scholarly journals Updated predictions of enteric methane emissions from sheep suitable for use in the New Zealand national greenhouse gas inventory

2018 ◽  
Vol 58 (6) ◽  
pp. 973 ◽  
Author(s):  
Natasha Swainson ◽  
Stefan Muetzel ◽  
Harry Clark
Keyword(s):  
New Zealand ◽  
Greenhouse Gas ◽  
Sulfur Hexafluoride ◽  
Single Equation ◽  
Greenhouse Gas Inventory ◽  
Ch4 Emissions ◽  
National Inventory ◽  
Enteric Methane ◽  
Metabolisable Energy ◽  
Carbon Dioxide Equivalent

Enteric methane (CH4) emissions make up approximately one-third of all New Zealand’s carbon dioxide equivalent greenhouse gas emissions. In current national inventory calculations, fixed values are used to estimate emissions from sheep; 20.9 g CH4 per kg dry matter intake (DMI) for sheep <1 year old and 16.8 g CH4 per kg DMI for sheep >1 year old. These values have been principally derived from trials where intake was estimated, and CH4 emissions were measured indirectly using the sulfur hexafluoride tracer technique. Using New Zealand sheep data collected between 2009 and 2015, where intake was accurately measured and CH4 emissions were measured for a minimum of 48 h in respiration chambers (n = 817), updated sheep methane prediction algorithms suitable for use in the national greenhouse gas inventory were derived. A single equation for all sheep based on daily DMI (kg) alone (ln(g CH4/day) = 0.763 × ln(DMI) + 3.039) explained 76% of the variation in CH4 emissions. Splitting the dataset into two age classes (sheep <1 year old and sheep >1 year old) provided two alternative equations; (sheep >1 year old), ln(g CH4/day) = 0.765 × ln(DMI) + 3.09 and (sheep <1 year old), ln(g CH4/day) = 0.734 × ln(DMI) + 0.05(metabolisable energy) + 2.46. An analysis of concordance suggests that a better fit to the data is obtained by using a two-algorithm approach. The use of these updated algorithms in the national inventory resulted in small changes to estimated emissions both within and between years.

Methane emissions from young and mature dairy cattle

2016 ◽  
Vol 56 (11) ◽  
pp. 1897 ◽  
Author(s):  
C. A. Ramírez-Restrepo ◽  
H. Clark ◽  
S. Muetzel
Keyword(s):  
New Zealand ◽  
Emission Factor ◽  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Dry Matter Intake ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Age Related ◽  
The Mean

Daily methane (CH4) emissions (g) and CH4 yield (g/kg dry matter intake) were measured from 10 dairy heifers (<1 year old) and nine rumen-fistulated cows (>6 years old) fed ryegrass (Lolium perenne) chaffage indoors. The CH4 emissions were estimated using the sulfur hexafluoride tracer technique in four ~5-day periods beginning in June 2008 and repeated 4, 6 and 7 months later. Respiratory chambers were used in four ~13-day periods beginning in November 2008 and repeated 2, 5 and 6 months later. Third and fourth sulfur hexafluoride tracer periods overlapped with the first and second chamber measurement periods, respectively. Averaged over the four measurement periods the CH4 yields determined using both techniques were similar for heifers and cows. The mean CH4 yield estimated by the sulfur hexafluoride tracer technique was 25.3 ± 0.52 for heifers and 24.1 ± 0.55 for mature cows, whereas the mean CH4 yield measured in respiratory chambers was 23.7 ± 0.66 for heifers and 23.6 ± 0.66 for mature cows. Averaged over the eight measurements irrespective of technique, CH4 yields for heifers (24.5 ± 0.42) and cows (23.8 ± 0.43) were similar. There was also no difference between CH4 methods for assessing CH4 yield during the overlapping measurement periods. It was concluded that no consistent differences in CH4 yield existed between heifers and mature cows. Therefore, we do not recommend adoption of an age-related emission factor for cattle in the national inventory calculations for New Zealand.

scholarly journals Effect of Mootral—a garlic- and citrus-extract-based feed additive—on enteric methane emissions in feedlot cattle

2019 ◽  
Vol 3 (4) ◽  
pp. 1383-1388 ◽  
Author(s):  
Breanna M Roque ◽  
Henk J Van Lingen ◽  
Hilde Vrancken ◽  
Ermias Kebreab
Keyword(s):  
Beef Cattle ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Experimental Period ◽  
Feed Additive ◽  
Gas Emissions ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Enteric Methane

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.

Effect of feeding a balanced ration on milk production, microbial nitrogen supply and methane emissions in field animals

2014 ◽  
Vol 54 (10) ◽  
pp. 1657 ◽  
Author(s):  
M. R. Garg ◽  
P. L. Sherasia ◽  
B. T. Phondba ◽  
S. A. Hossain
Keyword(s):  
Milk Production ◽  
Sulfur Hexafluoride ◽  
Western Region ◽  
Ch4 Emissions ◽  
N Supply ◽  
Microbial Nitrogen ◽  
Metabolisable Energy ◽  
The Western Region ◽  
Effect Of Feeding ◽  
Microbial N

Dairy animals in developing countries produce more methane (CH4), primarily on account of feed rations imbalanced in nutrients. A field study on early lactating cows (n = 80) and buffaloes (n = 82) was conducted to evaluate the effect of feeding a balanced ration on milk production, microbial nitrogen (N) supply and CH4 emissions in different agroclimatic regions of India. CH4 emissions was measured using the sulfur hexafluoride tracer technique, before and after feeding a balanced ration. Feeding practices revealed that intake of protein was adequate in the ration of experimental animals in most of the regions, except for the buffaloes of the western region. Metabolisable energy (MJ/cow.day) intake was higher by 7.6% and 13.6% in cows of western and northern regions, respectively. In buffaloes, energy intake (MJ metabolisable energy/buffalo.day) was higher by 11.5% in the western region but lower by 17.7% in the central region. Average calcium intake was deficient by 23.5% and 35.1%, whereas phosphorus intake was deficient by 33.2% and 56.2% in cows and buffaloes, respectively. Feeding a balanced ration increased (P < 0.05) average daily milk production by 6.7% and 7.6%, whereas cost of production decreased by 13.7% and 9.9% in cows and buffaloes, respectively. Fat-corrected milk increased from 9.1 to 9.8 kg/cow.day and from 6.9 to 7.7 kg/buffalo.day. Intestinal flow of microbial N improved significantly by 25.5% and 26.7% in cows and buffaloes, respectively. Balanced feeding reduced CH4 emissions (g/kg milk yield) by 17.3% (P < 0.05) in cows and 19.5% (P < 0.01) in buffaloes. The present study indicates that feeding a balanced ration improves milk production and microbial N supply, and reduces CH4 emissions in field animals.

scholarly journals Effect of tannin-containing hays on enteric methane emissions and nitrogen partitioning in beef cattle1

2019 ◽  
Vol 97 (8) ◽  
pp. 3286-3299 ◽  
Author(s):  
Elizabeth K Stewart ◽  
Karen A Beauchemin ◽  
Xin Dai ◽  
Jennifer W MacAdam ◽  
Rachael G Christensen ◽  
...  
Keyword(s):  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Beef Cows ◽  
Nitrogen Partitioning ◽  
Sample Collection ◽  
N Retention ◽  
Treatment Groups ◽  
Ch4 Emissions ◽  
Ch4 Production ◽  
Enteric Methane

AbstractThe objective of this study was to determine whether feeding tannin-containing hays to heifers and mature beef cows influences enteric methane (CH4) emissions and nitrogen (N) excretion relative to feeding traditional legume and grass hays. Fifteen mature beef cows (Exp. 1) and 9 yearling heifers (Exp. 2) were each randomly assigned to treatment groups in an incomplete bock design with 2 periods and 6 types of hays with 3 hays fed each period (n = 5 cows and 3 heifers per treatment). Groups were fed tannin-containing [birdsfoot trefoil (BFT), sainfoin (SAN), small burnet (SML)] or non-tannin-containing [alfalfa (ALF), cicer milkvetch (CMV), meadow bromegrass (MB)] hays. Each period consisted of 14 d of adjustment followed by 5 d of sample collection. Nine cows and 9 heifers were selected for the measurement of enteric CH4 emissions (sulfur hexafluoride tracer gas technique), and excretion of feces and urine, while dry matter intake (DMI) was measured for all animals. The concentration of condensed tannins in SAN and BFT was 2.5 ± 0.50% and 0.6 ± 0.09% of dry matter (DM), respectively, while SML contained hydrolyzable tannins (4.5 ± 0.55% of DM). Cows and heifers fed tannin-containing hays excreted less urinary urea N (g/d; P &lt; 0.001) and showed lower concentrations of blood urea N (mg/dL; P &lt; 0.001) than animals fed ALF or CMV, indicating that tannins led to a shift in route of N excretion from urine to feces. Additionally, cows fed either BFT or CMV showed the greatest percentage of retained N (P &lt; 0.001). Enteric CH4 yield (g/kg of DMI) from heifers (P = 0.089) was greatest for MB, while daily CH4 production (g/d) from heifers (P = 0.054) was least for SML. However, digestibility of crude protein was reduced for cows (P &lt; 0.001) and heifers (P &lt; 0.001) consuming SML. The results suggest that tannin-containing hays have the potential to reduce urinary urea N excretion, increase N retention, and reduce enteric CH4 emissions from beef cattle. The non-bloating tannin-free legume CMV may also reduce environmental impacts relative to ALF and MB hays by reducing N excretion in urine and increasing N retention.

Modelling enteric methane abatement from earlier mating of dairy heifers in subtropical Australia by improving diet quality

2016 ◽  
Vol 56 (3) ◽  
pp. 565 ◽  
Author(s):  
K. M. Christie ◽  
M. T. Harrison ◽  
L. M. Trevaskis ◽  
R. P. Rawnsley ◽  
R. J. Eckard
Keyword(s):  
Carbon Dioxide ◽  
Milk Production ◽  
Nutritive Value ◽  
Northern Australia ◽  
Dynamic Approach ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Enteric Methane ◽  
Metabolisable Energy ◽  
Carbon Dioxide Equivalents

Milking cows typically dominate dairy farm greenhouse gas (GHG) emissions, but replacement heifers also contribute to farm emissions and can increase the emission intensity of milk production. In northern Australia, heifers generally graze poorer-quality subtropical pastures and in the absence of energy-dense supplementary feed during periods of low pasture growth, liveweight (LW) gain can be restricted. This modelling study examined the time required and enteric methane (CH4) emissions produced in raising dairy heifers to a target LW for first mating by feeding a diet assuming either constant (static) or variable (dynamic) nutritive values. Using a static approach (Australian Feeding Standards methodology), and assuming a target mating LW of 360 kg, growing heifers reached their target LW at ~18 months of age while consuming C4 grasses with a constant metabolisable energy content of 9.5 MJ/kg dry matter (DM) or 11 months of age on a diet of 11.0 MJ/kg DM. Enteric CH4 emissions were 1.2 and 0.8 t of carbon dioxide equivalents/heifer over the 18- and 11-month periods, respectively. To explore the extent with which climatic conditions influence seasonal pasture availability and nutritive value with a dynamic approach, we used a whole-farm biophysical model (SGS pasture model) to simulate diets with mean metabolisable energy values of 9.5 and 10.9 MJ/ kg DM. On average (±s.d.), heifers required 22 ± 4 and 17 ± 1 months, respectively, to reach target LW, with cumulative enteric CH4 emissions of 1.22 ± 0.20 and 0.72 ± 0.04 t carbon dioxide equivalents, respectively. The dynamic approach resulted in slower LW gain due to the variable nutritive value of the diet throughout the year, resulting in seasonal periods of LW plateauing or decline. Maintaining heifers on high-quality diets in subtropical northern Australia should result in increased daily LW gain, lower enteric CH4 emissions to mating LW and earlier calving. Together, these factors reduce their lifetime emission intensity of milk production.

scholarly journals Human development, greenhouse gas emissions and sub-national mitigation burdens: a Brazilian perspective

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Geanderson Ambrósio ◽  
Dênis Antônio Da Cunha ◽  
Marcel Viana Pires ◽  
Luis Costa ◽  
Raiza Moniz Faria ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Human Development ◽  
Socioeconomic Development ◽  
National Level ◽  
Green Economy ◽  
Ghg Mitigation ◽  
The Sustainable Development ◽  
National Human ◽  
Development Goals ◽  
Carbon Dioxide Equivalent

AbstractInternational frameworks for greenhouse gas (GHG) mitigation usually disregard country-specific inequalities for the allocation of mitigation burdens. This may hinder low developed regions in a country from achieving development in a socioeconomic perspective, such as the Sustainable Development Goals (SDGs) of eradicating poverty (SDG1) and hunger (SDG2). We use observed data (1991–2010) of carbon dioxide equivalent (CO2eq) emissions and a sub-national human development index (MicroHDI, range [0, 1]) for Brazilian microregions to design a framework where regional mitigation burdens are proportional to the MicroHDI, without compromising national mitigation pledges. According to our results, the less developed Brazilian regions have not been basing their development in emission-intensive activities; instead, the most developed regions have. Between 2011 and 2050, Brazilian cumulative emissions from the sectors most correlated with MicroHDI are expected to be 325 Gt CO2eq, of which only 50 Gt are associated with regions of MicroHDI < 0.8. Assuming a national GHG mitigation target of 56.5% in 2050 over 2010 (consistent with limiting global warming to 2 ºC), Brazil would emit 190 Gt CO2eq instead of 325 Gt and the 135 Gt reduction is only accounted for by regions after reaching MicroHDI ≥ 0.8. Allocating environmental restrictions to the high-developed regions leaves ground for the least developed ones to pursue development with fewer restrictions. Our heterogeneous framework represents a fairer allocation of mitigation burdens which could be implemented under the concepts of green economy. This work could be an international reference for addressing both environmental and socioeconomic development in developing countries at sub-national level as emphasized by the SDGs.

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