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Reducing Enteric Methane Emissions from Ruminants

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A special issue of Animals (ISSN 2076-2615). This special issue belongs to the section "Animal Nutrition".

Deadline for manuscript submissions: closed (15 December 2019) | Viewed by 46272

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Special Issue Editor

Dr. Ed Charmley

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Guest Editor

The Commonwealth Scientific and Industrial Research Organisation | CSIRO Agriculture and Food, Canberra, Australia
Interests: use of technology to record hard to measure animal and environmental variables in the field, understanding livestock methane emissions from extensive grazing systems and improving the feed efficiency of ruminants

Special Issue Information

Dear Colleagues,

Worldwide ruminants play a major role in the production of meat, milk, fibre, and draught power for a growing human population, but at the same time, their sheer numbers present a threat to the global climate. As a by-product of anaerobic microbial digestive processes, ruminants produce methane, a potent greenhouse gas having 25 times the global warming potential of CO₂. It is estimated that domesticated ruminants produce about 7 gigatonnes (Gt) CO₂ equivalent per year, which is equivalent to 14.5% of total global anthropogenic GHGs. With a growing human population, coupled with increasing affluence, especially in Asia, the demand for ruminant products continues to grow. Meanwhile, in developed nations, concern regarding the environmental footprint of ruminant products is leading to reduced consumption of ruminant products. Faced with these challenges, there is a clear imperative to lower the production and intensity of methane emissions (the methane emission per unit of useful product). Science-based solutions to improve the efficiency of ruminant systems and reducing the production of methane in the rumen are leading to real possibilities for substantial reductions of GHG emissions from ruminant livestock. In this Special Issue, we will highlight the latest research in ruminant methane mitigation from a wide range of contributors from across the globe.

We invite original research papers on methods to reduce methane emissions intensity through modification of the rumen environment or the ruminant production system. Suitable topics include: Rumen microbiology and biochemistry, nutritional manipulation of methane emissions, feed additives, genetic selection for low methane animals, vaccination, antimethanogenic plants, and agricultural systems or practices that reduce enteric methane intensity, including modelling.

Dr. Ed Charmley
Guest Editor

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Keywords

methane mitigation
rumen microbiology
intensity
emissions
nutrition
genetics
cattle
sheep
goat

Published Papers (11 papers)

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Research

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17 pages, 2437 KiB

Open AccessArticle

The Reduction of Methane Production in the In Vitro Ruminal Fermentation of Different Substrates is Linked with the Chemical Composition of the Essential Oil

by Florencia Garcia, Darío Colombatto, M. Alejandra Brunetti, M. José Martínez, M. Valeria Moreno, M. Carolina Scorcione Turcato, Enrique Lucini, Georgina Frossasco and Jorge Martínez Ferrer

Animals 2020, 10(5), 786; https://doi.org/10.3390/ani10050786 - 01 May 2020

Cited by 14 | Viewed by 2882

Abstract

There is interest in identifying natural products capable of manipulating rumen microbial activity to develop new feed additives for ruminant nutrition as a strategy to reduce methane. Two trials were performed using the in vitro gas production technique to evaluate the interaction of substrate (n = 5) and additive (n = 6, increasing doses: 0, 0.3, 3, 30, and 300 µL/L of essential oils—EO—of Lippia turbinata or Tagetes minuta, and monensin at 1.87 mg/L). The two EO utilized were selected because they differ markedly in their chemical composition, especially in the proportion of oxygenated compounds. For both EO, the interaction between the substrate and additive was significant for all variables; however, the interaction behaved differently for the two EO. Within each substrate, the response was dose-dependent, without effects at a low level of EO and a negative outcome at the highest dose. The intermediate dose (30 µL/L) inhibited methane with a slight reduction on substrate digestibility, with L. turbinata being more effective than T. minuta. It is concluded that the effectiveness of the EO to reduce methane production depends on interactions between the substrate that is fermented and the additive dose that generates different characteristics within the incubation medium (e.g., pH); and thus, the chemical nature of the compounds of the EO modulates the magnitude of this response. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

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15 pages, 334 KiB

Open AccessArticle

Methane Emissions, Performance and Carcass Characteristics of Different Lines of Beef Steers Reared on Pasture and Finished in Feedlot

by Paulo Méo-Filho, Alexandre Berndt, Cintia R. Marcondes, André F. Pedroso, Leandro S. Sakamoto, Daniella F. V. Boas, Paulo H. M. Rodrigues, M. Jordana Rivero and Ives C. S. Bueno

Animals 2020, 10(2), 303; https://doi.org/10.3390/ani10020303 - 13 Feb 2020

Cited by 6 | Viewed by 3154

Abstract

The present study aimed to investigate whether different lines of a composite breed (5/8 Charolais × 3/8 Zebu), formed at different times, and genetically improved, would result in differences in animal performance, enteric methane emissions, and carcass traits. Forty-six Canchim steers (15 months, 280 ± 33 kg liveweight) from three different lines were used: old, new, and their cross. These three breed lines were considered the treatments (arranged in four randomized blocks based on initial liveweight) and were evaluated under grazing and feedlot conditions in relation to the performance and emission of enteric methane. During the grazing period, the new line was found to be superior to the old only in relation to the average daily liveweight gain (0.692 vs. 0.547 kg/day), and with no differences in relation to the cross line (0.692 vs. 0.620). In the feedlot finishing phase, only the average daily liveweight gain was significantly higher in the new line compared to the cross and old line (1.44 vs. 1.32 and 1.23 kg/day). The new and cross lines demonstrated higher dry matter intake when compared to the old line (10.25 and 10.42 vs. 9.11 kg/day), with the crossline animals demonstrating the best feed conversion. The new line showed higher enteric methane emissions compared to the old line (178 vs. 156 g/day). The line had an effect on the carcass dressing of the animals, with greater fat thickness in carcasses from the new and cross lines than the old line (4.4 and 3.8 vs. 3.2 mm). Canchim cattle selected for improved productive performance characteristics does not guarantee animals with lower methane emissions under grazing conditions; while in feedlots, can lead to increased daily feed consumption, and hence, to higher emissions of methane. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

14 pages, 249 KiB

Open AccessArticle

Gas Production, Digestibility and Efficacy of Stored or Fresh Plant Extracts to Reduce Methane Production on Different Substrates

by Abiodun Mayowa Akanmu, Abubeker Hassen and Festus Adeyemi Adejoro

Animals 2020, 10(1), 146; https://doi.org/10.3390/ani10010146 - 16 Jan 2020

Cited by 24 | Viewed by 3366

Abstract

Natural compounds such as plant secondary metabolites (PSM) can be used to replace antibiotic growth promoters as rumen modifiers. In this study, the effectiveness of stored and freshly extracted Aloe vera (AV), Azadirachta indica (AZ), Moringa oleifera (MO), Jatropha curcas (JA), Tithonia diversifolia (TD) and Carica papaya (CP) crude extract and monensin on in vitro gas and methane production, organic matter digestibility (IVOMD) and volatile fatty acids (VFA) were evaluated using a total mixed ration (TMR), lucerne or Eragrostis curvula substrates. Fresh extracts were processed from the same batch of frozen (−20 °C) plant material a few days before the trial while the stored extracts were extracted and stored at 4 °C for 12 months prior to the study. Extraction was done by solubilising 50 g freeze-dried plant material in 500 mL 100% methanol. Four mL of reconstituted 50 mg crude extract per 1000 mL distilled water was added per incubation vial, which already contained 400 mg substrate and in vitro fermentation, and gas production and IVOMD evaluation were carried out using standard procedures. Results showed that storing plant extracts for 12 months did not affect the activity or stability of metabolites present in the crude extracts, as shown by the lack of differences in total gas production (TGP) and methane produced between fresh or stored extracts across the substrates. In the TMR substrate, plant extracts increased IVOMD but did not affect TGP and methane production, whereas monensin did not have any effect. Plant extracts increased IVOMD of Eragrostis substrate and supressed methane production to a greater extent than monensin (p < 0.05). It can be concluded that storing plant extracts for up to 12 months did not compromise their efficacy. In addition, the use of 50 mg/kg of AV, AZ, MO, JA, TD and CP extract to a forage-based diet will reduce methane production while improving feed digestibility. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

11 pages, 945 KiB

Open AccessArticle

Short-Term Eating Preference of Beef Cattle Fed High Forage or High Grain Diets Supplemented with 3-Nitrooxypropanol

by Chanhee Lee, Seon-Ho Kim, Karen Beauchemin, Pietro Celi and Stéphane Duval

Animals 2020, 10(1), 64; https://doi.org/10.3390/ani10010064 - 30 Dec 2019

Cited by 9 | Viewed by 2613

Abstract

Two experiments were conducted to examine eating preference of beef cattle for diets with or without the investigative enteric methane inhibitor 3-nitrooxypropanol (3-NOP). Nine beef steers were housed in individual stalls, each equipped with two feed bunks. The first experiment (Exp. 1) was conducted with a high forage diet and each animal received a diet without 3-NOP (CON) in one bunk and a diet with 3-NOP (dNOP) in the other bunk. The second study (Exp. 2) was conducted with the same animals about 6 months after Exp. 1 where a high grain diet without (CON) or with 3-NOP (dNOP) was offered. In Exp. 1, animals initially preferred CON compared with dNOP. Feed consumption from 0 to 3, 3 to 6, and 6 to 12 h after feeding was lower for dNOP compared with CON. However, dry matter intake (DMI) and feed consumption of dNOP gradually increased during Exp. 1 such that there was no preference between CON and dNOP on day 7. In Exp. 2, there was no preference for or against dNOP. Average DMI was greater for dNOP vs. CON, but interactions between diet and day for DMI and feed consumption rates indicated that daily preference between CON and dNOP was variable. In conclusion, beef steers initially detected a difference between CON and dNOP and selected in favor of CON rather than dNOP when they had not previously been exposed to 3-NOP. However, the animals rapidly acclimatized to a diet with 3-NOP (Exp. 1) and showed no eating preference between CON and dNOP within 7 days. This lack of preference was maintained throughout Exp. 2 when the same animals were fed a high grain diet. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

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17 pages, 744 KiB

Open AccessArticle

Methane and Carbon Dioxide Emission of Beef Heifers in Relation with Growth and Feed Efficiency

by Gilles Renand, Aurélie Vinet, Virginie Decruyenaere, David Maupetit and Dominique Dozias

Animals 2019, 9(12), 1136; https://doi.org/10.3390/ani9121136 - 12 Dec 2019

Cited by 25 | Viewed by 4517

Abstract

Reducing enteric methane production and improving the feed efficiency of heifers on roughage diets are important selection objectives for sustainable beef production. The objective of the current study was to assess the relationship between different methane production and feed efficiency criteria of beef heifers fed ad libitum roughage diets. A total of 326 Charolais heifers aged 22 months were controlled in two farms and fed either a grass silage (n = 252) or a natural meadow hay (n = 74) diet. Methane (CH₄) and carbon dioxide (CO₂) emission rates (g/day) were measured with GreenFeed systems. The dry matter intake (DMI), average daily gain (ADG), CH₄ and CO₂ were measured over 8 to 12 weeks. Positive correlations were observed among body weight, DMI, ADG, CH₄ and CO₂. The residual feed intake (r_wgDMI) was not related to CH₄ or residual methane (r_wiCH₄). It was negatively correlated with methane yield (CH₄/DMI): R_p = −0.87 and −0.83. Residual gain (r_wiADG) and ADG/DMI were weakly and positively related to residual methane (r_wiCH₄): R_p = 0.21 on average. The ratio ADG/CO₂ appeared to be a useful proxy of ADG/DMI (R_p = 0.64 and 0.97) and CH₄/CO₂ a proxy of methane yield (R_p = 0.24 and 0.33) for selecting low-emitting and efficient heifers. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

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21 pages, 1051 KiB

Open AccessArticle

Volatile Fatty Acids in Ruminal Fluid Can Be Used to Predict Methane Yield of Dairy Cows

by S. Richard O. Williams, Murray. C. Hannah, Joe L. Jacobs, William J. Wales and Peter J. Moate

Animals 2019, 9(12), 1006; https://doi.org/10.3390/ani9121006 - 20 Nov 2019

Cited by 36 | Viewed by 5240

Abstract

The dry matter intake (DMI) of forage-fed cattle can be used to predict their methane emissions. However, many cattle are fed concentrate-rich diets that decrease their methane yield. A range of equations predicting methane yield exist, but most use information that is generally unavailable when animals are fed in groups or grazing. The aim of this research was to develop equations based on proportions of ruminal volatile-fatty-acids to predict methane yield of dairy cows fed forage-dominant as well as concentrate-rich diets. Data were collated from seven experiments with a total of 24 treatments, from 215 cows. Forage in the diets ranged from 440 to 1000 g/kg. Methane was measured either by open-circuit respiration chambers or a sulfur hexafluoride (SF₆) technique. In all experiments, ruminal fluid was collected via the mouth approximately four hours after the start of feeding. Seven prediction equations were tested. Methane yield (MY) was equally best predicted by the following equations: MY = 4.08 × (acetate/propionate) + 7.05; MY = 3.28 × (acetate + butyrate)/propionate + 7.6; MY = 316/propionate + 4.4. These equations were validated against independent published data from both dairy and beef cattle consuming a wide range of diets. A concordance of 0.62 suggests these equations may be applicable for predicting methane yield from all cattle and not just dairy cows, with root mean-square error of prediction of 3.0 g CH₄/kg dry matter intake. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

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13 pages, 256 KiB

Open AccessArticle

Effect of Lipid-Encapsulated Acacia Tannin Extract on Feed Intake, Nutrient Digestibility and Methane Emission in Sheep

by Festus Adeyemi Adejoro, Abubeker Hassen and Abiodun Mayowa Akanmu

Animals 2019, 9(11), 863; https://doi.org/10.3390/ani9110863 - 25 Oct 2019

Cited by 35 | Viewed by 3776

Abstract

Tannins have become important phytochemicals in ruminant production, due to their wide range of biological activities. The use of a crude extract often comes with limitations, such as reduced feed intake and fibre digestibility, which could be overcome by the use of encapsulated tannin extract. In this study, four rumen-cannulated Merino wethers were used in a 4 × 4 Latin square design to determine the effect of encapsulating Acacia mearnsii tannin extract on intake, nutrient digestibility, and methane emission. The animals were placed on one of the following diets: control diet only, diet + silvafeed (Silvafeed ByPro, 10 g/kg feed), diet + Acacia tannin extract (ATE), 40 g/kg feed), and, diet + lipid-encapsulated-ATE (palm oil encapsulated ATE, 50 g/kg feed) in 4 cycles. Wethers were offered an Eragrotis and Lucerne hay-based total mixed ration diet above maintenance requirement with forage: concentrate ratio 50:50. Silvafeed, a commercial tannin additive, was used as a positive control. Nutrient intake was not different across the treatments, but nutrient digestibility was affected by dietary additives (p < 0.05). Compared to the control, and unlike the crude extract, encapsulated-ATE and silvafeed did not reduce dry matter, organic matter, and neutral detergent fibre digestibility. While the overall N-retention and total N-excretion (g/d) were not affected by dietary additives, ATE and encapsulated-ATE diets reduced urine-N excretion (g/d) and only a slight reduction was observed in silvafeed diet. The faecal-N proportion was highest in the ATE diet (388 g/kg N-intake), followed by encapsulated-ATE (317 g/kg), and silvafeed (267 g/kg), with the control diet having the lowest proportion (230 g/kg). The acetate:propionate (A:P) ratio reduced as a result of the inclusion of dietary additives with crude ATE and silvafeed having lower A:P ratio compared to the control diet. Methane production expressed in g/kg dry matter (DM) intake was reduced by 12%, 30% and 19% in the silvafeed, crude ATE and encapsulated-ATE diets, respectively (p < 0.05). The reduced methane production with higher neutral detergent fibre (NDF) digestibility in the encapsulated-ATE, compared to the crude-ATE, confirms that encapsulated-tannin can be used as an additive in ruminant diets. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

14 pages, 591 KiB

Open AccessArticle

Nitroethanol in Comparison with Monensin Exhibits Greater Feed Efficiency Through Inhibiting Rumen Methanogenesis More Efficiently and Persistently in Feedlotting Lambs

by Zhen-Wei Zhang, Yan-Lu Wang, Yong-Yan Chen, Wei-Kang Wang, Luo-Tong Zhang, Hai-Ling Luo and Hong-Jian Yang

Animals 2019, 9(10), 784; https://doi.org/10.3390/ani9100784 - 11 Oct 2019

Cited by 7 | Viewed by 2612

Abstract

This study was conducted to determine the dietary supplemental effects of nitroethanol (NEOH) in comparison with monensin on growth performance and estimated methane (CH₄) production in feedlotting lambs. Sixty male, small-tailed Chinese Han lambs were arranged at random into three dietary treatment groups: (1) a basal control diet (CTR), (2) the basal diet added with 40 mg/kg monensin (MON), (3) the basal diet added with 277 mg/kg nitroethanol (NEOH). During the 32-day lamb feeding, monensin and nitroethanol were added in period 1 (day 0–16) and then withdrawn in the subsequent period 2 (day 17–32) to determine their withdrawal effects. The average daily gain (ADG) and feed conversion rate in the whole period ranked: NEOH > MON > CTR (p < 0.01), suggesting that the dietary addition of NEOH in comparison with monensin presented a more lasting beneficial effect on feed efficiency. Methane emission was estimated with rumen VFA production and gross energy intake. Both monensin and NEOH addition in comparison with the control remarkably decreased CH₄ emission estimate (24.0% vs. 26.4% decrease; p < 0.01) as well as CH₄ emission per kg ADG (8.7% vs. 14.0% decrease; p < 0.01), but the NEOH group presented obvious lasting methanogenesis inhibition when they were withdrawn in period 2. Moreover, the in vitro methanogenic activity of rumen fluids was also decreased with monensin or NEOH addition (12.7% vs. 30.5% decrease; p < 0.01). In summary, the dietary addition of NEOH in comparison with monensin presented a greater promoting effect on growth performance in feedlotting lambs by inhibiting rumen methanogenesis more efficiently and persistently. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

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11 pages, 819 KiB

Open AccessArticle

Rumen and Fecal Microbial Community Structure of Holstein and Jersey Dairy Cows as Affected by Breed, Diet, and Residual Feed Intake

by Samantha J. Noel, Dana W. Olijhoek, Farran Mclean, Peter Løvendahl, Peter Lund and Ole Højberg

Animals 2019, 9(8), 498; https://doi.org/10.3390/ani9080498 - 29 Jul 2019

Cited by 38 | Viewed by 5176

Abstract

Identifying factors that influence the composition of the microbial population in the digestive system of dairy cattle will be key in regulating these populations to reduce greenhouse gas emissions. In this study, we analyzed rumen and fecal samples from five high residual feed intake (RFI) Holstein cows, five low RFI Holstein cows, five high RFI Jersey cows and five low RFI Jersey cows, fed either a high-concentrate diet (expected to reduce methane emission) or a high-forage diet. Bacterial communities from both the rumen and feces were profiled using Illumina sequencing on the 16S rRNA gene. Rumen archaeal communities were profiled using Terminal-Restriction Fragment Length Polymorphism (T-RFLP) targeting the mcrA gene. The rumen methanogen community was influenced by breed but not by diet or RFI. The rumen bacterial community was influenced by breed and diet but not by RFI. The fecal bacterial community was influenced by individual animal variation and, to a lesser extent, by breed and diet but not by RFI. Only the bacterial community correlated with methane production. Community differences seen in the rumen were reduced or absent in feces, except in the case of animal-to-animal variation, where differences were more pronounced. The two cattle breeds had different levels of response to the dietary intervention; therefore, it may be appropriate to individually tailor methane reduction strategies to each cattle breed. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

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Review

Jump to: Research

12 pages, 1736 KiB

Open AccessReview

The Role of Chitosan as a Possible Agent for Enteric Methane Mitigation in Ruminants

by Rafael Jiménez-Ocampo, Sara Valencia-Salazar, Carmen Elisa Pinzón-Díaz, Esperanza Herrera-Torres, Carlos Fernando Aguilar-Pérez, Jacobo Arango and Juan Carlos Ku-Vera

Animals 2019, 9(11), 942; https://doi.org/10.3390/ani9110942 - 09 Nov 2019

Cited by 18 | Viewed by 5435

Abstract

Livestock production is a main source of anthropogenic greenhouse gases (GHG). The main gases are CH₄ with a global warming potential (GWP) 25 times and nitrous oxide (N₂O) with a GWP 298 times, that of carbon dioxide (CO₂) arising from enteric fermentation or from manure management, respectively. In fact, CH₄ is the second most important GHG emitted globally. This current scenario has increased the concerns about global warming and encouraged the development of intensive research on different natural compounds to be used as feed additives in ruminant rations and modify the rumen ecosystem, fermentation pattern, and mitigate enteric CH₄. The compounds most studied are the secondary metabolites of plants, which include a vast array of chemical substances like polyphenols and saponins that are present in plant tissues of different species, but the results are not consistent, and the extraction cost has constrained their utilization in practical animal feeding. Other new compounds of interest include polysaccharide biopolymers such as chitosan, mainly obtained as a marine co-product. As with other compounds, the effect of chitosan on the rumen microbial population depends on the source, purity, dose, process of extraction, and storage. In addition, it is important to identify compounds without adverse effects on rumen fermentation. The present review is aimed at providing information about chitosan for dietary manipulation to be considered for future studies to mitigate enteric methane and reduce the environmental impact of GHGs arising from livestock production systems. Chitosan is a promising agent with methane mitigating effects, but further research is required with in vivo models to establish effective daily doses without any detrimental effect to the animal and consider its addition in practical rations as well as the economic cost of methane mitigation. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

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18 pages, 1353 KiB

Open AccessReview

Potential of Molecular Weight and Structure of Tannins to Reduce Methane Emissions from Ruminants: A Review

by Isaac A. Aboagye and Karen A. Beauchemin

Animals 2019, 9(11), 856; https://doi.org/10.3390/ani9110856 - 23 Oct 2019

Cited by 92 | Viewed by 6385

Abstract

There is a need to reduce enteric methane (CH₄) to ensure the environmental sustainability of ruminant production systems. Tannins are naturally found in both tropical and temperate plants, and have been shown to consistently decrease urinary nitrogen (N) excretion when consumed by ruminants. However, the limited number of in vivo studies conducted indicates that the effects of tannins on intake, digestibility, rumen fermentation, CH₄ production and animal performance vary depending on source, type, dose, and molecular weight (MW). There are two main types of tannin in terrestrial plants: condensed tannin (CT; high MW) and hydrolysable tannin (HT; low MW). Consumption of CT and HT by ruminants can reduce N excretion without negatively affecting animal performance. High MW tannins bind to dietary protein, while low MW tannins affect rumen microbes, and thus, irrespective of type of tannin, N excretion is affected. The structure of high MW tannin is more diverse compared with that of low MW tannin, which may partly explain the inconsistent effects of CT on CH₄ production reported in in vivo studies. In contrast, the limited number of in vivo studies with low MW HT potentially shows a consistent decrease in CH₄ production, possibly attributed to the gallic acid subunit. Further in vivo studies are needed to determine the effects of tannins, characterized by MW and structural composition, on reducing CH₄ emissions and improving animal performance in ruminants. Full article

(This article belongs to the Special Issue Reducing Enteric Methane Emissions from Ruminants)

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