A universal equation to predict methane production of forage-fed cattle in Australia

Title
A universal equation to predict methane production of forage-fed cattle in Australia
Publication Date
2016
Author(s)
Charmley, E
Williams, S R O
Moate, P J
Hegarty, Roger
Herd, Robert M
( author )
OrcID: https://orcid.org/0000-0003-4689-5519
Email: rherd3@une.edu.au
UNE Id une-id:rherd3
Oddy, Hutton
( author )
OrcID: https://orcid.org/0000-0003-1783-1049
Email: hoddy2@une.edu.au
UNE Id une-id:hoddy2
Reyenga, P
Staunton, K M
Anderson, A
Hannah, M C
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
CSIRO Publishing
Place of publication
Australia
DOI
10.1071/an15365
UNE publication id
une:20017
Abstract
The methods for estimating methane emissions from cattle as used in the Australian national inventory are based on older data that have now been superseded by a large amount of more recent data. Recent data suggested that the current inventory emissions estimates can be improved. To address this issue, a total of 1034 individual animal records of daily methane production (MP) was used to reassess the relationship between MP and each of dry matter intake (DMI) and gross energy intake (GEI). Data were restricted to trials conducted in the past 10 years using open-circuit respiration chambers, with cattle fed forage-based diets (forage >70%). Results from diets considered to inhibit methanogenesis were omitted from the dataset. Records were obtained from dairy cattle fed temperate forages (220 records), beef cattle fed temperate forages (680 records) and beef cattle fed tropical forages (133 records). Relationships were very similar for all three production categories and single relationships for MP on a DMI or GEI basis were proposed for national inventory purposes. These relationships were MP (g/day) = 20.7 (±0.28) x DMI (kg/day) (R² = 0.92, P < 0.001) and MP (MJ/day) = 0.063 (±0.008)x GEI (MJ/day) (R² = 0.93, P < 0.001). If the revised MP (g/day) approach is used to calculate Australia's national inventory, it will reduce estimates of emissions of forage-fed cattle by 24%. Assuming a global warming potential of 25 for methane, this represents a 12.6 Mt CO₂-e reduction in calculated annual emissions from Australian cattle.
Link
Citation
Animal Production Science, 56(3), p. 169-180
ISSN
1836-5787
1836-0939
Start page
169
End page
180

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