scholarly journals Measuring Livestock CH4 Emissions with the Laser Methane Detector: A Review

Methane ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 38-57
Author(s):  
Diana Sorg

The handheld, portable laser methane detector (LMD) was developed to detect gas leaks in industry from a safe distance. Since 2009, it has also been used to measure the methane (CH4) concentration in the breath of cattle, sheep, and goats to quantify their CH4 emissions. As there is no consensus on a uniform measurement and data-analysis protocol with the LMD, this article discusses important aspects of the measurement, the data analysis, and the applications of the LMD based on the literature. These aspects, such as the distance to the animal or the activity of the animals, should be fixed for all measurements of an experiment, and if this is not possible, they should at least be documented and considered as fixed effects in the statistical analysis. Important steps in data processing are thorough quality control and reduction in records to a single point measurement or “phenotype” for later analysis. The LMD can be used to rank animals according to their CH4 breath concentration and to compare average CH4 production at the group level. This makes it suitable for genetic and nutritional studies and for characterising different breeds and husbandry systems. The limitations are the lower accuracy compared to other methods, as only CH4 concentration and not flux can be measured, and the high amount of work required for the measurement. However, due to its flexibility and non-invasiveness, the LMD can be an alternative in environments where other methods are not suitable or a complement to other methods. It would improve the applicability of the LMD method if there were a common protocol for measurement and data analysis developed jointly by a group of researchers.

Agriculture ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 130 ◽  
Author(s):  
Yonas Berhanu ◽  
Lars Olav ◽  
Ajebu Nurfeta ◽  
Ayana Angassa ◽  
Jens B. Aune

This paper assesses the ability of fodder plants to reduce methane (CH4) emissions while simultaneously improving animal productivity in Ethiopia. Enteric CH4 emissions from ruminants in Ethiopia increased by 12% or ≈ 6197 Gg CO2-eq. in 2017 compared to the year 2011. In this study, six tropical multipurpose forages (Leucaena leucocephala (Lam.) de Wit, Moringa stenopetala (Bak.f.) Cuf., Sesbania sesban (L.) Merr., Cajanus cajan (L.) Millsp., Crotalaria juncea L., and Lablab purpureus L.(Sweet)) and maize stover were characterized in terms of chemical composition, in vitro CH4 production, and CH4 concentration (%). The objective was to identify forages with low CH4 production potential but with adequate forage quality. The forages differed significantly in chemical composition and in enteric CH4 emission. The dry matter (DM), ash, crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), and acid detergent lignin (ADL) ranged between 89.4–95.4%, 6.08–12.5%, 3.3–30.7%, 20.4–76.0%, 10.8–44.8, and 2.9–14.1%, respectively. All forage plants, except maize stover, contained high CP content above a threshold value (i.e., 7%). Cajanus c. generates the lowest amount of CH4 (32.83 mL/0.2 g DM incubated). CH4 concentration (%) was used as a potential indicator to determine the capacity of a plant to lower CH4 production. Among the studied species, L. purpureus showed the highest CH4 reduction potential (16%) followed by C. juncea (23.45%), M. stenopetala (24.2%), and L. leucocephala (25.5%). Moringa s. was the most frequently preferred by the farmers followed by C. juncea and L. leucocephala. We concluded that M. stenopetala, C. juncea, and L. leucocephala can be promoted as valuable feed resources for ruminants while simultaneously reducing CH4 emissions.


2008 ◽  
Vol 48 (2) ◽  
pp. 124 ◽  
Author(s):  
J. B. Vlaming ◽  
N. Lopez-Villalobos ◽  
I. M. Brookes ◽  
S. O. Hoskin ◽  
H. Clark

Several studies on methane (CH4) emissions have focussed on selecting high and low CH4-emitting animals. One challenge faced by this work is the lack of consistency, or repeatability, in animal rankings over time. Repeatability for individual animals over time needs to be high to reliably detect high and low CH4-emitting animals. A possible explanation for the lack of repeatability is a relatively high within-animal variation in daily CH4 emissions, meaning that animals could then change their ranking when compared at different points in time. An experiment was undertaken with four non-lactating dairy cattle to assess the within- and between-animal variation in CH4 emissions over time when measured using the sulfur hexafluoride (SF6) tracer technique. Two contrasting diets were fed to the cattle at maintenance energy levels: lucerne silage (diet 1) and a cereal + lucerne + straw mixed ration diet (diet 2). Daily CH4 measurements were undertaken for 23 days on diet 1 and 30 days on diet 2. There was a significant (P < 0.001) difference between diet 1 and diet 2 in daily CH4 production, with mean (±s.e.) production of 124.3 (11.1) g CH4/day from diet 1 and 169.8 (±11.0) g CH4/day from diet 2. Lower CH4 yield (g CH4/kg dry matter intake) was recorded on diet 1 (22.8 ± 2.0) than diet 2 (32.0 ± 2.0). Cows differed significantly (P < 0.05) from one another in daily CH4 yield (diet 1: cow 1 = 19.4 ± 0.6, cow 2 = 22.2 ± 0.8, cow 3 = 23.2 ± 0.7, cow 4 = 25.4 ± 0.6; diet 2: cow 1 = 26.0 ± 0.7, cow 2 = 36.4 ± 0.7, cow 3 = 29.3 ± 0.7, cow 4 = 36.6 ± 0.7). Variances for daily CH4 yield were smaller for diet 1 (within animal = 6.91, between animals = 6.23) than for diet 2 (within animal = 10.09, between animals = 27.79). Estimates of repeatability (variation between animals/total variation) for daily CH4 yield were 47 and 73% in diet 1 and 2, respectively. Coefficients of variation in average daily CH4 emissions in this experiment ranged from 8 to 18% despite the fact that each animal received the same quantity and quality of feed each day. While further research is required, the high within-animal variability in CH4 emissions measured using the SF6 tracer technique may explain why there has been difficulty in obtaining consistent rankings in CH4 yields when animals are measured on multiple occasions. The results also suggest that the SF6 tracer technique may exaggerate apparent between animal differences in CH4 emissions.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 166-167
Author(s):  
Andrea M Osorio ◽  
Kaue T Tonelli Nardi ◽  
Igor Gomes Fávero ◽  
Kaliu G Scaranto Silva ◽  
Kymberly D Coello ◽  
...  

Abstract The effects of a nutritional packet were evaluated on CH4 emissions and apparent total tract nutrient digestibility of feedlot beef steers. Thirty Angus-crossbred steers (BW = 542 ± 8.4 kg) were used in a randomized complete block design and allocated into pens equipped with SmartFeed (C-Lock; 15 steers/treatment). Steers were consuming a steam-flaked corn-based diet (88% concentrate DM basis) ad libitum for the last 65 d on feed, and received the following treatments: 1) control and 2) a nutritional packet [0.29% DM basis; live yeast (Saccharomyces cerevisiae; 8.7 Log CFU/g); Vitamin C (5.4 g/kg); Vitamin B1 (13.33 g/kg); NaCl (80 g/kg); KCl (80 g/kg)]. Methane emissions and apparent total tract nutrient digestibility were measured during 3 periods with 5-d of collections each. Gas emissions from steers were measured utilizing the SF6 tracer technique. Feed and fecal samples were collected once and twice (0700 h and 1600 h) daily, respectively, to determine digestibility of nutrients using iNDF as an internal marker. Steer was considered the experimental unit. Data were analyzed as repeated measures using the MIXED procedure of SAS with the fixed effects of treatment, period, and their interaction, and the random effect of block. No treatment × period interactions (P ≥ 0.125) were observed for DMI and any of the CH4 production variables (g/day, g/kg BW0.75, g/nutrient intake, and g/nutrient digested). Moreover, treatments did not affect digestibility of DM, OM, or ADF (P ≥ 0.300); however, digestibility of NDF was increased for treated cattle (P = 0.013), which resulted in a tendency (P = 0.098) to decrease CH4 production in g per kg NDF intake and decreased (P = 0.020) grams CH4 per kg NDF digested. The nutritional packet may be altering ruminal fermentation on intensively managed steers and improving fiber digestibility, which can have benefits on CH4 emission intensity.


2019 ◽  
Vol 3 (4) ◽  
pp. 1383-1388 ◽  
Author(s):  
Breanna M Roque ◽  
Henk J Van Lingen ◽  
Hilde Vrancken ◽  
Ermias Kebreab

Abstract: Enteric methane (CH4) production is the main source of greenhouse gas emissions from livestock globally with beef cattle contributing 5.95% of total global greenhouse gas emissions. Various mitigation strategies have been developed to reduce enteric emissions with limited success. In vitro studies have shown a reduction in CH4 emissions when using garlic and citrus extracts. However, there is paucity of data regarding in vivo studies investigating the effect of garlic and citrus extracts in cattle. The objective of this study was to quantitatively evaluate the response of Angus × Hereford cross steers consuming the feed additive Mootral, which contains extracts of both garlic and citrus, on CH4 yield (g/kg dry matter intake [DMI]). Twenty steers were randomly assigned to two treatments: control (no additive) and Mootral supplied at 15 g/d in a completely randomized design with a 2-wk covariate and a 12-wk data collection periods. Enteric CH4 emissions were measured using the GreenFeed system during the covariate period and experimental weeks 2, 6, 9, and 12. CH4 yield (g/kg DMI) by steers remained similar in both treatments for weeks 2 to 9. In week 12, there was a significant decrease in CH4 yield (23.2%) in treatment compared to control steers mainly because the steers were consuming all the pellets containing the additive. However, overall CH4 yield (g/kg DMI) during the entire experimental period was not significantly different. Carbon dioxide yield (g/kg DMI) and oxygen consumption (g/kg DMI) did not differ between treatments during the entire experimental period. DMI, average daily gain, and feed efficiency also remained similar in control and supplemented steers. The in vivo results showed that Mootral may have a potential to be used as a feed additive to reduce enteric CH4 production and yield in beef cattle but needs further investigation under various dietary regimen.


2019 ◽  
Vol 78 (2) ◽  
Author(s):  
Adam Bednařík ◽  
Martin Blaser ◽  
Martin Rulik

Rivers are a natural source of methane (CH4) into the atmosphere and may contribute significantly to total CH4 emissions. Even though the details of sources of CH4 in rivers are not fully understood, weirs have been recognized as a hotspot of CH4 emissions. In this study, we investigated CH4 production and consumption in air-exposed river sediments along a cross-channel transect located upstream of a weir. Stable carbon isotopes were used for determination of individual methanogenic pathways. In order to understand the relationship between physicochemical and biological processes, additional parameters such as organic matter, grain median size, and carbon and nitrogen content were characterized as well. Generally, samples from the surface sediment layer (0-10 cm) had higher CH4 production than sediments from the deeper layer (10-20 cm) during the incubation experiments. Sediments near the bank zones and in the mid-channel were characterized by the highest organic carbon content (6.9 %) as well the highest methanogenic activity (2.5 mmol g-1 DW d-1). The CH4 production was predominated by H2/CO2 dependent methanogenesis in the surface sediment layer (0-10 cm), while the proportion of acetoclastic and hydrogenotrophic methanogenesis in the deeper sediment layer (10-20 cm) was balanced. The CH4 oxidation potential of sediments showed the same spatial pattern as observed for the CH4 production. Our results showed high spatial variability of sediment CH4 production and oxidation in the cross-channel profile upstream of the weir, whereas the highest CH4 dynamics were observed in the littoral zones. This variability was closely linked with the carbon and nitrogen content in the sediment samples.


Animals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1120 ◽  
Author(s):  
Juana C. Chagas ◽  
Mohammad Ramin ◽  
Sophie J. Krizsan

We assessed and ranked different dietary strategies for mitigating methane (CH4) emissions and other fermentation parameters, using an automated gas system in two in vitro experiments. In experiment 1, a wide range of dietary CH4 mitigation strategies was tested. In experiment 2, the two most promising CH4 inhibitory compounds from experiment 1 were tested in a dose-response study. In experiment 1, the chemical compounds 2-nitroethanol, nitrate, propynoic acid, p-coumaric acid, bromoform, and Asparagopsis taxiformis (AT) decreased predicted in vivo CH4 production (1.30, 21.3, 13.9, 24.2, 2.00, and 0.20 mL/g DM, respectively) compared with the control diet (38.7 mL/g DM). The 2-nitroethanol and AT treatments had lower molar proportions of acetate and higher molar proportions of propionate and butyrate compared with the control diet. In experiment 2, predicted in vivo CH4 production decreased curvilinearly, molar proportions of acetate decreased, and propionate and butyrate proportions increased curvilinearly with increased levels of AT and 2-nitroethanol. Thus 2-nitroethanol and AT were the most efficient strategies to reduce CH4 emissions in vitro, and AT inclusion additionally showed a strong dose-dependent CH4 mitigating effect, with the least impact on rumen fermentation parameters.


2016 ◽  
Vol 13 (6) ◽  
pp. 1919-1932 ◽  
Author(s):  
Chandrashekhar Deshmukh ◽  
Frédéric Guérin ◽  
David Labat ◽  
Sylvie Pighini ◽  
Axay Vongkhamsao ◽  
...  

Abstract. Methane (CH4) emissions from hydroelectric reservoirs could represent a significant fraction of global CH4 emissions from inland waters and wetlands. Although CH4 emissions downstream of hydroelectric reservoirs are known to be potentially significant, these emissions are poorly documented in recent studies. We report the first quantification of emissions downstream of a subtropical monomictic reservoir. The Nam Theun 2 Reservoir (NT2R), located in the Lao People's Democratic Republic, was flooded in 2008 and commissioned in April 2010. This reservoir is a trans-basin diversion reservoir which releases water into two downstream streams: the Nam Theun River below the dam and an artificial channel downstream of the powerhouse and a regulating pond that diverts the water from the Nam Theun watershed to the Xe Bangfai watershed. We quantified downstream emissions during the first 4 years after impoundment (2009–2012) on the basis of a high temporal (weekly to fortnightly) and spatial (23 stations) resolution of the monitoring of CH4 concentration. Before the commissioning of NT2R, downstream emissions were dominated by a very significant degassing at the dam site resulting from the occasional spillway discharge for controlling the water level in the reservoir. After the commissioning, downstream emissions were dominated by degassing which occurred mostly below the powerhouse. Overall, downstream emissions decreased from 10 GgCH4 yr−1 after the commissioning to 2 GgCH4 yr−1 4 years after impoundment. The downstream emissions contributed only 10 to 30 % of total CH4 emissions from the reservoir during the study. Most of the downstream emissions (80 %) occurred within 2–4 months during the transition between the warm dry season (WD) and the warm wet season (WW) when the CH4 concentration in hypolimnic water is maximum (up to 1000 µmol L−1) and downstream emissions are negligible for the rest of the year. Emissions downstream of NT2R are also lower than expected because of the design of the water intake. A significant fraction of the CH4 that should have been transferred and emitted downstream of the powerhouse is emitted at the reservoir surface because of the artificial turbulence generated around the water intake. The positive counterpart of this artificial mixing is that it allows O2 diffusion down to the bottom of the water column, enhancing aerobic methane oxidation, and it subsequently lowered downstream emissions by at least 40 %.


Animals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 21 ◽  
Author(s):  
Aklilu Alemu ◽  
Atmir Romero-Pérez ◽  
Rafael Araujo ◽  
Karen Beauchemin

A long-term study (112 days) was conducted to examine the effect of feeding encapsulated nitrate (NO3−), microencapsulated blend of essential oils (EO), and their combination on growth performance, feeding behavior, and enteric methane (CH4) emissions of beef cattle. A total of 88 crossbred steers were purchased and assigned to one of four treatments: (i) control, backgrounding high-forage diet supplemented with urea (1.17% in dietary DM); (ii) encapsulated NO3− (EN), control diet supplemented with 2.5% encapsulated NO3− as a replacement for urea (1.785% NO3− in the dietary DM); (iii) microencapsulated blend of EO (MBEO), control diet supplemented with 150 mg/kg DM of microencapsulated blend of EO and pepper extract; and (iv) EN + MBEO, control diet supplemented with EN and MBEO. There was no interaction (p ≥ 0.080) between EN and MBEO on average dry matter intake (DMI), average daily gain (ADG), gain to feed ratio (G:F), feeding behavior, and CH4 emission (using GreenFeed system), implying independent effects of feeding EN and MBEO. Feeding MBEO increased CH4 production (165.0 versus 183.2 g/day; p = 0.005) and yield (18.9 versus 21.4 g/kg DMI; p = 0.0002) but had no effect (p ≥ 0.479) on average DMI, ADG, G:F, and feeding behavior. However, feeding EN had no effect on ADG and G:F (p ≥ 0.119) but reduced DMI (8.9 versus 8.4 kg/day; p = 0.003) and CH4 yield (21.5 versus 18.7 g/kg DMI; p < 0.001). Feeding EN slowed (p = 0.001) the feeding rate (g of DM/min) and increased (p = 0.002) meal frequency (events/day). Our results demonstrate that supplementing diets with a blend of EO did not lower CH4 emissions and there were no advantages of feeding MBEO with EN. Inclusion of EN as a replacement for urea reduced CH4 emissions but had no positive impact on animal performance.


2016 ◽  
Vol 56 (7) ◽  
pp. 1035 ◽  
Author(s):  
D. Vyas ◽  
A. Alazzeh ◽  
S. M. McGinn ◽  
T. A. McAllister ◽  
O. M. Harstad ◽  
...  

The objective of this study was to test the efficacy of Propionibacterium strains to mitigate enteric methane (CH4) emissions in beef heifers fed a mixed diet. An experiment was conducted with 16 ruminally cannulated beef heifers fed a basal diet consisting of 60 : 40 barley silage : barley grain (DM basis). Treatments included: (1) Control, (2) Propionibacterium freudenreichii T114, (3) P. thoenii T159, and (4) P. freudenreichii T54. Strains (1 × 1011 colony forming units) were administered daily directly into the rumen before feeding. No treatment effects were observed for DM intake (P = 0.90), mean ruminal pH (P = 0.50) and total volatile fatty acids (P = 0.44). However, compared with the Control, proportions of individual volatile fatty acids changed with acetate being less with Propionibacterium T159 (P = 0.02), whereas ruminal isobutyrate (P < 0.01) and acetate : propionate ratio (P = 0.04) were greater with Propionibacterium T114. Total daily enteric CH4 production averaged 188 g/day and was not affected by Propionbacterium strains (P = 0.51). Methane yield averaged 22 g/kg of DMI intake and tended to be greater with Propionibacterium strains (P = 0.08). The relative abundance of total Propionibacteria was greater with the inoculation of Propionibacterium T159 relative to the Control heifers (P = 0.04). In conclusion, inoculation of Propionibacterium T159 decreased ruminal acetate proportion and Propionibacterium T114 increased acetate : propionate ratio. However, inoculated strains failed to lower total CH4 emissions possibly due to the inability of Propionibacterium strains to elevate ruminal propionate concentrations.


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