Greenhouse in Agriculture - Dietary Supplements for enteric methane abatement
Enteric methane abatement strategies for ruminant production
systems in SE Australia
Expected Outcomes:
Quantified methane abatement strategies for ruminant production
systems in SE Australia consistent with maintaining profitable and
viable livestock production.
Project Objectives:
- Evaluate forages and dietary supplements for methane
mitigation and production impacts
- Evaluate Open Path Tracer methods for measurement of methane
from grazing ruminants
Enteric methane
contributes c. 11% of national greenhouse gas emissions, the
majority of which comes from beef, sheep and dairy cattle. In south
eastern Australia, these three industries mainly occupy relatively
high rainfall, improved pasture zones or feedlots, where dietary and
management interventions for reducing methane are more feasible than
in extensive rangeland zones.
This project is part
of the national Reducing Methane Emissions from Livestock
Program and is funded by DAFF, Meat and Livestock Australia and
Dairy Australia.
Mitigation
This Project builds
on previous research on the impacts of various dietary supplements
on methane mitigation potential for ruminants. An early element of
this Project is to conduct workshop with key members of the
MLA-methane program consortium to establish a national approach to
in vitro screening of various forage options (drawing on
forages evaluated in the 30:30 and EverGraze projects and other
sources), plus a range of dietary supplements (oils/fats, tannin
extracts, forage tannins, nitrates, probiotics, and cellulosic
enzymes) for their methane abatement potential. The team will
continually review and evaluate further options, like the
practicality of sourcing oils from micro-algae, nitrates and
cost-effective sources of tannins and enzymes. All options evaluated
will include an assessment of practical, ethical and cost-effective
means of feeding to grazing ruminants.
From in vitro
screening, promising forages and supplements will then be tested
in vivo using the SF6 method in the field, with the
Open Circuit Respiration Chambers (being more definitive, but also
expensive and limited in treatment combinations) then being the last
step in definitively quantifying the methane abatement potential of
the most promising sub-set of these options. Initial methane
measurements will focus on oils and tannins already identified. The
Project aims to run these various stages of evaluation concurrently,
to ensure that new options are progressing in their evaluation
throughout the life of the Project. Certain oils, tannins, forages
and enzymes have already been identified in prior research, and
these will be evaluated directly using SF6 and chambers,
concurrently with in vitro screening of prospective options.
An integral part of
both field testing with SF6 and measurement in the
chambers will be quantifying production impacts of the various
options, including estimates of Dry Matter intake, milk production,
milk composition and functionality, and/or live weight change.
Initially all evaluations will use dairy cows at Ellinbank, as milk
production is the most sensitive indicator of a production impact
and Ellinbank has over 30 fistulated cows available for essential
rumen sampling. This will assist in keeping experimental periods
shorter (and more cost-effective) than if weight gain or wool
production were used as assessments of production impacts. Where
appropriate (eg. Tannins) full energy and nitrogen balances will
also be conducted in either metabolism stalls or in the chambers, to
understand the impacts on urine and dung N excretion, plus energy
and protein balance.
In partnership with
CSIRO Livestock Industries, the impacts of various forages and
supplements on rumen micro-floral populations will be studied to
understand the mechanism of action of abatement strategies, thus
providing confidence of the longevity/sustainability of enteric
methane abatement options. DNA profiling of rumen microbiota will be
conducted in collaboration with SARDI, to identify differences in
gut/rumen contents in relation to methane emissions from ruminants.
Measurement
This Project will
establish and validate the Open Path FTIR method, including defining
the limitations and appropriate application of this method for use
with animals grazing in paddocks. Further comparison will be made
between methane measured from cattle in planned SF6
experiments and the Open Path FTIR method. The aim of this work will
be to evaluate the Open Path FTIR method as a recognised and
standard method for measuring methane from grazing ruminants. This
proposal includes capital (jointly from VDPI and DAFF) to purchase
and construct a second Open Path FTIR system which is necessary to
conduct this research.
On farm
demonstration
This Project will
work with local and regional groups in collaboration with MLA and
DAFF to contribute to Information Integration and Delivery
(B.CCH.1040) and Demonstration (B.CCH.1030) Projects in the
Reducing Methane Emissions from Livestock Program. Potential
groups include; Bass Coast Landcare, Western Port Greenhouse
Alliance, South West Climate Change Forum and EverGraze. These
regional groups are working with farmers to demonstrate practical
abatement strategies on farm.
Apart from the publication of results in
reports, peer reviewed papers and journals, the Project will use the
existing networks and evaluation processes currently established
within Victoria, plus the information delivery Project established
as part of the Reducing Emissions from Livestock Program.
Start date: 1 April, 2009
Completion date: 1 December, 2011
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