Antimethanogenic plants for grazing systems

Durmic, Z. (UWA)Revell, D., Ramírez-Restrepo, C. (CSIRO)

Moate, P. (DPI Vic)Ghamkhar, K., Vercoe, P. (UWA)

Why do herbivores produce GHG?

CelluloseMeat, milk

Herbivores have evolved to consume large quantities of plants and can transform poor quality food (grass) into high quality products (meat and milk).

FoodEnergy

Fermentation

MethaneCO2

Methane emissions from livestock

• mechanism of removing hydrogen from the rumen

H2H2

H2H2

H2

CO2

CH4H2O

H2O

Substrate

Fermentation

VFA (energy)

CO2 +4H2

CH4 + 2H2O

Methane emissions from livestock

Methane emissions from livestock

Cow Sheep

CH4 per day200-300L 20-30L

CH4 head/year 100 kg 8 kg

Reducing methane from livestock

• dietary, i. e. increasing feed quality (grain)

Reducing methane from livestock

• dietary, i. e. increasing feed quality (grain) =

expensive, impact on the environment

Reducing methane from livestock

• dietary, i. e. increasing feed quality (grain)

• feed supplements (i.e. antibiotics)

Reducing methane from livestock

• dietary, i. e. increasing feed quality (grain)

• feed supplements (i.e. antibiotics) = antibiotic

resistance, becoming ineffective

Reducing methane from livestock

• dietary, i. e. increasing feed quality

• feed supplements (i.e. antibiotics)

• vaccine?

Reducing methane from livestock

• dietary, i. e. increasing feed quality

• feed supplements (i.e. antibiotics)

• vaccine = ineffective, expensive, side-effects

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

Some novel, safer, long-term and more effective

approaches:

• breeding for low-methane animals

• ‘bioactive’ plants and secondary compounds

• novel and natural feed additives

Reducing methane from livestock – novel approaches

• Methane is produced by microbes

• Plant contain secondary compounds

(PSC)

• Many ‘bioactvie’ (antimicrobial)

• I.e. tannins - antimethanogenic

‘Bioactive’ plants may affect methane output?

• Part of a normal animal diet

• Our production systems are forage-based

• Great plant diversity in Australia

• Harsh environment = more PSC = more ‘bioactive’

Why AM plants may be a solution for Australia?

Why AM plants may be a solution for Australia?

500 plants

6 active

100 plants

30 active

no reduction5-25% reduction>25% reduction

Plant antimethanogenic potential – EU vs AU

EU ‘Replace’ AU ‘Enrich’

• can help transform landscapes

• provide out of season fodder, provide shelter for the

animals

• retain water, absorb salt, prevent soil erosion, wind

break

Why plants may be a solution for Australia?

Other benefits:

UWA Research farm30 Jan 2011

UWA Research farm31 Jan 2011

UWA Research farm31 Jan 2011

Monarto (SA) Badgingarra (WA)

‘BEFORE’

Why plants may be a solution for Australia?

Monarto (SA) Badgingarra (WA)

AFTER

Why plants may be a solution for Australia?

Projects

2005-2008ENRICH 1 - Multi-purpose ‘healthy’ grazing systems using perennial shrubs2008-2010ENRICH 2 - Building functional and resilient systems with forage shrubs

2009-2011Antimethanogenic bioactivity of Australian plants for grazing systems

2011 - 2015Exploiting the subterranean clover (Trifolium subterraneum L.) genome to meet future challenges for Australian livestock industries - climate change mitigation and ruminant health.

2010Variation for in  vitro methane production in pasture legumes with particular focus on subterranean clover.

2009-2012Using bioactive secondary plant compounds for improving health and function in grazing ruminants

Approach and methodology

Arid (sheep)Legumes (sheep)

Pastures (beef)

Tropical pastures (beef)

Novel pastures (dairy)Arid (sheep)

Approach and methodology

Collect plant Test in vitro Identify candidatesmaterial

Approach and methodology

Expand the screening

Confirm in vivo

Identify PSC

Variability

Management

Results

Native shrubs(WA and SA, sheep)

• varied methanogenic potential (4 mL/g – 84 mL/g DM)

• plants with beneficial profiles identified

10 20 30 40 50 60 70 80 90 100 110 1200

10

20

30

40

50

60

70

80

90

Gas pressure (kPa)

CH

4 (

mL/

g D

M)

Durmic et al., 2010

Oaten chaff

Legumes and grasses (WA, sheep)

• varied methanogenic potential (4 mL/g – 51 mL/g DM)

L.p. B.b. O.s. B.p M.p. T.p. L.r T.s.W. L.c. T.s. M.s. O.c. T.r. T.s.D.0

10

20

30

40

50

60

Plant

CH

4 (

mL/

g D

M)

Lucerne

Tropical forages (North QLD, beef)

• varied methanogenic potential (18 mL/g – 60 mL/g DM)

Callia

ndra

cal

othy

rsus

Desm

anth

us le

ptop

hillu

s

Desm

anth

us b

icor

nutu

s

Desm

anth

us v

irgat

us

Leuc

aena

leuc

ocep

hala

Bagas

se 1

Desm

anth

us v

irgat

us (M

)

Mitc

hell

gras

s 1

Spea

rgra

ss 2

Centr

osem

a m

olle

Seba

nia

sesb

an

Desm

odiu

m h

eter

ophy

llum

Spea

rgra

ss 1

Buffel

3

Glyci

ne ta

baci

na

Burga

ndy

Bean

Angel

ton

gras

s

Cham

aecr

ista

Rot

uind

ifolia

Clitor

ia te

rnat

ea

Glyric

idiu

m s

epic

um

Mitc

hell

gras

s 2

Rhode

s2

Arach

is p

into

i (A)

Styl

osan

tes

seab

rana

Arach

is p

into

i

Styl

osan

tes

scab

ra

Vigna

lace

olat

a

Arach

is p

arag

uarie

nsis

Centr

osem

a pa

scuo

rum

Rhode

s3

Bagas

se 2

Styl

o fin

e st

em

Rhode

s Lo

w

Styl

o s

p.

Dolic

hos

Bisse

t 2

Ryegr

ass

Luce

rne

2

Butte

rfly

Pea

Whe

aten

str

aw

Buffel

2

Bisse

t 1

Rhode

s 00

Luce

rne

1

Styl

osan

tes

ham

ata

Pang

ola

2

Rhode

s1

Buffel

1

Leuc

aena

Rhode

s Hig

h

Seca

sty

lo

Pang

ola

1

Cattin

gga

Styl

o

0

10

20

30

40

50

60

70

Plant sample

CH

4 (

mL/

g D

M)

Lucerne

Novel forages (Vic, dairy)

• varied methanogenic potential (36 -57 mL/g DM)

Broco

lli (B

)

Broco

lli (P

)

Chico

ry 1

Chico

ry 2

Chico

ry 3

Clove

r 1

Clove

r 2

Hunte

r

Plan

tain

Turn

ip b

ulb

1

Turn

ip b

ulb

2

Turn

ip le

af 1

Turn

p le

af 2

Win

fred

leaf

1

Win

fred

stem

1

Win

fred

who

le 1

Win

fred

who

le 2

0

10

20

30

40

50

60

70

Forage

CH

4 (

mL/g

DM

)

* * **

*

Lucerne

Novel additives - DHA

• DHA caused small, but significant reduction in methanogenic potential, but

only when mixed with a concentrate diet

Forage DHA/forage Pellet DHA/pellet DHA(o)/pellet0

10

20

30

40

50

60

70

Treatment

CH

4 (

mL/

g D

M) *

Moving towards in vivo

Artificial rumen

Animal house

Paddock-scale

Confirmation

Dose

Persistence

Effect on microbesWhich ones?Static/cidal?

Effect on vital functions

Results from the artificial rumen

• Methane reduced immediately with addition of 25%

EG

• Gas production was unaffected

• Effect persisted over 8 days

7 8 9 10 11 12 13 14 150

2

4

6

8

10

12

14

16

ControlEG 25%

Day

CH

4 (

%)

Moving towards in vivo

Artificial rumen

Animal house

Paddock-scale

Confirmation

Dose

Persistence

Effect on microbesWhich ones?Static/cidal?

Effect on vital functions

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

Partners

Antimethanogenic plants

for grazing systems

More info:zoey.durmic@uwa.edu.au