Effect of condensed tannins from Leucaena leucocephala on rumen fermentation, methane production and population of rumen protozoa in heifers fed low-quality forage

Environmental impact of phytobiotic additives on greenhouse gas emission reduction, rumen fermentation manipulation, and performance in ruminants: an updated review

Ruminal fermentation is a natural process involving beneficial microorganisms that contribute to the production of valuable products and efficient nutrient conversion. However, it also leads to the emission of greenhouse gases, which have detrimental effects on the environment and animal productivity. Phytobiotic additives have emerged as a potential solution to these challenges, offering benefits in terms of rumen fermentation modulation, pollution reduction, and improved animal health and performance. This updated review aims to provide a comprehensive understanding of the specific benefits of phytobiotic additives in ruminant nutrition by summarizing existing studies. Phytobiotic additives, rich in secondary metabolites such as tannins, saponins, alkaloids, and essential oils, have demonstrated biological properties that positively influence rumen fermentation and enhance animal health and productivity. These additives contribute to environmental protection by effectively reducing nitrogen excretion and methane emissions from ruminants. Furthermore, they inhibit microbial respiration and nitrification in soil, thereby minimizing nitrous oxide emissions. In addition to their environmental impact, phytobiotic additives improve rumen manipulation, leading to increased ruminant productivity and improved quality of animal products. Their multifaceted properties, including anthelmintic, antioxidant, antimicrobial, and immunomodulatory effects, further contribute to the health and well-being of both animals and humans. The potential synergistic effects of combining phytobiotic additives with probiotics are also explored, highlighting the need for further research in this area. In conclusion, phytobiotic additives show great promise as sustainable and effective solutions for improving ruminant nutrition and addressing environmental challenges.

Flavonoids from citrus peel display potential synergistic effects on inhibiting rumen methanogenesis and ammoniagenesis: a microbiome perspective

Flavonoids have been recognized as potential phytochemicals to reduce enteric methane (CH4) production and improve rumen nitrogen efficiency in ruminants. We evaluated whether naringin, hesperidin, their combination, or a mixed citrus flavonoid extract (CFE) as additives can inhibit methanogenesis and ammoniagenesis in dairy cows using an in vitro rumen batch refermentation system. The rumen inocula from dairy cows were incubated in batch cultures with five groups: no addition (CON), hesperidin (20 g/kg DM), naringin (20 g/kg DM), hesperidin + naringin (10 g/kg DM of hesperidin + 10 g/kg DM of naringin), and CFE (20 g/kg DM). The combination of naringin plus hesperidin and CFE achieved greater reductions in CH4 and ammonia production compared to either naringin or hesperidin alone. Microbiome analysis revealed that the decrease in CH4 emissions may have been caused by both the direct inhibitory impact of citrus flavonoids on Methanobrevibacter and a simultaneous decrease in protozoa Isotricha abundance. The relatively lower proportion of Entodinium in naringin plus hesperidin or CFE was responsible for the lower ammonia concentration. These results suggest that citrus flavonoids possess potential synergistic effects on mitigating ruminal CH4 emissions by cows and improving nitrogen utilization.

Fermentation Patterns, Methane Production and Microbial Population under In Vitro Conditions from Two Unconventional Feed Resources Incorporated in Ruminant Diets

In this study, four experimental treatments were evaluated: (T1) alfalfa hay + concentrate, (50:50%, DM); (T2) alfalfa hay + Leucaena leucocephala + concentrate, (30:20:50%, DM); (T3) alfalfa hay + prickly pear + concentrate, (30:20:50%, DM); and (T4) alfalfa hay + Leucaena leucocephala + prickly pear + concentrate, (30:10:10:50%, DM). NH3-N concentrations in T2 and T4 decreased when replaced with alfalfa hay in 20 and 10%, respectively. Treatments did not affect the concentration of total volatile fatty acids (TVFA) between T3 and T4 (p > 0.05), while the concentrations among T1 and T2 were different (p < 0.05). T2 showed a reduction of 25.5% in the methane production when compared to T1 (p < 0.05). The lowest concentrations of protozoa were observed in T2 and T4, which contained Leucaena leucocephala (T2) and Leucaena leucocephala + prickly pear (T4) (p < 0.05). The highest concentration of total methanogens was recorded in T1 and was different in T2, T3, and T4 (p < 0.05). Leucaena leucocephala, at an inclusion percentage of 20%, decreased the methane when compared to T1, whereas prickly pear increased methane production in relation to T1.

Effects of the Inclusion of Ground Pouteria sapota Kernel on Intake, Digestibility, and Growth Performance in Lambs

This study determined the effect of replacing ground corn and soybean meal with ground Pouteria sapota kernel (PSSM) in lamb diets on nutrient intake and digestibility, performance, and carcass traits. Twenty-one male hair sheep lambs with an average body weight of 22 ± 3.5 kg were randomly assigned to three treatment diets containing PSSM at 0, 10, and 20% of the total dry matter (DM) inclusion. The study lasted 60 days, which included 15 days for adaption and 45 days for sample collection. The PSSM inclusion did not affect intake or performance (p > 0.05). However, ether extract (EE) digestibility linearly increased (p < 0.0001), while crude protein (CP) and acid detergent fiber (ADF) linearly decreased. Final body weight, total weight gain, average daily weight gain, feeding efficiency, and carcass traits were not affected by PSSM inclusion. In conclusion, these results suggest that PSSM can replace up to 200 g/kg DM of ground corn and soybean meal without affecting intake or animal performance.

Effects of replacing Brachiaria hay with either Desmodium intortum or dairy concentrate on animal performance and enteric methane emissions of low-yielding dairy cows

In Africa, cattle are often fed low quality tropical roughages resulting in low-yielding animals with high methane (CH4) emission intensity (EI, g CH4/per unit of product). Supplementation with protein is known to improve the nutritive value of the otherwise low-quality diets. However, animal nutrition studies in East Africa that are accompanied by CH4 emission measurements are lacking. Thus, an animal experiment was conducted to quantify the effect of supplementing cattle fed mainly on low-quality Urochloa brizantha hay (control diet; CON; crude protein (CP) = 7.4%) or supplemented with either a tannin-rich leguminous fodder, Desmodium intortum hay (DES) or a commercial dairy concentrate (CUBES) on voluntary dry matter intake (DMI), nutrient apparent total tract digestibility, nitrogen (N) retention, enteric CH4 production and animal performance (milk and average daily gain). Twelve mid-lactating crossbred (Friesian × Boran) cows (initial liveweight = 335 kg) were used in a 3×3 (Period × Diet) Latin square design with each period running for four weeks. Compared to CON, DES decreased nutrient (DM, OM, CP) intake, apparent total tract digestibility and daily milk yield. In contrast, CUBES increased nutrient intake and animal performance compared to CON, while nutrients’ apparent total tract digestibility was not different, except for CP digestibility that increased. Compared to CON, DES and CUBES improved overall N retention by the animals as a proportion of N intake. The DES diet compared with CON and CUBES, shifted the proportion of N excretion via urine to the fecal route, likely because of its tannin content. Both DES and CUBES, compared to CON, reduced methane yield (MY, g CH4/kg DMI) by 15% and 9%, respectively. The DES diet reduced absolute enteric CH4 emissions by 26% while CUBES increased emissions by 11% compared to CON. Based on the present findings, high supplementation levels (&gt;50%) of Desmodium intortum hay is not recommended especially when the basal diet is low in CP content. Supplementation with lower levels of better managed Desmodium intortum forage however, need to be investigated to establish optimal inclusion levels that will improve animal productivity and reduce environmental impact of livestock in smallholder tropical contexts.

Therapeutic Effect and Immune Changes after Treatment of Hymenolepis nana-Infected BALB/c Mice with Compounds Isolated from Leucaena leucocephala

Simple Summary

This article is mainly about the development of natural medicines against the zoonotic tapeworm (Hymenolepis nana), which is caused by tapeworm eggs in infected mice, through the isolation of the components of jumbay (Leucaena leucocephala). This study allowed for an understanding of the drug therapy through the testing of these isolated components in vitro and in vivo. The authors assessed the survival and motility, and they confirmed that the two components had good effects against tapeworm. One of these components has a promising therapeutic effect in tapeworm-infected mice in the response to egg production, worm numbers, and immune responses. This article highlights the immune-enhancing and therapeutic effects of 13²-hydroxy-(13²-S)-pheophytin a against tapeworms in infected mice.

Abstract

Background/Purpose: Hymenolepis nana is globally distributed. Leucaena leucocephala has been studied as a treatment, including the nematodes and protozoa, but no research results are related to cestodes. Therefore, the aim of this study was to target H. nana. Methods: The natural components of L. leucocephala were isolated and added to H. nana, which was cultured in vitro, to observe changes in the mortality, motility, and morphology. BALB/c male mice infected with H. nana were treated with effective components of L. leucocephala for 10 days, and the changes were recorded. After the mice were sacrificed, the spleen weight was measured, and a primary culture was performed for the subsequent cytokine and chemokine testing. Results: The experiment found that 13²-hydroxy-(13²-S)-pheophytin a and aristophyll-C have clear cestocidal effects in vitro. 13²-hydroxy-(13²-S)-pheophytin a has been shown to be effective at reducing parasite populations and eliciting host immune responses in vivo. IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, MCP-1, IFN-γ, TNF-α, MIP-1α, and GM-CSF in 13²-hydroxy-(13²-S)-pheophytin a were significantly increased after stimulation, while IL-1α, IL-1β, IL-3, IL-12p70, and RANTES were unchanged. Conclusions: The investigation shows that components of L. leucocephala have actual cestocidal activity against H. nana.

Effect of Various Feed Additives on the Methane Emissions from Beef Cattle Based on an Ammoniated Palm Frond Feeds

Methane gas has a very significant contribution to the increase in greenhouse gases (GHG) globally. The livestock sector, especially ruminants, causes the issue of increasing GHG concentrations. The chapter presents the issue of reducing methane gas production from cattle. Various experiments to reduce methane gas production from ruminants have been carried out and have shown varying results. This series of results of the author\'s research on reducing methane gas production in livestock in beef cattle based on agriculture by-product to animal feed is addressed with this background. Agriculture by-products such as oil palm fronds and rice straw can be used to feed beef cattle in Indonesia. However, agriculture by-product as animal feed can reduce feed efficiency and increase methane gas production due to the high lignin content. Therefore, various alternatives are carried out to optimize the utilization of this plantation waste. One of them is the use of feed additives and methanogenesis inhibitors. The author\'s series of research using feed additives (direct-fed microbial) and various methanogenesis inhibitors (plant bioactive compounds and dietary lipids) were tested to determine their effect on nutrient digestibility and methane gas production in feed based on plantation waste. Experiments were carried out in vitro and in vivo on various types of ruminants. Plant bioactive compounds such as tannins are proven to reduce methane production through their ability to defaunate in the rumen. Tannins may also have direct effect on methanogens and indirectly by reducing fiber digestion. In addition, direct-fed microbial (DFM) feed additives such as Saccharomyces cerevisiae, Bacillus amyloliquifaciens, and Aspergillus oryzae can be used in ruminants to increase livestock productivity. Furthermore, virgin coconut oil as a dietary lipid contains medium-chain fatty acids, mainly lauric acid, which can inhibit the development of ciliates of protozoa and methanogenic bacteria that produce methane in the rumen.

Board Invited Review: Enteric methane mitigation interventions

Mitigation of enteric methane (CH₄) presents a feasible approach to curbing agriculture’s contribution to climate change. One intervention for reduction is dietary reformulation, which manipulates the composition of feedstuffs in ruminant diets to redirect fermentation processes toward low CH₄ emissions. Examples include reducing the relative proportion of forages to concentrates, determining the rate of digestibility and passage rate from the rumen, and dietary lipid inclusion. Feed additives present another intervention for CH₄ abatement and are classified based on their mode of action. Through inhibition of key enzymes, 3-nitrooxypropanol (3-NOP) and halogenated compounds directly target the methanogenesis pathway. Rumen environment modifiers, including nitrates, essential oils, and tannins, act on the conditions that affect methanogens and remove the accessibility of fermentation products needed for CH₄ formation. Low CH₄-emitting animals can also be directly or indirectly selected through breeding interventions, and genome-wide association studies are expected to provide efficient selection decisions. Overall, dietary reformulation and feed additive inclusion provide immediate and reversible effects, while selective breeding produces lasting, cumulative CH₄ emission reductions.

Harnessing plant bioactivity for enteric methane mitigation in Australia

This review provides examples of the utilisation of plant bioactivity to mitigate enteric methane (CH4) emissions from the Australian ruminant production systems. Potential plant-based mitigation strategies that reduce CH4 without major impacts on forage digestibility include the following: (i) low methanogenic tropical and temperate grass, legume and shrub forage species, which offer renewable and sustainable solutions and are easy to adopt, but may have restricted geographical distribution or relatively high costs of establishment and maintenance; (ii) plant-based agricultural by-products including grape marc, olive leaves and fruit, and distiller’s grains that can mitigate CH4 and provide relatively cheap high-nutrient supplements, while offsetting the impact of agricultural waste, but their use may be limited due to unfavourable characteristics such as high protein and water content or cost of transport; (iii) plant extracts, essential oils and pure compounds that are abundant in Australian flora and offer exciting opportunities on the basis of in vitro findings, but require verification in ruminant production systems. The greatest CH4 mitigation potential based on in vitro assays come from the Australian shrubs Eremophila species, Jasminum didymium and Lotus australis (>80% CH4 reduction), tropical forages Desmanthus leptophyllus, Hetropogon contortus and Leucaena leucocephala (~40% CH4 reduction), temperate forages Biserrula pelecinus (70–90% CH4 reduction), perennial ryegrass and white clover (~20% CH4 reduction), and plant extracts or essential oils from Melaleuca ericifolia, B. pelecinus and Leptospermum petersonii (up to 80% CH4 reduction). Further research is required to confirm effectiveness of these plant-based strategies in vivo, determine optimal doses, practical modes of delivery to livestock, analyse benefit–cost ratios and develop pathways to adoption.

Effect of tannins from tropical plants on methane production from ruminants: A systematic review

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A negative relationship was observed between the level of tannin inclusion and CH₄ emission.

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The effect of CH₄ mitigation is increasing as the level of tannin inclusion is higher.

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Sub-group analysis revealed differences of tannins supplementation response according to CH₄ emission measurements techniques.

Methane (CH₄) is a greenhouse gas generated during the feed fermentation processes in the rumen. However, numerous studies have been conducted to determine the capacity of plant secondary metabolites to enhance ruminal fermentation and decrease CH₄ production, especially those plants rich in tannins. This review conducted a descriptive analysis and meta-analysis of the use of tannin-rich plants in tropical regions to mitigate CH₄ production from livestock. The aim of this study was to analyse the effect of tannins supplementation in tropical plants on CH₄ production in ruminants using a meta-analytic approach and the effect on microbial population. Sources of heterogeneity were explored using a meta-regression analysis. Final database was integrated by a total of 14 trials. The ‘meta’ package in R statistical software was used to conduct the meta-analyses. The covariates defined a priori in the current meta-regression were inclusion level, species (sheep, beef cattle, dairy cattle, and cross-bred heifers) and plant. Results showed that supplementation with tropical plants with tannin contents have the greatest effects on CH₄ mitigation . A negative relationship was observed between the level of inclusion and CH₄ emission (−0.09), which means that the effect of CH₄ mitigation is increasing as the level of tannin inclusion is higher. Therefore, less CH₄ production will be obtained when supplementing tropical plants in the diet with a high dose of tannins.

Effects of Dietary Tannins’ Supplementation on Growth Performance, Rumen Fermentation, and Enteric Methane Emissions in Beef Cattle: A Meta-Analysis

The environmental sustainability of beef production is a significant concern within the food production system. Tannins (TANs) can be used to minimize the environmental impact of ruminant production because they can improve ruminal fermentation and ruminants’ lifetime performances and mitigate methane (CH4) emissions. The objective of this study was to evaluate the effects of dietary supplementation with TANs as sustainable natural alternative to reduce the environmental impact on growth performance, rumen fermentation, enteric CH4 emissions, and nitrogen (N) use efficiency of beef cattle through a meta-analysis. A comprehensive search of studies published in scientific journals that investigated the effects of TANs’ supplementation on the variables of interest was performed using the Scopus, Web of Science, and PubMed databases. The data analyzed were extracted from 32 peer-reviewed publications. The effects of TANs were assessed using random-effects statistical models to examine the standardized mean difference (SMD) between TANs’ treatments and control (non-TANs). The heterogeneity was explored by meta-regression and subgroup analysis was performed for the covariates that were significant. TANs’ supplementation did not affect weight gain, feed consumption, feed efficiency, or N use efficiency (p > 0.05). However, it reduced the concentration of ammonia nitrogen in rumen (SMD = −0.508, p < 0.001), CH4 emissions per day (SMD = −0.474, p < 0.01) and per unit dry matter intake (SMD = −0.408, p < 0.01), urinary N excretion (SMD = −0.338, p < 0.05), and dry matter digestibility (SMD = −0.589, p < 0.001). Ruminal propionate (SMD = 0.250) and butyrate (SMD = 0.198) concentrations and fecal N excretion (SMD = 0.860) improved in response to TANs’ supplementation (p < 0.05). In conclusion, it is possible to use TANs as a CH4 mitigation strategy without affecting cattle growth rate. In addition, the shift from urinary to fecal N may be beneficial for environment preservation, as urinary N induces more harmful emissions than fecal N. Therefore, the addition of tannins in the diet of beef cattle could be used as a sustainable natural alternative to reduce the environmental impact of beef production.

Research progress on the application of feed additives in ruminal methane emission reduction: a review

BACKGROUND

Ruminal methane (CH4) emissions from ruminants not only pollute the environment and exacerbate the greenhouse effect, but also cause animal energy losses and low production efficiency. Consequently, it is necessary to find ways of reducing methane emissions in ruminants. Studies have reported that feed additives such as nitrogen-containing compounds, probiotics, prebiotics, and plant extracts significantly reduce ruminant methane; however, systematic reviews of such studies are lacking. The present article summarizes research over the past five years on the effects of nitrogen-containing compounds, probiotics, probiotics, and plant extracts on methane emissions in ruminants. The paper could provide theoretical support and guide future research in animal production and global warming mitigation.

METHODS

This review uses the Web of Science database to search keywords related to ruminants and methane reduction in the past five years, and uses Sci-Hub, PubMed, etc. as auxiliary searchers. Read, filter, list, and summarize all the retrieved documents, and finally complete this article.

RESULTS

Most of the extracts can not only significantly reduce CH4 greenhouse gas emissions, but they will not cause negative effects on animal and human health either. Therefore, this article reviews the mechanisms of CH4 production in ruminants and the application and effects of N-containing compounds, probiotics, prebiotics, and plant extracts on CH4 emission reduction in ruminants based on published studies over the past 5 years.

CONCLUSION

Our review provides a theoretical basis for future research and the application of feed additives in ruminant CH4 emission reduction activities.

Methane Emissions from Ruminants in Australia: Mitigation Potential and Applicability of Mitigation Strategies

Anthropomorphic greenhouse gases are raising the temperature of the earth and threatening ecosystems. Since 1950 atmospheric carbon dioxide has increased 28%, while methane has increased 70%. Methane, over the first 20 years after release, has 80-times more warming potential as a greenhouse gas than carbon dioxide. Enteric methane from microbial fermentation of plant material by ruminants contributes 30% of methane released into the atmosphere, which is more than any other single source. Numerous strategies were reviewed to quantify their methane mitigation potential, their impact on animal productivity and their likelihood of adoption. The supplements, 3-nitrooxypropanol and the seaweed, Asparagopsis, reduced methane emissions by 40+% and 90%, respectively, with increases in animal productivity and small effects on animal health or product quality. Manipulation of the rumen microbial population can potentially provide intergenerational reduction in methane emissions, if treated animals remain isolated. Genetic selection, vaccination, grape marc, nitrate or biochar reduced methane emissions by 10% or less. Best management practices and cattle browsing legumes, Desmanthus or Leucaena species, result in small levels of methane mitigation and improved animal productivity. Feeding large amounts daily of ground wheat reduced methane emissions by around 35% in dairy cows but was not sustained over time.

Examining the Variables Leading to Apparent Incongruity between Antimethanogenic Potential of Tannins and Their Observed Effects in Ruminants—A Review

In recent years, several secondary plant metabolites have been identified that possess antimethanogenic properties. Tannin-rich forages have the potential to reduce methane emissions in ruminants while also increasing their nutrient use efficiency and promoting overall animal health. However, results have been highly inconclusive to date, with their antimethanogenic potential and effects on both animal performance and nutrition being highly variable even within a plant species. This variability is attributed to the structural characteristics of the tannins, many of which have been linked to an increased antimethanogenic potential. However, these characteristics are seldom considered in ruminant nutrition studies—often because the analytical techniques are inadequate to identify tannin structure and the focus is mostly on total tannin concentrations. Hence, in this article, we (i) review previous research that illustrate the variability of the antimethanogenic potential of forages; (ii) identify the source of inconsistencies behind these results; and (iii) discuss how these could be optimized to generate comparable and repeatable results. By adhering to this roadmap, we propose that there are clear links between plant metabolome and physiology and their antimethanogenic potential that can be established with the ultimate goal of improving the sustainable intensification of livestock.

Effect of Leucaena leucocephala and corn oil on ruminal fermentation, methane production and fatty acid profile: an in vitro study

Aims This in vitro study aimed to examine the effect of proportions of Leucaena (Leucaena leucocephala (Lam.) de Wit) to Napier grass (Pennisetum purpureum Schumach) or levels of corn oil (CO) and their interaction on ruminal fermentation, methane (CH4) production and fatty acid profile. Methods The experiment was conducted as a 4 × 3 factorial arrangement following a completely randomised design with two factors. The treatments were according to the proportion of Leucaena and Napier grass (in g/kg DM, Treatment (T)1 = 0:750 (control), T2 = 250:500, T3 = 500:250, T4 = 750:0). Three levels of CO (in mg rumen fluid, CO1 = 0, CO2 = 10, CO3 = 20 respectively) were added to each of the diet, giving a total 12 dietary treatments. Key results Replacing Napier grass with Leucaena at 500 g/kg (T3) and 750 g/kg (T4) levels increased the molar volatile fatty acid concentration, microbial protein synthesis (P &lt; 0.001) and ammonia nitrogen concentration (P = 0.003), whereas ruminal protozoa concomitantly decreased (P &lt; 0.05). The addition of CO at 10 mg also reduced the number of ruminal protozoa compared with the control (P &lt; 0.001). A significant Leucaena × CO interaction was observed on the increase of ammonia nitrogen and microbial protein synthesis, and CH4 production was simultaneously suppressed (P &lt; 0.001). There was also a significant Leucaena × CO interaction on increasing concentration of C18:1 cis-9, C18:2 cis-10 cis-12 and α-linolenic acid, which thus contributed to the increase of n-3 polyunsaturated fatty acids accumulation in the culture (P &lt; 0.001). However, the concentration of C18:0 was not influenced by the treatments (P &gt; 0.05). Conclusion This study demonstrated that the inclusion of Leucaena into a Napier grass-based diet at 500 g/kg and 750 g/kg DM positively affected rumen fermentation, reduced CH4 formation and increased beneficial fatty acids in the rumen. Although CO had similar positive effects on CH4 production and targeted beneficial fatty acids, it reduced the microbial protein synthesis at inclusion of 20 mg/mL DM. Overall, there were synergistic interactions between Leucaena and CO in reducing CH4 production and improving the fatty acid profile in the rumen. Implications It is possible to improve animal productivity while reducing the environmental impact of livestock production through inclusion of tannin-containing Leucaena and CO in ruminant diets in tropical regions where C4 grasses typically have low nutritive value.

Review: Strategies for enteric methane mitigation in cattle fed tropical forages

Methane (CH4) is a greenhouse gas (GHG) produced and released by eructation to the atmosphere in large volumes by ruminants. Enteric CH4 contributes significantly to global GHG emissions arising from animal agriculture. It has been contended that tropical grasses produce higher emissions of enteric CH4 than temperate grasses, when they are fed to ruminants. A number of experiments have been performed in respiration chambers and head-boxes to assess the enteric CH4 mitigation potential of foliage and pods of tropical plants, as well as nitrates (NO3-) and vegetable oils in practical rations for cattle. On the basis of individual determinations of enteric CH4 carried out in respiration chambers, the average CH4 yield for cattle fed low-quality tropical grasses (>70% ration DM) was 17.0 g CH4/kg DM intake. Results showed that when foliage and ground pods of tropical trees and shrubs were incorporated in cattle rations, methane yield (g CH4/kg DM intake) was decreased by 10% to 25%, depending on plant species and level of intake of the ration. Incorporation of nitrates and vegetable oils in the ration decreased enteric CH4 yield by ∼6% to ∼20%, respectively. Condensed tannins, saponins and starch contained in foliages, pods and seeds of tropical trees and shrubs, as well as nitrates and vegetable oils, can be fed to cattle to mitigate enteric CH4 emissions under smallholder conditions. Strategies for enteric CH4 mitigation in cattle grazing low-quality tropical forages can effectively increase productivity while decreasing enteric CH4 emissions in absolute terms and per unit of product (e.g. meat, milk), thus reducing the contribution of ruminants to GHG emissions and therefore to climate change.

Productive behavior in growing kid goats and methane production with the inclusion of chokecherry leaf (Prunus salicifolia)

Currently for the reduction of methane (CH4) emissions are using fodder rich in condensed tannins, however, not yet known exactly how they act in the rumen is not yet clear. The objective of this study was to evaluate the effect of the inclusion of leaves of Prunus salicifolia (PS, 0%, 15%, and 30%) on the productive behavior of growing kid goats, methane production, nutritional value, fermentation, and ruminal digestibility through an in vivo and in vitro study was performed. Diets were administered ad libitum to 6 Saanen kids with live weight (LW) of 12.25 ± 2.25 kg. Three levels of inclusion were used in a diet based on ground corn grain, soybean meal, corn stover, and oat hay in substitution with P. salicifolia leaves. The in vivo productive behavior was determined, as well as the fermentation kinetics, in vitro gas production, CH4 and hydrogen (H2) in an in vitro system was determined. For the in vivo study, we used a 3 × 3 Latin square design in in vivo study and an analysis of variance with three replications for in vitro gas production. The inclusion of 30% increased (P = 0.0011) dry matter intake (DMI 589.33 g/day) compared to the control group (418.80 g/day). The highest N excretion (feces and urine) (P < 0.001) was for T0, in addition to presenting a negative nitrogen balance compared with T15 and T30. The production of CH4 (mM)/g DM incubated, and CH4 (mM)/g DM fermented, CH4 (mM/day), and H2 was lower (P < 0.05) in T30 than T0 and T15. CH4 (mM)/day was lower (P < 0.036) in T130 (283 mM/day) compared with T0 (407 mM/day) P. salicifolia is a forage that helps to reduce the production of methane and can be included in the diets of growing kid goats in amounts less than 30% without affecting production performance.

The effects of dietary supplementation with 3-nitrooxypropanol on enteric methane emissions, rumen fermentation, and production performance in ruminants: a meta-analysis

The aim of this study was to investigate the effects of 3-nitrooxypropanol (NOP) on gas production, rumen fermentation, and animal performances depending on animal type using a meta-analysis approach. A database consisted of data from 14 studies, 18 experiments and 55 treatments. The supplementation of NOP linearly decreased methane (CH₄) emissions [g/kg dry matter intake (DMI)] regardless of animal type and length of experimental period (beef, p < 0.0001, R² = 0.797; dairy, p = 0.0003, R² = 0.916; and long term, p < 0.0001, R² = 0.910). The total volatile fatty acids (VFA) concentration and the proportion of acetate, based on beef cattle database, were significantly decreased with increasing NOP supplementation (p = 0.0015, R² = 0.804 and p = 0.0003, R² = 0.918), whereas other individual VFAs was increased. Based on the dairy database, increasing levels of NOP supplementation linearly decreased proportion of acetate (p = 0.0284, R² = 0.769) and increased that of valerate (p = 0.0340, R² = 0.522), regardless of significant change on other individual VFAs. In animal performances, the DMI, from beef cattle database, tended to decrease when the levels of NOP supplementation increased (p = 0.0574, R² = 0.170), whereas there was no significant change on DMI from dairy cattle database. The NOP supplementation tended to decrease milk yield (p = 0.0606, R² = 0.381) and increase milk fat and milk protein (p = 0.0861, R² = 0.321, p = 0.0838, R² = 0.322). NOP is a viable candidate as a feed additive because of its CH₄ mitigation effects, regardless of animal type and experiment period, without adverse effects on animal performances.

Effects of long-term diet supplementation with Gliricidia sepium foliage mixed with Enterolobium cyclocarpum pods on enteric methane, apparent digestibility, and rumen microbial population in crossbred heifers1

In the last decades, strategies have been evaluated to reduce rumen methane (CH4) production by supplementing tropical forages rich in secondary compounds; however, most of these beneficial effects need to be validated in terms of their persistence over time. The aim of this study was to assess CH4 emissions over time in heifers fed with and without Gliricidia sepium foliage (G) mixed with ground pods of Enterolobium cyclocarpum(E). Two groups of 4 crossbred (Bos taurus x Bos indicus) heifers (284 ±17 kg initial weight) were fed with 2 diets (0% and 15% of a mixture of the pods and foliage [E + G:0 and E + G:15, respectively]) over 80 d, plus 2 wk before the experiment, in which every animal was fed a legume and pod-free diet. Every 14 d, CH4 production, apparent digestibility, volatile fatty acids (VFA), and microbial population were quantified for each animal. The experiment was conducted with a repeated measurements design over time. Diets fed differed in terms of their crude protein (CP), condensed tannins, and saponins content supplied by E. cyclocarpum and G. sepium. For most of the experiment, dry matter intake (DMI) and digestible dry-matter intake (DDMI) were 6.3 kg DMI/d and 512 g DDMI/kg, respectively, for both diets (diet: P > 0.05). Apparent digestible crude protein (DCP) was reduced by 21 g DCP/kg DM when the diet was supplemented with E + G:15 (P = 0.040). Molar proportions of VFA's in the rumen did not differ between diets or in time (P > 0.05). Daily methane production, expressed in relation to DMI, was 23.95 vs. 23.32 g CH4/kg DMI for the diet E + G:0 and E + G:15, respectively (diet: P = 0.016; Time: P > 0.05). Percent gross energy loss as CH4 (Ym) with grass-only diets was above 8.1%, whereas when feeding heifers with the alternate supplementation, Ym values of 7.59% (P = 0.016) were observed. The relative abundance of total bacterial, protozoa, and methanogenic archaeal replicates was not affected by time nor by the incorporation of legume and pods into the diet (P > 0.05). Results suggest that addition of G. sepium mixed with E. cyclocarpum pods can reduce CH4 production in heifers and this response remains over time, without effect on microbial population and VFA concentration and a slight reduction in CPD digestibility.