| 1. |
- Guinguina, Abdulai, et al.
(författare)
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Between-cow variation in the components of feed efficiency
- 2020
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 103, s. 7968-7982
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Tidskriftsartikel (refereegranskat)abstract
- A meta-analysis based on an individual-cow data set was conducted to investigate between-cow variations in the components and measurements of feed efficiency (FE) and to explore the associations among these components. Data were taken from 31 chamber studies, consisting of a total of 841 cow/period observations. The experimental diets were based on grass or corn silages, fresh grass, or a mixture of fresh grass and straw, with cereal grains or by-products as energy supplements, and soybean or canola meal as protein supplements. The average forage-to-concentrate ratio across all diets on a dry matter basis was 56:44. Variance component and repeatability estimates of FE measurements and components were determined using diet, period, and cow within experiment as random effects in mixed procedures of SAS (SAS Institute Inc., Cary, NC). The between-cow coefficient of variation (CV) in gross energy intake (GE; CV = 0.10) and milk energy (El) output as a proportion of GE (El/GE; CV = 0.084) were the largest among all component traits. Similarly, the highest repeatability estimates (≥0.50) were observed for these 2 components. However, the between-cow CV in digestibility (DE/GE), metabolizability [metabolizable energy (ME)/GE], methane yield (CH4E/GE), proportional urinary energy output (UE/GE), and heat production (HP/GE), as well as the efficiency of ME use for lactation (kl), were rather small. The least repeatable component of FE was UE/GE. For FE measurements, the between-cow CV in residual energy-corrected milk (RECM) was larger than for residual feed intake (RFI), suggesting a greater possibility for genetic gain in RECM than in RFI. A high DE/GE was associated with increased CH4E/GE (r = 0.24), HP/GE (r = 0.12), ME/GE (r = 0. 91), energy balance as a proportion of GE (EB/GE; r = 0.35), and kl (r = 0.10). However, no correlation between DE/GE and GE intake or UE/GE was observed. Increased proportional milk energy adjusted to zero energy balance (El(0)/GE) was associated with increases in DE/GE, ME/GE, EB/GE, and kl but decreases in UE/GE, CH4E/GE, and HP/GE, with no effect on GE intake. In conclusion, several mechanisms are involved in the observed differences in FE among dairy cows, and reducing CH4E yield (CH4E/GE) may inadvertently result in reduced GE digestibility. However, the selection of dairy cows with improved energy utilization efficiencies offers an effective approach to lower enteric CH4 emissions.
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| 2. |
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| 3. |
- Guinguina, Abdulai
(författare)
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Feed efficiency in dairy cows: individual cow variability in component traits
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Feed efficiency (FE) varies between cows, and this variation is linked to the variation in energy metabolism variables. Respiration chambers are needed for measuring energy metabolism variables while individual cow dry matter intake (DMI) records are necessary for measuring FE, but these are difficult to obtain due to cost and logistic constraints. This thesis evaluated the between-cow coefficient of variation (CV) in the components of FE and their contribution to FE. Also, marker techniques of measuring DMI and the use of an upgraded GreenFeed system (GF) to measure energy balance (EB) in lactating dairy cows were evaluated. Marker-based estimates of DMI underestimated observed DMI. The use of external markers for faecal output estimates gave the best prediction of FE suggesting that faecal output measurements with external markers are enough to determine FE thereby removing the need for analysing feed samples. However, the direct measurement was more precise making it a method of choice unless otherwise not feasible due to facility limitations. The between-cow CV in gross energy (GE) intake was the highest among all component traits while that of digestibility (DE/GE) was small. Although the between-cow CV in methane (CH4) as a proportion of GE was important, it was positively correlated with DE/GE, suggesting that selecting for low CH4 emitters may result in unintended selection for low DE/GE which is an important trait for ruminants. The between-cow CV in residual energy corrected milk (RECM) was double that of residual feed intake (RFI) indicating that RECM is more amenable to genetic selection than RFI. Using respiration chamber data to predict DMI and ECM for RFI and RECM calculations, respectively, the partial regression coefficients were biologically meaningful. About 65% of the difference between low and high-FE (RFI or RECM) cows was due to improved utilisation of metabolisable energy. Residual CO2 could be the FE index of the future as it eliminates the need for measuring individual animal DMI. The replacement of cereal grain with by-product did not have negative effects on production and EB, suggesting that by-product can replace cereal grain in early lactation cow diets. The GF proved to be a promising tool for measuring EB. Milk mid-infrared (MIR) spectral data also gave a good prediction of EB which presents an opportunity to estimate individual cow EB without added investments as MIR is an on-farm routine analysis.
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| 4. |
- Guinguina, Abdulai, et al.
(författare)
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Postpartum responses of dairy cows supplemented with cereal grain or fibrous by-product concentrate
- 2021
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 28
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Tidskriftsartikel (refereegranskat)abstract
- The present study examined the effect of replacing cereal grain with a fibrous by-product concentrate on nutrient intake, milk production traits and fatty acid composition, diet digestibility, feed conversion efficiency (FCE), CH4 and CO2 emissions, and plasma blood parameters of dairy cows in early lactation. Twenty-two Nordic Red cows were randomly assigned to one of two dietary treatments immediately after calving until 18 weeks in lactation. The cereal grain treatment contained 593 g/kg of grass silage, 317 g/kg of cereal grain mixture (barley, oat, and wheat), 79 g/kg of heat-treated rapeseed meal, and 11 g/kg of a mineral mix on a DM basis. A mixture of unmolassed beet pulp, wheat middlings, barley fibre, and wheat bran replaced cereal grains in the by-product treatment. The diets were isocaloric and isonitrogenous and were fed ad libitum as total mixed rations. The by-product diet had a higher fibre content, while starch content was reduced compared with the cereal grain diet. Despite the 12 %-unit difference in dietary starch content, no differences in DMI were observed. Similarly, no differences in body weight and body condition score (BCS) were observed between treatments. Cows fed the fibrous by-product diet had lower apparent total-tract digestibility of DM (683 g/kg), organic matter (700 g/kg), and crude protein (665 g/kg) compared to those fed cereal grain diet (735, 749, and 699 g/kg, respectively), but milk yield and composition, as well as FCE were not affected by treatment. The edible feed conversion ratio in the by-product group was on average 3.7- folds higher than the cereal grain group. Total CH4 emission (g/d) and CH4 yield (g/kg DMI) reduced by 10.3% on average when by-product replaced cereal grains, but CH4 intensity (g CH4/kg ECM) was not significantly influenced by diet. Although the feeding of by-product had no effect on milk fat content, it changed its fatty acid profile by increasing the proportion of some unsaturated fatty acids (ƩC18:1 trans, C18:3 cis-9 cis-12 cis-15, omega-3) in milk fat. Replacing cereal grain with fibrous by-product in the diets of early lactation dairy cows had no effect on their risk of developing metabolic disorders. These findings suggest that cows fed grass silage-based diets can be supplemented with fibrous by-product concentrates without affecting feed efficiency or energy balance status, thereby supporting sustainable food production. However, future works should evaluate the economic aspects of feeding by-product concentrates to determine their practical application for feed manufacturers and farmers.
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| 5. |
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| 6. |
- Guinguina, Abdulai, et al.
(författare)
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Potential of the Red Macroalga Bonnemaisonia hamifera in Reducing Methane Emissions from Ruminants
- 2023
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Ingår i: Animals. - : Multidisciplinary Digital Publishing Institute (MDPI). - 2076-2615. ; 13:18
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Tidskriftsartikel (refereegranskat)abstract
- Researchers have been exploring seaweeds to reduce methane (CH4) emissions from livestock. This study aimed to investigate the potential of a red macroalga, B. hamifera, as an alternative to mitigate CH4 emissions. B. hamifera, harvested from the west coast of Sweden, was used in an in vitro experiment using a fully automated gas production system. The experiment was a randomized complete block design consisting of a 48 h incubation that included a control (grass silage) and B. hamifera inclusions at 2.5%, 5.0%, and 7.5% of grass silage OM mixed with buffered rumen fluid. Predicted in vivo CH4 production and total gas production were estimated by applying a set of models to the gas production data and in vitro fermentation characteristics were evaluated. The results demonstrated that the inclusion of B. hamifera reduced (p = 0.01) predicted in vivo CH4 and total gas productions, and total gas production linearly decreased (p = 0.03) with inclusion of B. hamifera. The molar proportion of propionate increased (p = 0.03) while isovalerate decreased (p = 0.04) with inclusion of B. hamifera. Chemical analyses revealed that B. hamifera had moderate concentrations of polyphenols. The iodine content was low, and there was no detectable bromoform, suggesting quality advantages over Asparagopsis taxiformis. Additionally, B. hamifera exhibited antioxidant activity similar to Resveratrol. The findings of this study indicated that B. hamifera harvested from temperate waters of Sweden possesses capacity to mitigate CH4 in vitro.
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| 7. |
- Guinguina, Abdulai, et al.
(författare)
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Predicting feed intake and feed efficiency in lactating dairy cows using digesta marker techniques
- 2019
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 13, s. 2277-2288
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Tidskriftsartikel (refereegranskat)abstract
- Direct measurement of individual animal dry matter intake (DMI) remains a fundamental challenge to assessing dairy feed efficiency (FE). Digesta marker, is currently the most used indirect technique for estimating DMI in production animals. In this meta-analysis we evaluated the performance of marker-based estimates against direct or observed measurements and developed equations for the prediction of FE (g energy-corrected milk (ECM)/kg DMI). Data were taken from 29 change-over studies consisting of 416 cow-within period observations. Most studies used more than one digesta marker. So, for each observed measurement of DMI, faecal dry matter output (FDMO) and apparent total tract dry matter digestibility (DMD), there was one or more corresponding marker estimate. There were 924, 409 and 846 observations for estimated FDMO (eFDMO), estimated apparent total tract DMD (eDMD) and estimated DMI (eDMI), respectively. The experimental diets were based mainly on grass silage, with soya bean or rapeseed meal as protein supplements and cereal grains or by-products as energy supplements. Across all diets, average forage to concentrate ratio on a dry matter (DM) basis was 59 : 41. Variance component and repeatability estimates of observed and marker estimations were determined using random factors in mixed procedures of SAS. Between-cow CV in observed FDMO, DMD and DMI was, 10.3, 1.69 and 8.04, respectively. Overall, the repeatability estimates of observed variables were greater than their corresponding marker-based estimates of repeatability. Regression of observed measurements on marker-based estimates gave good relationships (R-2=0.87, 0.68, 0.74 and 0.74, relative prediction error =10.9%, 6.5%, 15.4% and 18.7%for FDMO, DMD, DMI and FE predictions, respectively). Despite this, the mean and slope biases were statistically significant (P<0.001) for all regressions. More than half of the errors in all regressions were due to mean and slope biases (52.4% 87.4%, 82.9% and 85.8% for FDMO, DMD, DMI and FE, respectively), whereas the contributions of random errors were small. Based on residual variance, the best model for predicting FE developed from the dataset was FE (g ECM/kg DMI)=1179(+/- 54.1) +38.2(+/- 2.05)xECM(kg/day)-0.64(+/- 0.051)xBW (kg)-75.6(+/- 4.39)xeFDMO (kg/day). Although eDMD was positively related to FE, it only showed a tendency to reduce the residual variance. Despite inaccuracy in marker procedures, eFDMO from external markers provided a reliable determination for FE measurement. However, DMD estimated by internal markers did not improve prediction of FE, probably reflecting small variability.
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| 8. |
- Guinguina, Abdulai
(författare)
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Review: In vivo and postmortem effects of feed antioxidants in livestock: a review of the implications on authorization of antioxidant feed additives
- 2016
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 10, s. 1375-1390
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Forskningsöversikt (refereegranskat)abstract
- The pivotal roles of regulatory jurisdictions in the feed additive sector cannot be over-emphasized. In the European Union (EU), antioxidant substances are authorized as feed additives for prolonging the shelf life of feedstuffs based on their effect for preventing lipid peroxidation. However, the efficacy of antioxidants transcends their functional use as technological additives in animal feeds. Promising research results have revealed the in vivo efficacy of dietary antioxidants for combating oxidative stress in production animals. The in vivo effect of antioxidants is significant for enhancing animal health and welfare. Similarly, postmortem effect of dietary antioxidants has been demonstrated to improve the nutritional, organoleptic and shelf-life qualities of animal products. In practice, dietary antioxidants have been traditionally used by farmers for these benefits in livestock production. However, some antioxidants particularly when supplemented in excess could act as prooxidants and exert detrimental effects on animal well-being and product quality. Presently, there is no exclusive legislation in the EU to justify the authorization of antioxidant products for these in vivo and postmortem efficacy claims. To indicate these efficacy claims and appropriate dosage on product labels, it is important to broaden the authorization status of antioxidants through the appraisal of existing EU legislations on feed additives. Such regulatory review will have major impact on the legislative categorization of antioxidants and the efficacy assessment in the technical dossier application. The present review harnesses the scientific investigations of these efficacy claims in production animals and, proposes potential categorization and appraisal of in vivo methodologies for efficacy assessment of antioxidants. This review further elucidates the implication of such regulatory review on the practical application of antioxidants as feed additives in livestock production. Effecting these regulatory changes will stimulate the innovation of more potent antioxidant products and create potential new markets that will have profound economic impacts on the feed additive industry. Based on the in vivo efficacy claims, antioxidants may have to contend with the legislative controversy of either to be considered as veterinary drugs or feed additives. In this scenario, antioxidants are not intended to diagnose or cure diseases as ascribed to veterinary products. This twisted distinction can be logically debated with reference to the stipulated status of feed additives in Commission Regulation (EC) No 1831/2003. Nonetheless, it is imperative for relevant stakeholders in the feed additive industry to lobby for the review of existing EU legislations for authorization of antioxidants for these efficacy claims.
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| 9. |
- Guinguina, Abdulai, et al.
(författare)
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The effects of energy metabolism variables on feed efficiency in respiration chamber studies with lactating dairy cows
- 2020
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 103, s. 7983-7997
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the present study was to investigate factors related to variation in feed efficiency (FE) among cows. Data included 841 cow/period observations from 31 energy metabolism studies assembled across 3 research stations. The cows were categorized into low-, medium-, and high-FE groups according to residual feed intake (RFI), residual energy-corrected milk (RECM), and feed conversion efficiency (FCE). Mixed model regression was conducted to identify differences among the efficiency groups in animal and energy metabolism traits. Partial regression coefficients of both RFI and RECM agreed with published energy requirements more closely than cofficients derived from production experiments. Within RFI groups, efficient (Low-RFI) cows ate less, had a higher digestibility, produced less methane (CH4) and heat, and had a higher efficiency of metabolizable energy (ME) utilization for milk production. High-RECM (most efficient) cows produced 6.0 kg/d more of energy-corrected milk (ECM) than their Low-RECM (least efficient) contemporaries at the same feed intake. They had a higher digestibility, produced less CH4 and heat, and had a higher efficiency of ME utilization for milk production. The contributions of improved digestibility, reduced CH4, and reduced urinary energy losses to increased ME intake at the same feed intake were 84, 12, and 4%, respectively. For both RFI and RECM analysis, increased metabolizability contributed to approximately 35% improved FE, with the remaining 65% attributed to the greater efficiency of utilization of ME. The analysis within RECM groups suggested that the difference in ME utilization was mainly due to the higher maintenance requirement of Low-RECM cows compared with Medium- and High-RECM cows, whereas the difference between Medium- and High-RECM cows resulted mainly from the higher efficiency of ME utilization for milk production in High-RECM cows. The main difference within FCE (ECM/DMI) categories was a greater (8.2 kg/d) ECM yield at the expense of mobilization in High-FCE cows compared with Low-FCE cows. Methane intensity (CH4/ECM) was lower for efficient cows than for inefficient cows. The results indicated that RFI and RECM are different traits. We concluded that there is considerable variation in FE among cows that is not related to dilution of maintenance requirement or nutrient partitioning. Improving FE is a sustainable approach to reduce CH4 production per unit of product, and at the same time improve the economics of milk production.
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| 10. |
- Guinguina, Abdulai, et al.
(författare)
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The use of an upgraded GreenFeed system and milk fatty acids to estimate energy balance in early-lactation cows
- 2021
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 104, s. 6701-6714
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of energy balance (EB) require the use of respiration chambers, which are quite expensive and laborious. The GreenFeed (GF) system (C-Lock Inc.) has been developed to offer a less expensive, user friendly alternative. In this study, we used the GF system to estimate the EB of cows in early lactation and compared it with EB predicted from energy requirements for dairy cows in the Finnish feeding standards. We also evaluated the association between milk fatty acids and the GF estimated EB. The cows were fed the same grass silage but supplemented with either cereal grain or fibrous by-product concentrate. Cows were followed from 1 to 18 wk of lactation, and measurements of energy metabolism variables were taken. Data were subjected to ANOVA using the mixed model procedure of SAS (SAS Institute Inc.). The repeatability estimates of the gaseous exchanges from the GF were moderate to high, presenting an opportunity to use it for indirect calorimetry in EB estimates. Energy metabolism variables were not different between cows fed different concentrates. However, cows fed the grain concentrate produced more methane (24.0 MJ/d or 62.9 kJ/MJ of gross energy) from increased digestibility than cows fed the by-product concentrate (21.3 MJ/d or 56.5 kJ/MJ of gross energy). Nitrogen metabolism was also not different between the diets. Milk long-chain fatty acids displayed an inverse time course with EB and de novo fatty acids. There was good concordance (0.85) between EB predicted using energy requirements derived from the Finnish feed table and EB estimated by the GF system. In conclusion, the GF can accurately estimate EB in early-lactating dairy cows. However, more data are needed to further validate the system for a wide range of dietary conditions.
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| 11. |
- Huhtanen, Pekka, et al.
(författare)
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Residual carbon dioxide as an index of feed efficiency in lactating dairy cows
- 2021
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 104, s. 5332-5344
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Tidskriftsartikel (refereegranskat)abstract
- High feed costs make feed conversion efficiency a desirable target for genetic improvement. Residual feed intake (RFI), calculated as the difference between observed and predicted intake, is a commonly used estimate of feed efficiency. However, determination of feed efficiency in dairy herds is challenging due to difficulties in measuring feed intake of individual animals reliably. Using residual CO2 (RCO2) production as an estimate of feed efficiency would allow ranking the cows according to feed efficiency, provided that CO2 production is closely related to heat production and feed intake. The objective of this study was to evaluate the potential of RCO2 as an index of feed efficiency using data from respiration calorimetry studies (289 cow per period observations). Heat production was precisely predicted from CO2 production [root mean square error (RMSE)] adjusted for random effects was 1.5% of observed mean]. Dry matter intake (DMI) was better predicted from energy-corrected milk (ECM) yield and CO2 production than from ECM yield and body weight in the model (adjusted RSME = 0.92 vs. 1.39 kg/d). Residual CO2 production estimated as the difference between actual CO2 production and that predicted from ECM yield, metabolic body weight was closely related to RFI (adjusted RMSE = 0.42) that was calculated as the difference between actual DMI and that predicted from ECM, metabolic body weight, and energy balance (EB). When the cows were categorized in 3 groups of equal sizes on the basis of RCO2 (low, medium, and high), low RCO2 cows had lower DMI, RFI, methane production and intensity (g/ kg ECM), and heat production, but higher efficiency of metabolizable energy utilization for lactation than high RCO2 cows. When RFI was predicted from RCO2, the residuals (observed - predicted) were negatively related to EB and digestibility. Predicting RFI with a 2-variable model based on RCO2 and digestibility, adjusted RMSE decreased to 0.23 kg/d, and residuals were not significantly related to EB. The cows in low RCO2 group had a higher energy digestibility than the cows in the high RCO2 group, and differences in EB were observed between the groups. Error of the model predicting residual ECM production from RCO2 was 1.41 kg/d. The residuals were positively related to ECM yield and energy digestibility. Predicting residual ECM from RCO2 and ECM yield decreased adjusted RMSE to 1.07 kg/d, and further to 0.78 kg/d when digestibility was included in the 2-variable model. It is concluded that RCO2 has a potential for ranking individual cows based on feed efficiency.
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| 12. |
- Ramin, Mohammad, et al.
(författare)
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Contemporary approaches to measuring and estimating methane emission from ruminants
- 2022
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Ingår i: Methane. - : MDPI AG. - 2674-0389. ; 1, s. 82-95
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Forskningsöversikt (refereegranskat)abstract
- This review aims to elucidate the contemporary methods of measuring and estimating methane (CH4) emissions from ruminants. Six categories of methods for measuring and estimating CH4 emissions from ruminants are discussed. The widely used methods in most CH4 abatement experiments comprise the gold standard respiration chamber, in vitro incubation, and the sulfur hexafluoride (SF6) techniques. In the spot sampling methods, the paper discusses the sniffer method, the GreenFeed system, the face mask method, and the portable accumulation chamber. The spot sampling relies on the measurement of short-term breath data adequately on spot. The mathematical modeling methods focus on predicting CH4 emissions from ruminants without undertaking extensive and costly experiments. For instance, the Intergovernmental Panel on Climate Change (IPCC) provides default values for regional emission factors and other parameters using three levels of estimation (Tier 1, 2 and 3 levels), with Tier 1 and Tier 3 being the simplest and most complex methods, respectively. The laser technologies include the open-path laser technique and the laser CH4 detector. They use the laser CH4 detector and wireless sensor networks to measure CH4 flux. The micrometeorological methods rely on measurements of meteorological data in line with CH4 concentration. The last category of methods for measuring and estimating CH4 emissions in this paper is the emerging technologies. They include the blood CH4 concentration tracer, infrared thermography, intraruminal telemetry, the eddy covariance (EC) technique, carbon dioxide as a tracer gas, and polytunnel. The emerging technologies are essential for the future development of effective quantification of CH4 emissions from ruminants. In general, adequate knowledge of CH4 emission measurement methods is important for planning, implementing, interpreting, and comparing experimental results.
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