scholarly journals Enteric methane emissions, energy partitioning, and energetic efficiency of zebu beef cattle fed total mixed ration silage

Author(s):  
Sayan Subepang ◽  
Tomoyuki Suzuki ◽  
Thamrongsak Phonbumrung ◽  
Kritapon Sommart
2011 ◽  
Vol 91 (2) ◽  
pp. 305-321 ◽  
Author(s):  
Aklilu Alemu ◽  
K. H. Ominski ◽  
E. Kebreab

Alemu, A. W., Ominski, K. H. and Kebreab, E. 2011. Estimation of enteric methane emissions trends (1990–2008) from Manitoba beef cattle using empirical and mechanistic models. Can. J. Anim. Sci. 91: 305–321. The objective of this study was to estimate and assess trends in enteric methane (CH4) emissions from the Manitoba beef cattle population from the base year of 1990 to 2008 using mathematical models. Two empirical (statistical) models: Intergovernmental Panel on Climate Change (IPCC) Tier 2 and a nonlinear equation (Ellis), and two dynamic mechanistic models: MOLLY (v3) and COWPOLL were used. Beef cattle in Manitoba were categorized in to 29 distinct subcategories based on management practice, physiological status, gender, age and production environment. Data on animal performance, feeding and management practices and feed composition were collected from the literature as well as from provincial and national sources. Estimates of total enteric CH4 production from the Manitoba beef cattle population varied between 0.9 and 2.4 Mt CO2 eq. from 1990 to 2008. Regardless of the type of models used, average CH4 emissions for 2008 were estimated to be 45.2% higher than 1990 levels. More specifically, CH4 emissions tended to increase between 1990 and 1996. Emissions were relatively stable between 1996 and 2002, increased between 2003 and 2005, but declined by 13.2% between 2005 and 2008, following the same trend as that observed in the beef cattle population. Models varied in their estimates of CH4 conversion rate (Ym, percent gross energy intake), emission factor (kg CH4 head−1 yr−1) and CH4 production. Total CH4 production estimates ranged from 1.2 to 2.0 Mt CO2 eq. for IPCC Tier 2, from 0.9 to 1.5 Mt CO2 eq. for Ellis, from 1.3 to 2.1 Mt CO2 eq. for COWPOLL and from 1.5 to 2.4 Mt CO2 eq. for MOLLY. The results indicate that enteric CH4 estimates and emission trends in Manitoba were influenced by the type of model and beef cattle population. As such, it is necessary to use appropriate models for reliable estimates for enteric CH4 inventory. A more robust approach may be to integrate different models by using mechanistic models to estimate regional Ym values, which may then be used as input for the IPCC Tier 2 model.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 380-381
Author(s):  
Isabella Cristina F Maciel ◽  
Fabiano A Barbosa ◽  
Thierry R Tomich ◽  
Ramon C Alvarenga ◽  
Ludhiana R Ferreira ◽  
...  

Abstract Crossbreeding has been used to improve performance in beef cattle; however, the effects of breed composition on methane production, yield and intensity from cattle in a tropical intensive system remain unknown. To assess the impact of breed composition on enteric methane emissions, Nellore (NE; yr 1: BW = 171.5 ± 19.4 kg; n = 10; yr 2: BW = 215.8 ± 32.3 kg, n = 25) and Angus-Nellore crossbred (AN; yr 1: BW = 214.2 ± 26.4 kg, n = 10; yr 2: BW = 242.5 ± 32.2 kg, n = 25) were compared. At trial onset, 10 mo old steers grazed Megathyrsus maximus ‘Mombaça’ in the grazing period (GP) and then were finished in a feedlot (FL) (35:65% corn silage:concentrate diet). Steers (n = 8) from each breed composition were randomly selected in GP and FL to measure CH4 production using a sulfur hexafluoride technique and DMI using titanium dioxide. The NE produced 19% less CH4 than AN in GP (17.21 vs 21.17 kg, P < 0.01), and no difference was observed in FL (22.34 vs 22.67 kg, P > 0.10). However, in FL, NE had greater CH4 intensity (CH4/ADG) compared to AN (122.76 vs 97.49 g/kg, P < 0.01). Furthermore, CH4/carcass weight was greater for NE than AN (0.079 vs 0.067 g/kg CW, P < 0.01). Breed composition did not influence CH4 yield (CH4/DMI) in either phase. The percentage CH4/GEI (Ym) for GP was higher for AN than NE (4.5 vs 3.8%), but lower than the IPCC recommended Ym of 6.5%. In FL, Ym was similar between breed composition (5.0%) and greater than the IPCC Ym of 3%. In our study the introduction of Angus into Nellore has potential to reduce CH4 intensity in tropical climates, resulting in less methane emission per kg beef produced.


2016 ◽  
Vol 99 (6) ◽  
pp. 4374-4383 ◽  
Author(s):  
Aline C. Dall-Orsoletta ◽  
João Gabriel R. Almeida ◽  
Paulo C.F. Carvalho ◽  
Jean V. Savian ◽  
Henrique M.N. Ribeiro-Filho

PLoS ONE ◽  
2019 ◽  
Vol 14 (7) ◽  
pp. e0220247 ◽  
Author(s):  
Isabella Cristina de Faria Maciel ◽  
Fabiano Alvim Barbosa ◽  
Thierry Ribeiro Tomich ◽  
Luiz Gustavo Pereira Ribeiro ◽  
Ramon Costa Alvarenga ◽  
...  

Author(s):  
L R Thompson ◽  
I C F Maciel ◽  
P D R Rodrigues ◽  
K A Cassida ◽  
J E Rowntree

Abstract Greenhouse gas emissions (GHG) from the beef industry is largely attributed to the grazing sector, specifically from beef cattle enteric methane emissions. Therefore, the study objective was to examine how forage diversity impacts forage productivity, nutritive value, animal performance and enteric methane emissions. This study occurred over three consecutive grazing seasons (2018 to 2020) and compared two common Midwest grazing mixtures: 1) a simple, 50:50 alfalfa:orchardgrass mixture (SIMP) and 2) a botanically diverse, cool-season species mixture (COMP). Fifty-six steers and heifers were adapted to an Automated Head Chamber System each year (AHCS; C-Lock Inc., Rapid City, SD) and stratified into treatment groups based on acclimation visitation. Each treatment consisted of four pastures, three 3.2-ha and one 1.6-ha, with 8 and 4 animals each, respectively. Forage production was measured bi-weekly in pre-and post-grazed paddocks, and forage nutritive value was analyzed using near-infrared reflectance spectroscopy (NIRS). Shrunk body weights were taken monthly to determine animal performance. Forage availability did not differ between treatments (P = 0.69) but tended lower in 2018 (P = 0.06; 2.40 t dry matter ha -1) than 2019 (2.92 t dry matter ha -1) and 2020 (P = 0.10; 2.81 t dry matter ha -1). Crude protein was significantly lower for COMP in 2018 compared to SIMP. Forage acid detergent fiber content was significantly lower for the COMP mixture (P = 0.02). The COMP treatment resulted higher dry matter digestibility (IVDMD48) in 2018 and 2019 compared to the SIMP treatment (P < 0.01). Animal performance did not differ between treatments (P > 0.50). There was a tendency for the COMP treatment to have lower enteric CH4 production on a g d -1 basis (P = 0.06), but no difference was observed on an emission intensity basis (g CH4 kg -1 gain; P = 0.56). These results would indicate that adoption of the complex forage mixture would not result in improved forage productivity, animal performance, or reduced emission intensity compared to the simple forage mixture.


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