DOMESTIC OFFSETS INTEGRITY COMMITTEE
C/- DOIC Secretariat
GPO Box 854
CANBERRA ACT 2601
The Hon Yvette D’Ath MP
Parliamentary Secretary for
Climate Change, Industry and Innovation
Parliament House
CANBERRA ACT 2600
Dear Mrs D’Ath
The Domestic Offsets Integrity Committee has considered the following activity proposed
for inclusion on the Positive List under the Carbon Farming Initiative:

Reducing emissions from ruminant livestock by feeding nitrate supplements.
The Committee considers that this proposed activity is suitable for inclusion on the Positive
List for the reasons provided in the Statement of Reasons.
The Committee notes that there is potential for toxicity issues to arise in association with
this activity in certain circumstances. This issue can and should be addressed through any
methodology developed for this activity.
Yours sincerely
AJ Press
Chair
Domestic Offsets Integrity Committee
May 2013
STATEMENT OF REASONS
The Domestic Offsets Integrity Committee considers that the following activity is suitable for
inclusion on the Positive List for the reasons outlined below.
Reducing emissions from ruminant livestock by feeding nitrate supplements.
Background
Nitrates are mineral based supplements and when used as feed supplements for livestock
can be calcium, potassium, or ammonium based. Nitrate supplements allow some microbes
in the rumen to outcompete methane-forming microbes ensuring less methane is
produced1,2,3.
When first introduced into an animal’s diet, or in large quantities, nitrate supplements have
the potential to be toxic, and sometimes fatal. However, several studies have found that
slow introduction over an adaptation period overcomes toxicity risks4. In one study, a 16 day
adaptation period was sufficient to allow the rumen microbes to adjust to nitrates5.
The Committee notes that any methodology for this activity would need to ensure that
projects are carried out in such a way as to ensure there is no detrimental impact on
livestock.
Nitrate supplements can replace the feeding of urea, which promotes methane-forming
microbes. Urea is typically fed to livestock when there is poor quality pasture, for example
during the dry season. Urea affects rumen microbes, allowing feed to be more easily
digested and more feed to be eaten. Urea also has the potential to be toxic. Potential health
effects have been addressed by feeding urea in a lick block, which reduces the amount that
livestock can consume.
Because of the unappealing taste, feeding nitrate supplements may cause livestock to eat
less6. This can be addressed by also feeding the livestock grain. A high carbohydrate feed,
such as grains, can counteract the effects of a reduced feed intake and toxicity if necessary7.
1
J.V. Nolan et al, Effects of dietary nitrate on fermentation, methane production and digesta kinetics in sheep, Animal
Production Science 50:801-806, 2010.
2 R.A. Leng, The potential of feeding nitrate to reduce enteric methane production in ruminants, 2008.
www.penambulbooks.com/Papers%20&%20Presentations.htm
3 L. Li, J. Davis, J. Nolan and R. Hegarty, An initial investigation on rumen fermentation pattern and methane emission of
sheep offered diets containing urea or nitrate as the nitrogen source, Animal Production Science 52(7): 653-658, 2012.
4 R.A. Leng and T.R. Preston, Further considerations of the potential of nitrate as a high affinity electron acceptor to lower
enteric methane production in ruminants, Livestock Research for Rural Development 22 (12), 2010.
5 R.B.A. Hulshof et al, Dietary nitrate supplementation reduces methane emission in beef cattle fed sugarcane-based diets,
Journal of Animal Science, 2012.
6 Hulshof et al, Dietary nitrate supplementation, p.1.
7 S. Robson, Nitrate and nitrite poisoning in livestock, Primefacts: Profitable and sustainable primary industries, 2007,
http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0006/111003/nitrate-and-nitrite-poisoning-in-livestock.pdf, pp2-3.
Reasons for advice
There is clear evidence the use of nitrates reduces methane emissions from livestock.8,9
Studies have shown that supplementing feed with nitrates can reduce methane emissions
from cattle and sheep by more than 20 per cent10. In some cases beef cattle fed a diet
including nitrate were found to have a one third reduction in methane emissions compared
to cattle with feed supplemented by urea or other diets11.
Feeding nitrate supplements to livestock is not common practice. Research identifying the
potential benefits of nitrate feed supplementation is relatively recent and there is a range of
barriers to the uptake of the practice. Products that enable nitrate supplements to be fed to
cattle safely have yet to be commercialised. Farmers are likely to prefer to use urea rather
than nitrates because urea has greater nutritional density, is less costly and easier to
transport. Further, farmers may remain concerned about toxicity notwithstanding evidence
that this can be avoided.
8
C. Grainger and Beauchemin K.A. 2011, Can enteric methane emissions from ruminants be lowered without lowering
their production? Animal Feed Science and Technology, 166-167, 308-320.
9 R.J. Eckard, C.Grainger and C.A.M de Klein, Options for the abatement of methane and nitrous oxide from ruminant
production: A review, Livestock science 130, 2010, 47-56.
10 Leng, Further considerations of the potential of nitrate, 2010.
11 Hulshof et al, Dietary nitrate supplementation, 2012.