Preview

PDF Pending copyright assessment - Request a copy 491Kb

In Australia, 71% of agricultural greenhouse gas (GHG) emissions are enteric methane (CH4), mostly produced by grazing sheep and cattle. Temperate low CH4 yielding legumes and herbs can mitigate enteric CH4 production, but system-level GHG emissions need to be considered. The aims of the study were to: (1) devise a framework to assess GHG reductions when introducing low CH4 yielding species; (2) assess mechanisms of CH4 reduction in temperate legume and herb species for Australia; (3) use a case study to demonstrate expected changes to system-level GHG emissions with the introduction of low CH4 yielding legumes; and (4) identify knowledge gaps and research priorities. Results demonstrate lowering emissions intensity (kg CO2-equivalent/kg product) is crucial to mitigate GHG emissions, but livestock productivity is also important. Several pasture species have anti-methanogenic properties, but responses often vary considerably. Of the species investigated biserrula (Biserrula pelecinus) has great potential to reduce enteric CH4 emissions, but in a case study its emission intensity was similar to subterranean clover (Trifolium subterraneum) but higher than lucerne (Medicago sativa). We conclude that there are temperate legumes and herbs with anti-methanogenic properties, and/or high productivity that could reduce total CH4 emissions and emissions intensity of ruminant livestock production. There is also great diversity in some plant genotypes that can be exploited, and this will be aided by more detailed understanding of plant secondary compounds associated with CH4 reduction. This review suggests an opportunity to formulate pasture species mixtures to achieve reduced CH4 emissions with greater or equal livestock production.

Item Type:	Refereed Article
Keywords:	bioactive plants, grazing systems, greenhouse gas reduction, herbs, legumes, livestock production, methane emissions, temperate pastures.
Research Division:	Agricultural, Veterinary and Food Sciences
Research Group:	Crop and pasture production
Research Field:	Crop and pasture biochemistry and physiology
Objective Division:	Animal Production and Animal Primary Products
Objective Group:	Environmentally sustainable animal production
Objective Field:	Environmentally sustainable animal production not elsewhere classified
UTAS Author:	Smith, Rowan (Dr Rowan Smith)
ID Code:	155466
Year Published:	2023
Web of Science® Times Cited:	1
Deposited By:	TIA - Research Institute
Deposited On:	2023-02-21
Last Modified:	2023-02-21
Downloads:	0