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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
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