Abstract
The methodology provided by the Intergovernmental Panel on Climate Change (IPCC) guidelines is widely used for estimating enteric methane (CH4) production by cattle. No attempt other than the default values in the IPCC Tier 1 has been made for estimating CH4 emission from Hanwoo, a dominant beef species in Korea raised in a unique feeding system. The objective of this study was to compare models for estimating the CH4 emission factor (MEF; kg CH4/head/year) for enteric fermentation in Hanwoo steers. The MEF was estimated based on Korea- and Hanwoo-specific data obtained from the literature using several models. The models include the IPCC Tier 1 (T1), the IPCC Tier 2 method (T2), the IPCC Tier 2 methodology with actual dry matter intake (T2DMI), and the Japanese Tier 3 method (JT3). The JT3 was included due to the similarity in the beef cattle production system between the two countries. Estimated MEF using T2 were 43.4, 33.9, and 36.2 kg CH4/head/year for the growing, finishing, and overall period, respectively. The overall MEF estimated using T2 was 23 % lower than the estimate by T1 (47.0 kg CH4/head/year). There were significant differences in the estimated MEF for enteric fermentation of Hanwoo steers among the methods (P < 0.05). The overall MEF estimated by JT3 was 69.1 kg CH4/head/year, which was significantly higher than the estimates by T2 (36.2 kg) and T2DMI (33.5 kg). The JT3 estimated the highest values in all periods possibly due to overestimation of the conversion ratio of feed energy to CH4. No significant difference was found in the overall MEF of Hanwoo steers between T2 and T2DMI. However, T2DMI estimated 8 % higher and 14 % lower MEF than T2 for the growing and finishing period, respectively, mainly because the T2 significantly over-predicts the gross energy intake of Hanwoo steers at the high level of intake. The IPCC default methods have limitations in their use for a feeding systems in non-western countries, and thus development of a country-specific methodology and parameter estimates for enteric CH4 production is required for Hanwoo and other cattle production systems.
Highlights
Due to an increase in public concern about climate change, greenhouse gas (GHG) emissions have become one of the major issues in all industrial sectors (Lashof and Ahuja 1990; Canadell et al 2007; Meinshausen et al 2009)
The overall methane emission factor (MEF) estimated by Tier 2 method (T2) was 23 % lower than Tier 1 (T1)
The largest discrepancy was observed in the finishing period; the estimated enteric MEF for finishing using Japanese Tier 3 method (JT3) was 115 and 148 % higher than that using T2 and T2DMI, respectively
Summary
Due to an increase in public concern about climate change, greenhouse gas (GHG) emissions have become one of the major issues in all industrial sectors (Lashof and Ahuja 1990; Canadell et al 2007; Meinshausen et al 2009). For the estimation of enteric CH4 production by cattle, methodologies suggested by the Intergovernmental Panel on Climate Change (IPCC) guidelines are widely used. The IPCC guidelines provide methodologies for estimating the enteric CH4 emissions from cattle at three levels of detail from Tier 1 (default values), Tier 2 (includes consideration of diet and energy intake), to Tier 3 (country specific methodology and parameter estimates). The IPCC Tier 2 approach estimates CH4 emissions from enteric fermentation of individual cattle by calculating a CH4 emission factor (MEF, kg CH4/head/year). This is the product of a CH4 conversion factor (MCF; percentage of gross energy [GE] in feed converted into CH4) and daily GE intake (MJ/ head/day). The animal and feed characteristics are used to predict daily GE intake of cattle using equations, while pre-defined default values (0, 3.0, and 6.5 % for calves, feedlot, and the other stages of cattle, respectively) are used for MCF
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
