Are your cattle causing a greenhouse gas problem? There’s a vaccine for that. Well, maybe.
One of the standouts at the recent Greenhouse Gases and Animal Agriculture (GGAA) conference in Banff was the buzz around work led by Dr. Graeme Attwood of AgResearch in New Zealand.
Attwood’s team, part of New Zealand’s Pastoral Greenhouse Gas Research Consortium (PGGRC), is the first to sequence populations of the rumen microorganisms involved in generating methane. This could mean cutting off livestock methane production at its source, through strategies such as inhibitors and vaccines.
The mystery of the rumen
Cattle may be simple animals but their rumen digestive system is one of the most unique and complex systems in biology. It supports a dense microbial community which can degrade tough plant fibre and turn it into useful nutrients.
With advances in molecular biology, researchers can now peer into the rumen at the molecular level, giving them a much clearer picture of the organisms it contains, how they function and how they can be manipulated. This knowledge provides a basis for strategies toward more efficient livestock production, healthier animals, less waste and higher-quality meat and milk.
Of most interest to researchers at GGAA, it also provides an opportunity to pinpoint and understand the behaviour of the microorganisms involved with methane production as a stepping stone toward strategies that reduce the amount released.
The PGGRC team has now completely sequenced two rumen methanogen genomes, with another five genome-sequencing projects in various stages of progress. Attwood’s primary collaborators, Australia-based researchers led by Dr. Mark Morrison, have also recently obtained draft sequences from two rumen methanogens and are in the process of sequencing another key strain.
Attwood said that their work could eventually lead to designing inhibitors that could be delivered by slow-release capsules, feed supplementation or even vaccines.
Vaccines against diseases of ruminants have a long history of effective and safe use on farm, so an anti-methanogen vaccine would fit easily into current farm practices.
Attwood said these technologies have the potential to be 100 per cent effective. But there are substantial hurdles to overcome before they will be delivered cost-effectively to livestock producers.
One of the challenges is that the diversity of methanogens in the rumen means that any intervention must target them all. Otherwise, any remaining methanogen populations would expand and continue to produce methane.
Technologies would also have to pass the required regulatory hurdles to prove efficacy in the animal and ensure consumer safety, Attwood said.
“I would estimate that it will be five to 10 years before the first products derived from genomics-based investigation are likely to appear. The goal is to drive that progress through PGGRC and associated research programs.”
More information and features on GGAA 2010 are available in this Special Meeting Report at www.ggaa2010.org.
Withadvancesinmolecular biology,researcherscannow peerintotherumenatthe molecularlevel