Methane Gas Production Research Articles

Nutrient Composition and Metabolic Energy of Different Fruit Tree Leaves as Feeding Sources for Ruminants

The need for roughage in the animal nutrition industry has led to the search for various alternative roughage. In this context, as a result of the research, tree leaves have the potential to be considered as a nutritious and balanced forage source for animals. In this study, it was aimed to investigate the usability of apple (Malus domestica), apricot (Prunus armeniaca), cherry (Prunus avium), grape (Vitis vinifera), and umber mulberry (Morus rubra) leaves in ruminant nutrition. As a result of the research, nutritional contents of tree leaves (dry matter, crude protein, crude ash, crude oil, neutral detergent fiber, acid detergent fiber, acid detergent lignin, tannin), in vitro gas, carbon dioxide and methane gas production, in vitro gas post-production rumen fluid volatile fatty acid contents were found to be different from each other (P

Nutrient digestibility, characteristics of rumen fermentation, and microbial protein synthesis from Pesisir cattle diet containing non-fiber carbohydrate to rumen degradable protein ratio and sulfur supplement.

To achieve optimal feed efficiency in ruminants, especially Pesisir cattle, it is necessary to maintain a harmonious equilibrium between energy and protein levels within the rumen. Sulfur supplementation can potentially escalate the energy-protein balance in the rumen. The aim of this study was to explore the formulation of ruminant diets by synchronizing rumen degradable protein (RDP) and non-fiber carbohydrate (NFC) while adding sulfur minerals at different levels. Nutrient digestibility, NH3 concentration, volatile fatty acids (VFA) production, microbial protein synthesis (MPS), and methane gas production were assessed. We employed a randomized block design with a 2 × 2 × 3 factorial arrangement and examined diverse incubation periods of 6, 24, and 48 h. Treatment consisted of RDP (60% and 65%), NFC (35% and 40%), and sulfur (0%, 0.15%, and 0.3%) levels. In this study, the Tilley and Terry in vitro technique, which used Pesisir cattle's rumen fluid, was employed to assess the digestibility of dry matter, organic matter, acid detergent fiber, neutral detergent fiber, and RDP-Rumen undegradable protein. In addition, it measures various rumen fluid attributes, including pH, NH3, VFA, MPS, and methane gas production. Treatment with a coordinated combination of 65% RDP and 40% NFC combined with 0.15% sulfur supplement yielded significantly improved digestibility and notably reduced methane gas production (p < 0.05). The enhancement in digestibility and reduction in methane gas emissions can be attributed to the interaction of RDP, NFC, and sulfur. Feed digestibility was increased in the 65% RDP treatment with 40% NFC and 0.15% sulfur, along with a decrease in methane gas production.

The governance of Household Hazardous Waste (HHW): A literature review of HHW-related regulation in Southeast Asian developing countries

Growing cities of developing countries followed by human activities brings challenge on how to manage the massive solid waste production. Pile of solid waste in the collecting or dumping sites produce methane gas that threaten earths’ climate change, whereas leachate with organic, inorganic, and hazardous contaminants resulted in soil and groundwater pollution. Furthermore, untreated solid wastes are aesthetically disturbing and environmentally polluting as they enter the water bodies. More than 40% of the Municipal Solid Waste are generated by household activities and approximately 1% of it contains hazardous materials, such as heavy metals and inert materials. Unprocessed Household Hazardous Waste (HHW) carries substantial ecological impacts. However, issues on HHW considered to have less attention either by community or government due to the requirement of specific treatment and the cost of final disposal. The role of regulation or guidelines are critical to manage the HHW handling. This review aims to explore the availability of national as well as local regulation related to HHW management in Southeast Asian developing countries and to analyze the correlation between GNI level and the government concern on HHW issues. Despite the main solution, the availability of HHW regulation is required to govern the management and minimize the contamination to the environment. The analysis is based on literature from journals as well as official websites from each country which studied. The result of the study can give an alternate perspective on the governance of HHW in developing countries.

Methane Production from Poly(lactic Acid) (PLA) and Polyhydroxybutyrate (PHB) Biodegradable Plastics with Anaerobic Granulated Sludge

- In this study, using Methanosarcina barkeri DSM 800 and Methanococcus vannielii DSM 1224 methanogenic bacteria under mesophilic (38 ± 1oC) and thermophilic (58 ± 1oC) conditions in anaerobic granulated sludge taken from Pakmaya Yeast Factory in Izmir, Turkey; Methane production from biodegradable plastics with poly(lactic acid) (PLA) and polyhydroxybutyrate (PHB) was investigated. Effect of different operating parameters, increasing biodegradation times (from 10 days to 500 days), different inoculumsubstrate ratios (ISRs) (16, 8, 4, 2, 1) and increasing biochemical methane potential (BMP) times (between 10 day and 500 days) for the production of methane gas from PLA and PHB biodegradable plastics in anaerobic granular sludge waste; Methanosarcina barkeri DSM 800 and Methanococcus vannielii DSM 1224 methanogenic bacteria were operated during the anaerobic digestion process under anaerobic conditions at mesophilic (38 ± 1oC) and thermophilic (58 ± 1oC) experimental temperatures. PLA biodegradable plastics were operated at optimum pH=7.6. PHB biodegradable plastics were carried out at optimum pH=8.1. Predicting the biodegradation behavior of PLA and PHB biodegradable plastics with BMP tests; It is found that the ISR parameter plays a very important role. This study showed that temperature plays a key role in the aging of microorganisms (Methanosarcina barkeri DSM 800 and Methanococcus vannielii DSM 1224 methanogenic bacteria) during anaerobic digestion, the degradation of bioplastic materials (PLA and PHB) and the degradation of their natural properties. The increase in temperature from mesophilic conditions to thermophilic conditions increased the activities of methanogenic bacteria such as Methanosarcina barkeri DSM 800 and Methanococcus vannielii DSM 1224. The maximum cumulative CH4(g) production was measured at 630 NL CH4 / kgVS for PHB biodegradable plastics in anaerobic granulated sludge with inoculum culture (the mixture of Methanosarcina barkeri DSM 800 and Methanococcus vannielii DSM 1224 methanogenic bacteria), at ISR=16 value, after 100 days, at pH=8.1 and at 58±1oC, respectively. The maximum 97% biodegradation efficiency was observed for PHB biodegradable plastics after 100 days, at pH=8.1 and at 58 ± 1oC thermophilic conditions, respectively.

Analysis of landfill leachate promoting efficient application of weathered coal anaerobic fermentation

This research aimed to develop a new method for clean utilization and treatment of landfill leachate and solid waste weathered coal. Landfill leachate and weathered coal were adopted for combined anaerobic fermentation for methane production. The characteristics of microbial community, mechanism of biological methane production, and utilization characteristics of fermentation broth and solid residue for co-fermentation were analyzed through metagenomics, soluble organic matter detection and thermogravimetric (TG) analysis. The obtained results revealed that combined anaerobic fermentation increased methane production by 80.1%. Syntrophomonas, Salipiger, Methanosaeta and Methanothrix were highly correlated. Gene abundances of 2-oxoacid ferredoxin oxidoreductase and enolase were increased in methane conversion pathway mainly by acetic acid. Pyruvate-ferroredoxin oxidoreductase, 2-oxoglutarate synthase and succinate dehydrogenase acetate synthase intensified electron transfer pathways among microorganisms. Fulvic acid, tyrosine and tryptophan contents were high in fermentation broth. Volatile decomposition temperature, ignition point and residual char combustion temperature of residual coal were decreased and combustion was more stable. The obtained results showed that the co-fermentation of landfill leachate and weathered coal improved biological methane gas production, degraded weathered coal and improved combustion performance, which provided a new idea for weathered coal clean utilization.

Use of irradiated chitosan as a matrix for slow-release urea and in vitro fermentation characteristics of slow-release urea supplementation in ruminant rations

Background and Aim: Irradiated chitosan can be used as a matrix for slow-release urea (SRU) production. This study aimed to (1) determine the optimal formulation of irradiated chitosan matrix for controlling nitrogen release and (2) evaluate the characteristics of SRU in vitro fermentation based on irradiated chitosan as a feed supplement. Materials and Methods: In the first phase of the investigation, four chitosan-based SRU formulations with varying amounts of acrylamide (3 and 5 g) and gamma irradiation (5 and 10 kGy) were evaluated. Scanning electron microscopy, Fourier transform mid-infrared spectroscopy, and ammonia release characteristics were used to observe morphological, functional group, and ammonia release characteristics. In the second phase of research, the most effective SRU formulation was utilized as a supplement to ruminant rations based on rice straw, sorghum straw, and alfalfa. Gas production, rumen fermentation characteristics, and methane gas production were observed in vitro. Results: On the basis of surface image analysis, the four SRU formulas generate a similar appearance. Compared with untreated urea, the SRU3 formula reduced the percentage of ammonia emission by 12.85%–27.64% after 24 h of incubation (p = 0.05), as determined by the first phase study. SRU3 became the basis for the second testing phase. The addition of SRU3 did not affect the optimal gas production in vitro. SRU3 treatment produced less gas than Optigen® treatment (p = 0.05). With regard to rumen fermentation and digestibility, Optigen® yielded better results than SRU3 (p = 0.05). However, the treatment with SRU3 resulted in reduced methane production compared to that in the control (p = 0.05). Conclusion: Irradiated chitosan as an SRU matrix may control the release of ammonia in the rumen medium. The SRU3 formulation is the most effective. The addition of SRU to rice straw-based rations reduces methane production without affecting in vitro digestibility. Keywords: fermentation characteristics, irradiated chitosan, ruminant, slow-release urea.

PYROLYSIS OF CORN COB BIOMASS TOWARD GASEOUS PRODUCTS ON SMALL CAPACITY REACTOR

Corn waste is the result of agricultural production that can be further utilized and get additional economic for the community. Waste Corn cab is one of Indonesia abundant biomass apart from. The utilization of biomass by implementing pyrolysis process can be viable solution. This study aims to observe the determination corn cab pyrolysis using HCL-bentonite activation and without bentonite towards syngas product (CH4-H2-CO-CO2). Updraft reactor was utilized for 30 minutes pyrolysis process. We used MQ4, MQ8, MQ7 coupled with Arduino UNO for measuring CH4, H2, CO2 and CO in ppm unit. Compared without bentonite, the result showed that methane (CH4) gas production increased. In addition, we found also that hydrogen (H2) gas increased respectively. Not mention, the content of CO increased.

Full quantitative resource utilization of raw mustard waste through integrating a comprehensive approach for producing hydrogen and soil amendments

BackgroundPickled mustard, the largest cultivated vegetable in China, generates substantial waste annually, leading to significant environmental pollution due to challenges in timely disposal, leading to decomposition and sewage issues. Consequently, the imperative to address this concern centers on the reduction and comprehensive resource utilization of raw mustard waste (RMW). To achieve complete and quantitative resource utilization of RMW, this study employs novel technology integration for optimizing its higher-value applications.ResultsInitially, subcritical hydrothermal technology was applied for rapid decomposition, with subsequent ammonia nitrogen removal via zeolite. Thereafter, photosynthetic bacteria, Rhodopseudomonas palustris, were employed to maximize hydrogen and methane gas production using various fermentation enhancement agents. Subsequent solid-liquid separation yielded liquid fertilizer from the fermented liquid and soil amendment from solid fermentation remnants. Results indicate that the highest glucose yield (29.6 ± 0.14) was achieved at 165–173℃, with a total sugar content of 50.2 g/L and 64% glucose proportion. Optimal ammonia nitrogen removal occurred with 8 g/L zeolite and strain stable growth at 32℃, with the highest OD600 reaching 2.7. Several fermentation promoters, including FeSO4, Neutral red, Na2S, flavin mononucleotide, Nickel titanate, Nickel oxide, and Mixture C, were evaluated for hydrogen production. Notably, Mixture C resulted in the maximum hydrogen production (756 mL), a production rate of 14 mL/h, and a 5-day stable hydrogen production period. Composting experiments enhanced humic acid content and organic matter (OM) by 17% and 15%, respectively.ConclusionsThis innovative technology not only expedites RMW treatment and hydrogen yield but also substantially enriches soil fertility. Consequently, it offers a novel approach for low-carbon, zero-pollution RMW management. The study’s double outcomes extend to large-scale RMW treatment based on the aim of full quantitative resource utilization of RMW. Our method provides a valuable reference for waste management in similar perishable vegetable plantations.

Investigation of Boron Addition to Dried Alfalfa In Vitro Ruminal Profile and Potential for Reducing Enteric Methane Emission

The aim of our study is to investigate the effects of increasing doses of boron on methane gas production amounts, short chain fatty acids level, protozoa number and organic matter digestibility in vitro with HFT (Hohenheim Futterwert Test) technique. In vitro incubation was performed in the Hohenheim Gas test method at 39°C for 24 hours in the study. Dried alfalfa was used as substrate for fermentation. Increasing doses of boron were used on fresh rumen fluid, buffer solution and dried alfalfa. In the study, 54 syringes were used for a total of 6 groups, including 1 control and 5 trial ( B1: 25 ppm boric acid, B2: 50 ppm boric acid, B3: 100 ppm boric acid, B4: 200 ppm boric acid, B4: 500 ppm boric acid). The measurement of methane gas at 2, 4, 6, 8, 12 and 24th hours of boric acid addition at increasing doses was found to be significant the difference between the groups at each hour under in vitro rumen conditions. When we look at the effect of the dose; Increasing doses appear to reduce methane production for each measured hour. The difference between the measured hours (except the 24th hour) of each group was not significant. However, the difference between the groups was found to be significant in the methane measurement made only for the 24th hour. At the 24th hour of fermentation under in vitro rumen condition, acetic acid and total short chain fatty acid values were linearly and cubically affected. With increasing doses of boron, propionic acid, isobutyric acid, butyric acid and valeric acid values were linearly affected The total number of protozoa was not affected by the addition of increasing doses of boron at the 24th hour of fermentation under in vitro rumen conditions. Consequently, the addition of boric acid at increasing doses in in vitro rumen conditions decreased methane production and positively affected the amount of some short-chain fatty acids, organic matter digestibility and total short chain fatty acids. In the light of these findings, it was emphasized that boron has the potential to reduce methane emissions from ruminant animals, considering the greenhouse gas effect.

Thermo-Hydro-Mechanic-Chemical coupling model for hydrate-bearing sediment within a unified granular thermodynamic theory

The extraction process of methane hydrate involves interactions of multiple fields, phases, and loading stages. By extrapolating deductions from the thermodynamic equation in granular thermodynamic framework and amalgamating with coupled flow theory and linear non-equilibrium theory, a comprehensive Thermo-Hydro-Mechanic-Chemical (THMC) coupling model for hydrate-bearing sediment is established in this study. The mechanical field is established by energy dissipation conservation, the hydraulic field considers the increase in gas and liquid permeability due to temperature gradients, while the thermal field incorporates the rates of seepage, hydrate dissociation, and volumetric strain. Meanwhile, Darcy's law is explained as general deductions from the thermodynamic equation without the need for assumption. The proposed model is applied from the perspective of unit scale and coupling field, and verified with the test data. The modelling results show that the deduced model can capture the strain-softening, dilatancy, and stress paths behavior under various drainage conditions, and the volumetric strain, methane gas production and variations in heat exchange caused by the hydrate dissociation can also be predicted. Furthermore, the mechanical response and dissociation properties of sediment samples with various parameter values are discussed.

The Balance of Rumen Degradable Protein with Non-Fiber Carbohydrate in Cattle Rations and its Effect on Total Gas Production, Gas Kinetics and Methane Gas Production

The Balance of Rumen Degradable Protein with Non-Fiber Carbohydrate in Cattle Rations and its Effect on Total Gas Production, Gas Kinetics and Methane Gas Production

Enhancing physicochemical, rheological properties, and in vitro rumen fermentation of starch with Melastoma candidum D. Don fruit extract.

The utilization of polyphenol-modified starch in ruminants has not undergone extensive exploration. This study aimed to investigate the impact of the complex formed between starch and Melastoma candidum D. Don fruit extract on physicochemical properties, phenol release kinetics in various buffers simulating the gastrointestinal tract, methane production, and post-rumen digestibility. The interaction between starch and M. candidum D. Don fruit extract significantly (p < 0.001) increased resistant starch and particle size diameter. The maximum phenolic release from complex between starch and M. candidum D. Don fruit extract, due to gastrointestinal tract-simulated buffers, ranged from 22.96 to 34.60 mg/100 mg tannic acid equivalent. However, rumen and abomasum-simulated buffers released more phenolic content, whereas the intestine-simulated buffer showed higher antioxidant activity (ferric ion-reducing antioxidant power). Furthermore, complex between starch and M. candidum D. Don fruit extract significantly decreased dry matter rumen digestibility (p < 0.001) and maximum methane gas production (p < 0.001).

NUTRIENT COMPOSITION, IN VITRO GAS AND METHANE PRODUCTION OF Pleurotus SPECIES TREATED CROP RESIDUES FOR THEIR USE IN RUMINANT DIETS

A promising approach for the provision of high-quality supplementary feed for dry season ruminant feeding is the use of fungal-treated crop residues. This current study, therefore, used 3 Pleurotus species (P. ostreatus -PO, P. florida – PF, and P. sajor-caju- PS) to treat 4 crop residues (cowpea chaff - CC, millet chaff - MC, groundnut haulm - GH, and maize stover -MST) over 20 days at room temperature. The treated residues were afterward dried and sub-samples were taken for chemical composition (Dry matter – DM, crude protein – CP, Neutral detergent fibre – NDF, and Acid detergent fibre – ADF) determination and in vitro studies (in vitro gas and methane gas production). The Pleurotus species improved the crop residues nutrient composition through increased CP values and decreased NDF and ADF values but the species varied in their residues preference. PO greatly improved GH and CC; PS greatly improved MC; and PF greatly improved MST. The Pleurotus species improved the in vitro gas production of millet chaff (57 – 107 ml/ g DM – PF; 123 ml/ g DM – PS; and 130 ml/ g DM – PO) only. The highest in vitro gas production in PO-treated MC was complemented with comparable methane gas production (3.28 – 5.19 ml/ g DM) and percentage methane in total gas production (7 – 7%) to intact residue at 72h of incubation. It can be concluded that PO-treated millet chaff can be used as improved supplementary dry season feed for better ruminant production.

Heat and Mass Limitations in an Anaerobic Digestion Process

In this study, heat and mass limitations in an anaerobic reactor containing domestic solids were researched in batch reactors. The dynamic and static anaerobic data for 365 days showed that the methane production for the dynamic digestion reactor was measured as 176.86 m3 which is extremely high for static anaerobic one (102.78 m3). As the heat transfer data increased with elevated temperature the methane productions also were highlighted. The external mass transfer was observed for easily degradable solids. In the calculation of external mass transfer during the degradation of organics dissolved with difficulty some semiempirical regressions were used. In the calculation of internal mass transfer the microorganisms in the solids were taken into consideration and the diffusion was defined with Fick's law. The diffusion coefficient D, was found to be constant. Generally, the diffusion coefficient of solids in water (Dw) was &lt; 1.0. The effect of the total solid (TS) concentration in anaerobic batch reactors (TS between 12% and 39%) was investigated. The methane gas production decreased minorly when the TS levels elevated to 30%. At a TS percentage of 39%, the methane generation decreased significantly. At high TS, the mass transfer was inhibited and ended with lowered methane generations while the hydrolysis process did not affect significantly at high TS concentrations.

PENILAIAN KAPASITAS DAN PEMANFAATAN GAS METANA DI TPA BAGENDUNG CILEGON, INDONESIA

Cilegon only relies on one final disposal site, namely the Bagendung Landfill, which annually receives up to 24.742,80 tons of waste from the population of Cilegon. This amount has an impact on the amount of waste generated and affects the length of time Bagendung Landfill can operate. The process of degradation of organic waste material at the landfill produces landfill gas which includes methane gas (CH4) and carbon dioxide gas (CO2) thereby contributing to GHG (Green House Gas) emissions. This study aims to analyze the remaining operation time frame of and the production of methane gas produced from the waste disposal process at Bagendung Landfill, also its contribution to GHG emissions. This research was started by surveying to find out the waste generation that goes to the landfill and the remaining land area to receive municipal waste. This study used LandGEM version 3.02 software to calculate methane gas production resulting from the landfill waste degradation process. Due to the predicted waste collected in 2024 reaching 281,984.90 m3, Bagendung Landfill can only be utilized until 2024. The emission impact can be reduced by utilizing 1.527.184,57 m3 of methane gas to produce 1.65 GWh as an alternative to electrical energy which is very helpful in meeting the electricity needs of Cilegon City. This research indicates that Bagendung Landfill will not be able to maintain its capacity as it will be reached one year earlier than designed. Utilizing landfill methane gas increases the environment's quality by avoiding 25.471,47 tCO2eq of GHG emissions. Moreover, it can continue after the landfill is closed.&#x0D; Keywords: landfill; waste generation; methane gas production; emission

Agricultural waste in Libya as a resource for biochar and methane production: An analytical study

This study aims to analyse the possibility of exploiting agricultural waste in Libya to produce biochar and methane gas, and to evaluate the technical, economic and environmental aspects associated with this technology. In this study, the focus was on seven agricultural projects located in the Libyan desert, where these projects contain many varieties of Crops. A region with a total area of 5.36×106 ha was explored from Benghazi to Dernah eastward including the Green Mountain (Libya). For literary analysis, peer-reviewed scientific publications for 2018-2023 were selected from reliable bibliometric databases Scopus, Google Scholar, ScienceDirect, PubMed, since these databases have the greatest coverage of peer-reviewed publications. To study the biomass potential of the region, the Bioenergy Tool developed by IRENA was used. The study showed that agricultural residues available in Libya can be used Libya, such as grain straw, palm trees, and others, in the production of biochar and methane gas, using pyrolysis techniques to convert agricultural waste into biochar and methane gas. The study indicates that this technology can be cost-effective and environmentally effective, and that many environmental and economic benefits can be achieved, such as improving air quality, increasing agricultural land productivity, and providing new job opportunities.

Essential oils as modifiers of rumen metabolism and reducers of methane gas production

The demand for food in response to the increasing human population has challenged livestock farmers to increase food production. In this process, environmental health has been affected, not only by anthropogenic activities, but also by increasing populations of production animals. Various human activities and natural processes, such as rumen fermentation, produce methane and carbon dioxide, two gases that produce the greenhouse effect. The interest in mitigating the production of these gases has led to research that can assess the most effective measures to do so without affecting animal production. Among them, the use of certain essential oils has shown good results, not only for reducing the population of methanogenic bacteria, but also for modifying rumen metabolism to make it more efficient while reducing methane production. The literature has stated that there is still much to be researched, mainly in vivo studies, and concerning the duration of the effects achieved, to ensure that efforts to reduce methane production do not affect feed conversion..

Study of the Effect of Adding Eco-Enzyme to the Process of Decomposing Organic Waste on the Quality of Compost, Leachate, and Methane Gas Production

Waste generation is increasing along with the increase in population and human living needs. The most dominant waste composition in Indonesia is organic waste, which accounts for 53.97% of the total waste. Eco-enzyme is one of the waste utilization products that has the potential to become an activator for the decomposition process and reduce the environmental effects of waste decomposition. The aim of this research is to analyse the micronutrient content of compost, reduce leachate toxicity, and accelerate the production of methane gas resulting from decomposition using eco-enzymes. The method used was an experimental method (trial) to obtain primary data from laboratory test results during 28 days of research. The research results show that, in general, there is a significant difference in the quality of compost in organic waste that uses eco-enzyme compared to that that does not use eco-enzyme. The results of measuring the quality of the leachate resulting from decomposition show that the quality of the leachate that uses eco-enzyme is better and has lower toxicity than without using eco-enzyme (control). In the production of methane gas, the results show that methane gas production in decomposition using eco-enzymes reaches the methanogenesis process more quickly.

PSIII-22 Substituting Palm Oil By Polyunsaturated Fatty Acid Rich Oils Reduces Methane Emissions at a Different Degree Depending on Concentrate Formula of Dairy Beef Calves: in Vitro Screening

Abstract In dairy beef calves fed high-concentrate diets even methane emissions may be lesser than calves fed high-roughage diets there is still room to improvement. Substituting palm oil, an ingredient that is questioned by the impact on deforestation of some regions, by polyunsaturated fatty acids (PUFA) may be a good strategy that needs to be tested. Therefore, the aim of this study was to evaluate the rumen in vitro methane gas production by substituting palm oil by different oils rich in polyunsaturated fatty acids in two different concentrates in T1 the main protein source was SBM (8%) and in T2 the main protein source was corn DDG (15%); the remaining concentrate ingredients were 50% corn, 15 to 13% barley, 15 to 16% wheat middlings, beet pulp (5.5% in T1), 1.8% calcium carbonate, 0.5% salt, 0.2% premix. Palm oil was substituted (4 or 3.5 % in T1 or T2, respectively) by canola oil (CO), sunflower oil (SU) or soybean meal oil (SO), so 8 treatments were tested (T1, T1-CO, T1-SU, T1-SO, T2, T2-CO, T2-SU, T2-SO), which are rich in polyunsaturated fatty acids in two. Samples were 1-mm grinded at 1-mm and used in an in vitro digestibility assay as described by [Goeser and Combs (2009)]. The rumen liquid, obtained from rumens at slaughterhouse of beef animals fed high-concentrate diets with a close formula to T1 and T2, was strained through a cheesecloth, collected into pre-warmed thermal flasks, and kept at 39ºC until being used. Two incubation sets were done in parallel and in triplicate: one lasted 48 hours to calculate the DM digestibility; the second lasted 12 days to monitor the methane gas production. A tendency (P = 0.10) in the interaction among basal diet and oil source was observed in total methane production corrected by blank methane production; numerically the same trend (P = 0.14) was observed in net volume of CH4 per degraded DM. After 12 days, the least methane production values were observed in T1-SO and T2-CO (30 and 29 mL ± 4.6, respectively), while the largest methane values were observed in T1-SU (45 ± 4.6 mL) being the remaining treatments intermediate values (42, 39, 31, 38, 41 ± 4.6 mL for T1, T1-CO, T2, T2-SU, T2-SO, respectively). In conclusion, depending on the concentrate formula (protein source used) the effect of fat source used to substitute palm oil and reduce methane emission may differ.

Ruminal volatile fatty acid concentration and methane gas production in sheep (Ovis aries) fed two types of basal diets with of without Gliricidia sepium legume forage supplementation

The aim of this study was to clarify whether the type of forage diets, Napier grass (Pennisetum purpureum) vs. urea-treated rice straw, and supplementation with Gliricidia sepium affect rumen VFA production and methane emission as well as intake and digestibility in ruminants. The experiment was set up in a randomized complete block design (RCBD) composed of four treatments namely: Napier grass (T1), Napier + legume forage (T2), urea-treated rice straw (T3), and urea-treated rice straw + legume forage (T4). Each treatment was divided into four blocks (n=16) based on body weight and sex combination. The daily dry matter intake tended to increase from treatments supplemented with G. sepium (T2 and T4) compared to treatment-fed pure basal diet alone (T1 and T3). Intake relative to metabolic weight (BW 0.75) is high in T2 and T4. The molar concentration of volatile fatty acid was higher in T1, which was found comparable with T2 and T3, while T4 has the lowest. The molar proportion of acetate tended to increase in T1 and T3, while the propionate concentration was significantly high in T2 and T4 leading to lesser CH4/CO2 production respectively. These results confirmed the potential of G. sepium as a methane-mitigating supplement to basal diets such as Napier and urea-treated rice straw as feed to ruminants.