Methane production in different breeds, grazing different pastures or fed a total mixed ration, as measured by a Laser Methane Detector (original) (raw)
Related papers
Animals
Methane (CH4) emissions represent a worldwide problem due to their direct involvement in atmospheric warming and climate change. Ruminants are among the major players in the global scenario of CH4 emissions, and CH4 emissions are a problem for feed efficiency since enteric CH4 is eructed to the detriment of milk and meat production. The collection of CH4 phenotypes at the population level is still hampered by costly and time-demanding techniques. In the present study, a laser methane detector was used to assess repeatability and reproducibility of CH4 phenotypes, including mean and aggregate of CH4 records, slope of the linear equation modelling the aggregate function, and mean and number of CH4 peak records. Five repeated measurements were performed in a commercial farm on three Simmental heifers, and the same protocol was repeated over a period of three days. Methane emission phenotypes expressed as parts per million per linear meter (ppm × m) were not normally distributed and, th...
Evaluation of the laser methane detector to estimate methane emissions from ewes and steers
Journal of Animal Science, 2014
The laser methane detector (LMD) has been proposed as a method to characterize enteric methane (CH 4) emissions from animals in a natural environment. To validate LMD use, its CH 4 outputs (LMD-CH 4), were compared against CH 4 measured with respiration chambers (chamber-CH 4). The LMD was used to measure CH 4 concentration (µL/L) in the exhaled air of 24 lactating ewes and 72 finishing steers. In ewes, LMD was used on 1 d for each ewe, for 2-min periods at 5 hourly observation periods (P1 to P5, respectively) after feeding. In steers fed either low-or high-concentrate diets, LMD was used once daily for a 4-min period for 3 d. The week after LMD-CH 4 measurement, ewes or steers entered respiration chambers to quantify daily CH 4 output (g/d). The LMD outputs consisted of periodic events of high CH 4 concentrations superimposed on a background of oscillating lower CH 4 concentrations. The high CH 4 events were attributed to eructation and the lower background CH 4 to respiration. After fitting a double normal distribution to the data set, a threshold of 99% of probability of the lower distribution was used to separate respiration from eructation events. The correlation between mean LMD-CH 4 and chamber-CH 4 was not high, and only improved correlations were observed after data were separated in 2 levels. In ewes, a model with LMD and DMI (adjusted R 2 = 0.92) improved the relationship between DMI and chamber-CH 4 alone (adjusted R 2 = 0.79) and between LMD and chamber-CH 4 alone (adjusted R 2 = 0.86). In both experiments, chamber-CH 4 was best explained by models with length of eructation events (time) and maximum values of CH 4 concentration during respiration events (µL/L; P < 0.01). Correlation between methods differed between observation periods, indicating the best results of the LMD were observed from 3 to 5 h after feeding. Given the short time and ease of use of LMD, there is potential for its commercial application and fieldbased studies. Although good indicators of quantity of CH 4 were obtained with respiration and eructation CH 4 , the method needed to separate the data into high and low levels of CH 4 was not simple to apply in practice. Further assessment of the LMD should be performed in relation to animal feeding behavior and physiology to validate assumptions of eructation and respiration levels, and other sources of variation should be tested (i.e., micrometeorology) to better investigate its potential application for CH 4 testing in outdoor conditions.
Laser methane detector-based quantification of methane emissions from indoor-fed Fogera dairy cows
2021
Objective Portable laser methane detectors (LMDs) may be an economical means of estimating CH4 emissions from ruminants. We validated an LMD-based approach and then used that approach to evaluate CH4 emissions from indigenous dairy cows in a dryland area of Ethiopia. Methods First, we validated our LMD-based approach in Simmental crossbred beef cattle (n = 2) housed in respiration chambers and fed either a high- or low-concentrate diet. From the results of the validation, we constructed an estimation equation to determine CH4 emissions from LMD CH4 concentrations. Next, we used our validated LMD approach to examine CH4 emissions in Fogera dairy cows grazed for 8 h/d (GG, n = 4), fed indoors on natural-grassland hay (CG1, n = 4), or fed indoors on Napier-grass (Pennisetum purpureum) hay (CG2, n = 4). All the cows were supplemented with concentrate feed. Results The exhaled CH4 concentrations measured by LMD were linearly correlated with the CH4 emissions determined by infrared-absorp...
Methane Production in Ruminant Animals
Measuring Emission of Agricultural Greenhouse Gases and Developing Mitigation Options using Nuclear and Related Techniques, 2021
Agriculture is a significant source of GHGsglobally and ruminant livestock animals are one of the largest contributors to these emissions, responsible for an estimated 14% of GHGs (CH4and N2O combined) worldwide. A large portion of GHG fluxes from agricultural activities is related to CH4 emissions from ruminants. Both direct and indirect methods are available. Direct methods include enclosure techniques, artificial (e.g. SF6) or natural (e.g. CO2) tracer techniques, and micrometeorological methods using open-path lasers. Under the indirect methods, emission mechanisms are understood, where the CH4 emission potential is estimated based on the substrate characteristics and the digestibility (i.e. from volatile fatty acids). These approximate methods are useful if no direct measurement is possible. The different systems used to quantify these emission potentials are presented in this chapter. Also, CH4 from animal waste (slurry, urine, dung) is an important source: methods per...
Computers and Electronics in Agriculture, 2018
The Laser Methane Detector (LMD) technique has proven to be reliable for estimating enteric methane (CH 4) output in ruminants. The number of peer-reviewed publications related to LMD measurements in ruminants is still small. Studies are largely limited to measurements of animals in controlled research environment and respiration chambers, while measurements on animals outside respiration chambers are rare. Most studies focused on cattle or sheep, but the LMD has not yet been applied to goats. Finally, no systematic measurement protocol is available for different livestock species. Thus, the experimental setup of studies varies considerably, making a comparison of results difficult, although previous papers have provided guidance. In the present study, the LMD technique was applied in two experiments with goats to evaluate the effect of; the position of goats, the time after feeding, CH 4 peaks and troughs, the recording interval and the proportion of concentrate feed and hay in the diet on enteric CH 4 emission. Measurements were taken on four (Experiment 1) and 12 (Experiment 2) 1-year old female Boer goats. The position affected the mean enteric CH 4 emission, with higher values for lying than for standing goats. However, results across goats differ. In contrast, a day effect was observed that was consistent across positions and goats, with highest CH 4 emissions obtained for day 3 (Experiment 1). As could be expected, the time after feeding strongly influenced the CH 4 concentrations that were highest directly after morning feeding. CH 4 concentrations gradually decreased with increasing time after feeding and were lowest early in the morning. No diet effect (quality and quantity) was observed (Experiment 2). This indicates a high individual variation of enteric CH 4 emissions that could be exploited to select and breed animals with lower CH 4 output. For subsequent experiments utilizing the LMD technique, it is recommended to use a 0.1-s interval for recording point measurements of CH 4 concentrations, and for analysis to consider peaks only. A reduction of the recording interval to 1 s and 4 s only using CH 4 peaks led to high deviances from the reference (0.1-s records, CH 4 peaks and troughs), whereas the 0.1-s recording interval cleaned from CH 4 troughs and using only CH 4 peaks showed good accordance with the reference. Ongoing studies will verify the present results in view of developing a standardized protocol for measuring CH 4 output in the major ruminant livestock species.
Livestock Science, 2010
This technical note presents a simple, fast, reliable and cheap method to estimate the methane (CH 4 ) production from animals by using the CH 4 and carbon dioxide (CO 2 ) concentrations in air near the animals combined with an estimation of the total CO 2 production from information on intake of metabolizable energy or heat producing units. By using portable equipment to analyse the air in stables or near individual animals it is possible to calculate the proportion of the carbon that is not metabolized to CO 2 , but excreted as the greenhouse gas CH 4 . The CH 4 /CO 2 proportion in itself gives useful information and can be seen on the spot when measuring. A more detailed use of the data in combination with feedstuff analysis can be used to estimate the quantitative CH 4 production from the animals as the CO 2 excretion can be calculated from the intake of metabolizable energy minus the energy in the weight gain or milk produced, as there is close relation between heat production and CO 2 excretion. Moreover, data from air analysis in livestock buildings shows a close relation between CO 2 production and the amount of heat producing units (HPU) in a stable, which also in this situation makes CO 2 a good marker for the quantitative excretion of gases and thereby a marker to be used for the calculation of the quantitative CH 4 production from livestock.
Quantification of methane emitted by ruminants: a review of methods
Journal of Animal Science
The contribution of greenhouse gas (GHG) emissions from ruminant production systems varies between countries and between regions within individual countries. The appropriate quantification of GHG emissions, specifically methane (CH4), has raised questions about the correct reporting of GHG inventories and, perhaps more importantly, how best to mitigate CH4 emissions. This review documents existing methods and methodologies to measure and estimate CH4 emissions from ruminant animals and the manure produced therein over various scales and conditions. Measurements of CH4 have frequently been conducted in research settings using classical methodologies developed for bioenergetic purposes, such as gas exchange techniques (respiration chambers, headboxes). While very precise, these techniques are limited to research settings as they are expensive, labor-intensive, and applicable only to a few animals. Head-stalls, such as the GreenFeed system, have been used to measure expired CH4 for ind...
Direct measurements of methane emissions from grazing and feedlot cattle
Journal of Animal Science
Methane (CH4) emissions from animals represent a significant contribution to anthropogenically produced radiatively active trace gases. Global and national CH4 budgets currently use predictive models based on emission data from laboratory experiments to estimate the magnitude of the animal source. This paper presents a method for measuring CH4 from animals under undisturbed field conditions and examines the performance of common models used to simulate field conditions. A micrometeorological mass difference technique was developed to measure CH4 production by cattle in pasture and feedlot conditions. Measurements were made continuously under field conditions, semiautomatically for several days, and the technique was virtually nonintrusive. The method permits a relatively large number of cattle to be sampled. Limitations include light winds (less than approximately 2 m/s), rapid wind direction changes, and high-precision CH4 gas concentration measurement. Methane production showed a ...
Journal of Dairy Science, 2020
Since heritability of CH 4 emissions in ruminants was demonstrated, various attempts to generate large individual animal CH 4 data sets have been initiated. Predicting individual CH 4 emissions based on equations using milk mid-infrared (MIR) spectra is currently considered promising as a low-cost proxy. However, the CH 4 emission predicted by MIR in individuals still has to be confirmed by measurements. In addition, it remains unclear how low CH 4 emitting cows differ in intake, digestion, and efficiency from high CH 4 emitters. In the current study, putatively low and putatively high CH 4 emitting Brown Swiss cows were selected from the entire Swiss herdbook population (176,611 cows), using an MIR-based prediction equation. Eventually, 15 low and 15 high CH 4 emitters from 29 different farms were chosen for a respiration chamber (RC) experiment in which all cows were fed the same forage-based diet. Several traits related to intake, digestion, and efficiency were quantified over 8 d, and CH 4 emission was measured in 4 open circuit RC. Daily CH 4 emissions were also estimated using data from 2 laser CH 4 detectors (LMD). The MIR-predicted CH 4 production (g/d) was quite constant in low and high emission categories, in individuals across sites (home farm, experimental station), and within equations (first available and refined versions). The variation of the MIR-predicted values was substantially lower using the refined equation. However, the predicted low and high emitting cows (n = 28) did not differ on average in daily CH 4 emissions measured either with RC or estimated using LMD, and no correlation was found between CH 4 predictions (MIR) and CH 4 emissions measured in RC. When individuals were recategorized based on CH 4 yield measured in RC, differences between categories of 10 low and 10 high CH 4 emitters were about 20%. Low CH 4 emitting cows had a higher feed intake, milk yield, and residual feed intake, but they differed only weakly in eating pattern and digesta mean retention times. Low CH 4 emitters were characterized by lower acetate and higher propionate proportions of total ruminal volatile fatty acids. We concluded that the current MIR-based CH 4 predictions are not accurate enough to be implemented in breeding programs for cows fed forage-based diets. In addition, low CH 4 emitting cows have to be characterized in more detail using mechanistic studies to clarify in more detail the properties that explain the functional differences found in comparison with other cows.