Mitigation of enteric methane production by ruminants: strategies relevant to New Zealand's pasture-based agricultural systems.

Authors

E N Bermingham, J L Burke, A M Khan, D N Wedlock, P H Janssen, A Jonker

Published in

New Zealand veterinary journal. Pages 1-12. Jul 14, 2026. Epub Jul 14, 2026.

Abstract

The Paris Agreement requires New Zealand to reduce its overall greenhouse gas (GHG) emissions. As a consequence, there is increased interest in reducing enteric methane (CH₄), a major emission source from ruminants such as cattle and sheep. Reducing CH₄ is crucial not only for climate commitments but also to meet sustainability demands from global buyers of NZ's agricultural exports. This review summarises current and future technologies for CH₄ mitigation, focusing specifically on their applicability to pastoral grazing systems.Enteric CH₄ is a natural microbial by-product of feed fermentation in the rumen, formed by methanogenic archaea that use hydrogen and other simple compounds to form CH₄. Current mitigation strategies include chemical inhibitors like 3-nitrooxypropanol (3-NOP), bromoform, and naturally brominated compounds in red seaweed (Asparagopsis spp.). These inhibit methanogenesis but require continuous dosing to be most effective, which is challenging in grazing systems. Feed additives such as probiotics and essential oils can reduce CH₄ by altering the rumen microbiome, although large-scale application faces logistical hurdles. Forage-based approaches such as high-digestibility or tannin-containing plants can reduce methane yield and excreta GHG emissions. While these may represent a more suitable mitigation strategy for NZ's pastoral systems, research is required into improving their broad-scale adoption across a wide range of climates and soil types. Animal breeding offers a permanent option to reduce methane emissions by selecting for traits that lower CH₄ yield or intensity. Early-life interventions during rumen development in calves can potentially induce lasting microbial and physiological changes that reduce methane emissions, although sustained benefits beyond 12 months of age require further investigation.Future solutions include vaccines to produce antibodies targeting methanogens to inhibit methane production, offering a practical and globally applicable mitigation method. Advances in forage genetics, such as tannin-rich clover or lipid-enhanced ryegrass, also show promise but require further research and regulatory changes prior to commercialisation. Concurrently, ongoing improvement of the overall nutritional status of our flocks and herds, to reduce the lifetime GHG footprint, is also required.There is no single mitigation strategy for enteric CH₄ that is universally applicable to NZ's pastoral systems. Achieving NZ's sustainability targets while preserving production efficiency and export competitiveness will require an integrated portfolio of mitigation options. This stackable approach should combine dietary interventions, genetic selection, microbial management, and adaptive management practices to jointly reduce emissions without compromising productivity or market access.

PMID:
42447046
Bibliographic data and abstract were imported from PubMed on 15 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.