experienced company would provide PGgRc with the market knowledge and manufacturing capabilities producing their technologies requires. As part of their development strategy they aim to develop their technology to a proof of concept stage before forming any production partnerships. This project highlights the critical factors for successfully commercialising PGgRc’s technologies. It is designed to guide the continued development of the methane mitigation technologies and help shape PGgRc’s market approach.</p>

Mitigating Ruminant Methane: Exploring the Commercialisation of Technologies for Reducing Livestock Methane Emissions

<p>Climate change is a global issue requiring unified action. Methane gas is a major component of greenhouse gas emissions contributing to global warming. This project is exploring the commercial potential of Pastoral Greenhouse Gas Research Consortium (PGgRc) developed technologies designed to mitigate the largest source of agricultural methane emissions. These technologies are methane vaccines and inhibitors targeting emissions from enteric fermentation in ruminant livestock. The two technologies share functional aspects but require different administration and upkeep. As novel technologies designed for a developing market the commercial potential of PGgRc’s methane vaccines and inhibitors is uncertain. To validate the potential methane mitigation products this project focuses on farmer adoption and interaction with the technologies. Interviews with farmers around New Zealand have been used to identify the strengths and weaknesses of methane vaccines and inhibitors from the perspective of the end user. A thematic analysis of the transcribed data highlighted various concerns among the participating farmers and provides a map of areas needing further investigation when moving forward with developing the technologies. Of key importance was the value methane vaccines and inhibitors offered the participants. Currently, methane mitigation offers no financial benefits to participants and good feelings about acting against climate change are not substantial enough to mitigate purchase and administration costs. There is potential that using PGgRc’s methane vaccines and inhibitors could improve livestock productivity, but it is yet to be verified based on current testing and development. Establishing that using the technologies leads to increased live weight gain or milk and wool production could provide profitability benefits that farmers would value. This hinges on any benefits providing substantial enough gains to the farmer to offset the purchase and administration costs. If no productivity benefits are identified government regulations creating a methane cost or subsidising the technologies could be necessary for methane vaccines and inhibitors to have value within the agricultural sector. Alternatively, if consumer purchasing behaviour shifts in favour of low emissions products the agricultural sector will need to shift production methods to remain competitive in the new market environment. PGgRc aims to employ a licensing business model using the methane vaccine and inhibitor IP they possess. Partnering with an experienced company would provide PGgRc with the market knowledge and manufacturing capabilities producing their technologies requires. As part of their development strategy they aim to develop their technology to a proof of concept stage before forming any production partnerships. This project highlights the critical factors for successfully commercialising PGgRc’s technologies. It is designed to guide the continued development of the methane mitigation technologies and help shape PGgRc’s market approach.</p>

Lovastatin as a supplement to mitigate rumen methanogenesis: an overview

Methane from enteric fermentation is the gas with the greatest environmental impact emitted by ruminants. Lovastatin (Lv) addition to feedstocks could be a strategy to mitigate rumen methane emissions via decreasing the population of methanogenic archaea (MA). Thus, this paper provides the first overview of the effects of Lv supplementation, focusing on the inhibition of methane production, rumen microbiota, and ruminal fermentation. Results indicated that Lv treatment had a strong anti-methanogenic effect on pure strains of MA. However, there are uncertainties from in vitro rumen fermentation trials with complex substrates and rumen inoculum.Solid-state fermentation (SSF) has emerged as a cost-effective option to produce Lv. In this way, SSF of agricultural residues as an Lv-carrier supplement in sheep and goats demonstrated a consistent decrease in ruminal methane emissions. The experimental evidence for in vitro conditions showed that Lv did not affect the volatile fatty acids (VFA). However, in vivo experiments demonstrated that the production of VFA was decreased. Lv did not negatively affect the digestibility of dry matter during in vitro and in vivo methods, and there is even evidence that it can induce an increase in digestibility. Regarding the rumen microbiota, populations of MA were reduced, and no differences were detected in alpha and beta diversity associated with Lv treatment. However, some changes in the relative abundance of the microbiota were induced. Further studies are recommended on: (i) Lv biodegradation products and stability, as well as its adsorption onto the solid matter in the rumen, to gain more insight on the “available” or effective Lv concentration; and (ii) to determine whether the effect of Lv on ruminal fermentation also depends on the feed composition and different ruminants.

Inventarisasi potensi emisi metana (CH4) pada peternakan sapi perah di Kecamatan Pujon, Kabupaten Malang

<p class="MDPI17abstract"><strong>Objective: </strong>The methane emissions in ruminants such as dairy cows was one of the causes of climate change. The aimed of this study was to make an inventory of methane emissions from dairy farms in Pujon District. The methane emission data inventory was expected to assist the government in making policies as an effort to mitigation of methane emissions.</p><p class="MDPI17abstract"><strong>Methods: </strong>The secondary data used in this study were obtained from journals, books, literature related to research, and data from the Central Statistics Agency (BPS). Methane emissions was calculated using the Tier 1 method according to IPCC reference. The reason for the inventory using the tier 1 method was caused that the specific data related to emissions on dairy cows in Malang Regency were not available. The data obtained were processed descriptively.<strong></strong></p><p class="MDPI17abstract"><strong>Results</strong><strong>: </strong>The data obtained shown that the population of dairy cows in Pujon District from 2013-2015 has increased, in 2016 it experienced a significant decline, namely 14.2%, then from 2017-2019 it continued to decline. Methane emissions from enteric fermentation from 2013-2019 averaged 23.13 Gg CO₂-eq / year. Methane emissions from manure management in dairy cows in Pujon District from 2013-2019 were an average of 11.75 Gg CO₂-eq / year. The highest methane emissions were in 2015, and the lowest was in 2019.<strong></strong></p><strong>Conclusions: </strong>Based on the results of the study, it can be concluded that methane emissions from dairy cows in Pujon District increased from 2013-2015, there was a significant reduction in emissions in 2016 – 2019. Feeding with balanced nutrients, using ingredients of concentrated and forage containing good nutrients quality is an effort to mitigate methane that can applied by farmers.

Role of emission sources and atmospheric sink on the seasonal cycle of CH₄ and δ¹³-CH₄: analysis based on the atmospheric chemistry transport model TM5

This study investigates the contribution of different CH4 sources to the seasonal cycle of 𝛿13C during years 2000–2012 using the TM5 atmospheric transport model. The seasonal cycles of anthropogenic emissions from two versions of the EDGAR inventories, v4.3.2 and v5.0 are examined. Those includes emissions from Enteric Fermentation and Manure Management (EFMM), rice cultivation and residential sources. Those from wetlands obtained from LPX-Bern v1.4 are also examined in addition to other sources such as fires and ocean sources. We use spatially varying isotopic source signatures for EFMM, coal, oil and gas, wetlands, fires and geological emission and for other sources a global uniform value. We analysed the results as zonal means for 30° latitudinal bands. Seasonal cycles of 𝛿13C are found to be an inverse of CH4 cycles in general, with a peak-to-peak amplitude of 0.07–0.26 ‰. However, due to emissions, the phase ellipses do not form straight lines, and the anti-correlations between CH4 and 𝛿13C are weaker (−0.35 to −0.91) in north of 30° S. We found that wetland emissions are the dominant driver in the 𝛿13C seasonal cycle in the Northern Hemisphere and Tropics, such that the timing of 𝛿13C seasonal minimum is shifted by ∼90 days in 60° N–90° N from the end of the year to the beginning of the year when seasonality of wetland emissions is removed. The results also showed that in the Southern Hemisphere Tropics, emissions from fires contribute to the enrichment of 𝛿13C in July–October. In addition, we also compared the results against observations from the South Pole, Antarctica, Alert, Nunavut, Canada and Niwot Ridge, Colorado, USA. In light of this research, comparison to the observation showed that the seasonal cycle of EFMM emissions in EDGAR v5.0 inventory is more realistic than in v4.3.2. In addition, the comparison at Alert showed that modelled 𝛿13C amplitude was approximately half of the observations, mainly because the model could not reproduce the strong depletion in autumn. This indicates that CH4 emission magnitude and seasonal cycle of wetlands may need to be revised. Results from Niwot Ridge indicate that in addition to biogenic emissions, the proportion of biogenic to fossil based emissions may need to be revised.

Greenhouse gas emissions from livestock and mitigation options in Nigeria

Greenhouse gases are becoming devastating on agriculture and environment because of its effect on climate and global warming. The aim of this review is to provide update on livestock greenhouse gases emission and rekindle available mitigation strategies. Recently, global warming and climate change have become one of the most discussed issues globally because of their negative effect on ecosystem worldwide. The livestock sub-sector as a major source of greenhouse gas emission, has been identified to contribute substantially to the recent rise in global warming and climate change. Livestock, most importantly ruminants plays a major role in the emission of methane, one of the potent greenhouse gases. This methane is usually released through enteric fermentation in animals and manure management system, though the latter account for smaller quantity. Estimate of methane emission inventory from livestock in Nigeria showed that 96.15 % of methane produced by livestock was by ruminants with cattle alone accounting for 74.06 %. With this background, strategies to date for reducing methane emissions should centre on ruminant. Efforts to reduce methane emissions from enteric fermentation generally focus on options for improving production efficiency. This has been demonstrated with intensive animal production systems. However, in Nigeria, this system has been successful only for non-ruminants while the extensive and semi extensive systems are being practiced for ruminants. In view of this, options for reducing emissions must be selected to be consistent with country-specific circumstances. Those circumstances should include animal management practices (including cultural traditions), nutrition and economic development priorities. Les gaz à effet de serre deviennent dévastateurs de l'agriculture et de l'environnement en raison de son effet sur le climat et le réchauffement de la planète. L'objectif de cet examen est de fournir une mise à jour sur les stratégies d'atténuation disponibles des gaz à effet de serre de bétail. Récemment, le réchauffement climatique et le changement climatique sont devenus l'une des questions les plus discutées à l'échelle mondiale en raison de leur effet négatif sur l'écosystème mondial. Le sous-secteur de l'élevage en tant que source majeure d'émissions de gaz à effet de serre, a été identifié pour contribuer de manière substantielle à la hausse récente du réchauffement de la planète et du changement climatique. Le bétail, plus important encore, les ruminants jouent un rôle majeur dans l'émission de méthane, l'un des gaz à effet de serre puissants. Ce méthane est généralement libéré par la fermentation entérique chez les animaux et le système de gestion de fumier, bien que ces derniers représentent une plus petite quantité. L'estimation des stocks d'émissions de méthane provenant du bétail au Nigéria a montré que 96,15% de méthane produites par le bétail étaient par des ruminants avec des bovins à eux-mêmes représentant 74,06%. Avec ce contexte, des stratégies à ce jour pour réduire les émissions de méthane doivent être centrées sur le ruminant. Les efforts visant à réduire les émissions de méthane de la fermentation entérique se concentrent généralement sur les options d'amélioration de l'efficacité de la production. Cela a été démontré avec des systèmes de production d'animaux intensifs. Cependant, au Nigéria, ce système n'a abouti que pour les non-ruminants tandis que les systèmes étendus et semi-étendus sont pratiqués pour les ruminants. Compte tenu de cela, les options de réduction des émissions doivent être sélectionnées pour être cohérentes avec des circonstances spécifiques à chaque pays. Ces circonstances devraient inclure des pratiques de gestion des animaux (y compris des traditions culturelles), des priorités de nutrition et de développement économique

The rumen microbiome inhibits methane formation through dietary choline supplementation

Enteric fermentation from ruminants is a primary source of anthropogenic methane emission. This study aims to add another approach for methane mitigation by manipulation of the rumen microbiome. Effects of choline supplementation on methane formation were quantified in vitro using the Rumen Simulation Technique. Supplementing 200 mM of choline chloride or choline bicarbonate reduced methane emissions by 97–100% after 15 days. Associated with the reduction of methane formation, metabolomics analysis revealed high post-treatment concentrations of ethanol, which likely served as a major hydrogen sink. Metagenome sequencing showed that the methanogen community was almost entirely lost, and choline-utilizing bacteria that can produce either lactate, ethanol or formate as hydrogen sinks were enriched. The taxa most strongly associated with methane mitigation were Megasphaera elsdenii and Denitrobacterium detoxificans, both capable of consuming lactate, which is an intermediate product and hydrogen sink. Accordingly, choline metabolism promoted the capability of bacteria to utilize alternative hydrogen sinks leading to a decline of hydrogen as a substrate for methane formation. However, fermentation of fibre and total organic matter could not be fully maintained with choline supplementation, while amino acid deamination and ethanolamine catabolism produced excessive ammonia, which would reduce feed efficiency and adversely affect live animal performance.

Greenhouse Gas Emissions from Agriculture in EU Countries—State and Perspectives

Agriculture is one of the main sources of greenhouse gas (GHG) emissions and has great potential for mitigating climate change. The aim of this study is to analyze the amount, dynamics of changes, and structure of GHG emissions from agriculture in the EU in the years 2005–2018. The research based on data about GHG collected by the European Environment Agency. The structure of GHG emissions in 2018 in the EU is as follows: enteric fermentation (45%), agricultural soils (37.8%), manure management (14.7%), liming (1.4%), urea application (1%), and field burning of agricultural residues (0.1%). Comparing 2018 with the base year, 2005, emissions from the agricultural sector decreased by about 2%, which is less than the assumed 10% reduction of GHG emissions in the non-emissions trading system (non-ETS) sector. The ambitious goals set by the EU for 2030 assume a 30% reduction in the non-ETS sector. This will require a significant reduction in GHG emissions from agriculture. Based on the analysis of the GHG emission structure and available reduction techniques, it was calculated that in this period, it should be possible to reduce emissions from agriculture by about 15%.

Macroalgae Microbiomes May Hold the Key to Reducing Methane Emissions From Ruminant Livestock

Ruminant mammals extract nutrients from plant-based food through fermentation in the rumen; fiber and starch are pre-digested by microorganisms and methane is produced as a by-product, which released into the atmosphere acts as a potent greenhouse gas. In an effort to reduce enteric methanogenesis, dietary additives for ruminants have been investigated, and marine macroalgae have proven particularly promising, e.g., the inclusion of 0.2% dry matter of the red alga A. taxiformis into cow feed decreased in vivo methane production by up to 98%. Thus, if globally applied, the addition of algae in ruminant diets could revolutionize the management of greenhouse gas emissions across the livestock sector. However, the ozone-depleting nature of halogen compounds produced in Asparagopsis sp. and the reported adverse health impacts on humans, along with impracticability issues and the difficulty to produce, commercialize and distribute algae widely, has sown some doubt on the feasibility of using macroalgae as methane mitigation instruments. To circumvent such obstacles, and taking into account the paradigm that eukaryotic hosts cannot be understood without considering interactions with their associated microbiome, the exploration of marine algae associated microorganisms is anticipated. Following the notion that in the close and intimate relationships between algae-hosts and their microbiota the origin of chemical response mechanisms is often unclear, and that compounds initially assigned to algae have previously been shown to stem from host-associated microbes, it is not unreasonable to think that these may be involved in the antimethanogenic effects of marine algae in the rumen. Once identified, such microorganisms could lead to antimethanogenic feed additives, and reduce enteric methanogenesis from livestock ruminants substantially. This review is three-fold: it provides a brief, historic overview of macroalgae as feed supplements for ruminants, sums up the difficulties related to using whole-macroalgae as large-scale antimethanogenic feed additives, and describes the macroalga microbiome, including its potential to serve as an antimethanogen for enteric fermentation.