Antimethanogenic plants for grazing systems

1. Antimethanogenic plants for grazing systems Durmic, Z. (UWA) Revell, D., Ramírez-Restrepo, C. (CSIRO) Moate, P. (DPI Vic) Ghamkhar, K., Vercoe, P. (UWA)

2. Why do herbivores produce GHG? Herbivores have evolved to consume large quantities of plants and can transform poor quality food (grass) into high quality products (meat and milk). Cellulose Meat, milk

3. Methane emissions from livestock FoodEnergy Methane CO2 Fermentation

4. Methane emissions from livestock • mechanism of removing hydrogen from the rumen Substrate Fermentation VFA (energy) CO2 +4H2 CH4 + 2H2O CO2 H2 H2 H2 H2 CH4 H2 H2O H2O

5. Methane emissions from livestock

6. Reducing methane from livestock • dietary, i. e. increasing feed quality (grain)

7. Reducing methane from livestock • dietary, i. e. increasing feed quality (grain) = expensive, impact on the environment

8. Reducing methane from livestock • dietary, i. e. increasing feed quality (grain) • feed supplements (i.e. antibiotics)

9. Reducing methane from livestock • dietary, i. e. increasing feed quality (grain) • feed supplements (i.e. antibiotics) = antibiotic resistance, becoming ineffective

10. Reducing methane from livestock • dietary, i. e. increasing feed quality • feed supplements (i.e. antibiotics) • vaccine?

11. Reducing methane from livestock • dietary, i. e. increasing feed quality • feed supplements (i.e. antibiotics) • vaccine = ineffective, expensive, side-effects

12. Reducing methane from livestock – novel approaches • Some novel, safer, long-term and more effective approaches: • breeding for low-methane animals • ‘bioactive’ plants and secondary compounds • novel and natural feed additives

13. Reducing methane from livestock – novel approaches • Some novel, safer, long-term and more effective approaches: • breeding for low-methane animals • ‘bioactive’ plants and secondary compounds • novel and natural feed additives

14. ‘Bioactive’ plants may affect methane output? • Methane is produced by microbes • Plant contain secondary compounds (PSC) • Many ‘bioactvie’ (antimicrobial) • I.e. tannins - antimethanogenic

15. Why AM plants may be a solution for Australia? • Part of a normal animal diet • Our production systems are forage-based • Great plant diversity in Australia • Harsh environment = more PSC = more ‘bioactive’

16. Why AM plants may be a solution for Australia? Plant antimethanogenic potential – EU vs AU EU ‘Replace’ AU ‘Enrich’ no reduction 5-25% reduction >25% reduction 100 plants 30 active 500 plants 6 active

17. Why plants may be a solution for Australia? Other benefits: • can help transform landscapes • provide out of season fodder, provide shelter for the animals • retain water, absorb salt, prevent soil erosion, wind break

18. UWA Research farm 30 Jan 2011

19. UWA Research farm 31 Jan 2011

20. UWA Research farm 31 Jan 2011

21. Why plants may be a solution for Australia? ‘BEFORE’ Monarto (SA) Badgingarra (WA)

22. Why plants may be a solution for Australia? AFTER Monarto (SA) Badgingarra (WA)

23. Projects 2005-2008 ENRICH 1 - Multi-purpose ‘healthy’ grazing systems using perennial shrubs 2008-2010 ENRICH 2 - Building functional and resilient systems with forage shrubs 2009-2011 Antimethanogenic bioactivity of Australian plants for grazing systems 2010 Variation for in  vitro methane production in pasture legumes with particular focus on subterranean clover. 2009-2012 Using bioactive secondary plant compounds for improving health and function in grazing ruminants 2011 - 2015 Exploiting the subterranean clover (Trifolium subterraneum L.) genome to meet future challenges for Australian livestock industries - climate change mitigation and ruminant health.

24. Approach and methodology Tropical pastures (beef) Arid (sheep) Legumes (sheep) Pastures (beef) Novel pastures (dairy) Arid (sheep)

25. Approach and methodology Collect plant Test in vitro Identify candidates material

26. Approach and methodology Expand the screening Confirm in vivo Identify PSC Variability Management

27. Results

28. Native shrubs(WA and SA, sheep) Oaten chaff • varied methanogenic potential (4 mL/g – 84 mL/g DM) • plants with beneficial profiles identified

29. Legumes and grasses (WA, sheep) • varied methanogenic potential (4 mL/g – 51 mL/g DM)

30. Tropical forages (North QLD, beef) Lucerne • varied methanogenic potential (18 mL/g – 60 mL/g DM)

31. Novel forages (Vic, dairy) • varied methanogenic potential (36 -57 mL/g DM)

32. Novel additives - DHA • DHA caused small, but significant reduction in methanogenic potential, but only when mixed with a concentrate diet *

33. Moving towards in vivo Artificial rumen Animal house Paddock-scale Confirmation Dose Persistence Effect on microbes Which ones? Static/cidal? Effect on vital functions

34. Results from the artificial rumen • Methane reduced immediately with addition of 25% EG • Gas production was unaffected • Effect persisted over 8 days

35. Moving towards in vivo Artificial rumen Animal house Paddock-scale Confirmation Dose Persistence Effect on microbes Which ones? Static/cidal? Effect on vital functions

36. Summary • Variability exists in methanogenic potential amongst forages • Differences can be of 10 to 20 times magnitude, however other factors such as plant nutritive and agronomic value, overall fermentability and effect on animal should be taken into account • Plants that have strong antimethanogenic potential, but are not suitable as fodder, may be part of a mixed diet or developed as an additive • Observation so far are based on in vitro (laboratory) testing, but work is on the way to confirm findings in vivo

37. Partners

38. Antimethanogenic plants for grazing systems More info: zoey.durmic@uwa.edu.au