Special Edition: Environmental footprint reduction initiatives
Experts look to tackle methane emissions in dairy herds in Asia and Africa
In the first of our special editions on feed and livestock ‘greening’ initiatives, we talk to Dr Raghavendra Bhatta, director of the National Institute of Animal Nutrition and Physiology (ICAR) in Bangalore in India about a training course aimed at mitigating the methane emissions associated with dairy farming in Asia and Africa.
The impact of climate change in the Delta regions of South East Asia is hard felt and he said ICAR has received numerous requests for training in methane reduction techniques from researchers in countries under the South Asian Association for Regional Cooperation (SAARC) banner as well as from specialists in African Union countries.
“The Institute is well equipped with state of art laboratories to undertake the research in various areas related to livestock production and climate change and three years ago we started to put together a comprehensive training program.
Our education seminar in August is designed with researchers from developing regions in mind. Experts from the UN’s Food and Agriculture Organization (FAO) and New Zealand’s Global Research Alliance will lend their expertise to proceedings.
Ultimately, the workshops are aimed at capacity building so that, on completion of the course, the participants will go back into the field and train others or drum up public funding to initiate projects with the objective of increasing dairy cattle productivity while limiting methane output,” said Dr Bhatta.
GHG emissions
Methane is the second major source of greenhouse gas emissions (GHG) after CO2 and it is 23 times more potent than CO2. Enteric methane is produced in livestock as a result of microbial fermentation of feed components by rumen microbes.
“In addition to the greenhouse effect of methane, it also represents a loss of 8 to 12% of the gross energy of feed consumed by the animals, thus being one of its most important inefficiencies in ruminant production system,” noted Dr Bhatta.
The most effective approach in relation to limiting GHC production by ruminants, he said, is to increase the efficiency of livestock production as well as producing more from fewer animals.
“It is also important to emphasize that it is the rate of methane production per unit of product produced over a life time which is important in identifying where it is possible to make major reductions in methane emissions, rather than simply expressing methane per head or per animal,” said the Bangalore based expert.
The ICAR’s course involves both theoretical seminars and practical demonstrations regarding strategies to mitigate GHG emissions, primarily in the dairy sector.
“It will include workshops on methane emissions measurement using in vitro and in vivo techniques, breeding approaches, molecular techniques for the identification, analysis and quantification of rumen archaea, modelling to help tackle climate change and feed based strategies to control enteric methane emissions.
We will also address measures to counter the multiple stress factors that dairy herds in the Delta regions face from the obvious heat stress to walking stress as a result of the long distances involved in extensive rearing to nutrient stress due to the lack of quality and quantity of biomass – all of which negatively impact yields, feed intake and growth and therefore can increase the methane load,” said Dr Bhatta.
Feeding strategies
Various GHG mitigation strategies in dairy cattle, he said, including the manipulation of the rumen microbial ecosystem, the feeding of plants containing secondary metabolites, alternate hydrogen sinks, the use of complete feeding blocks over conventional feeding methods, ration balancing and manure management.
“We have seen, for example, that the supplementation of ruminant feed with the optimal dosage of tannins from medicinal and aromatic plant leaves, or saponins or essential oils can help control methanogenesis.
A dosage rate of somewhere between 2.5 to 4% of tannins in dairy cattle feed can result in a reduction in methane emissions by around 15 to 20% without an adverse effect on productivity or rumen fermentation,” said Dr Bhatta.
He said a program, like the one developed by the National Dairy Development Board (NDDB) of India in which milk producers are advised to balance the ration of their lactating animals in a cost effective manner, using locally available feed resources and area-specific mineral mixtures, can not only improve animal productivity but can also led to reduction in methane emission per liter of milk by 10 to 15%.
“Decreasing methane emissions by such percentage terms would stabilize atmospheric methane at its present level and is a realistic objective,” he said.
He added that to get farmers in India, for example, incentivized to get on board with environment targeted initiatives the better approach is to talk about yield increases that can be achieved from incorporating new feeding methods rather than how climate change goals can be met. “Some of those dietary approaches we advocate can involve yield increases of two liters per dairy cow.”
Vaccine R&D
The ICAR has also been investigating the potential of vaccines to abate methane production in India. “We have managed to isolate methanogens from buffalo and we are about a year or two away from producing a vaccine targeting those,” said Dr Bhatta.
He noted also that there are lots of uncertainties in GHG estimates from the livestock sector in India.
Under the ICAR’s Outreach Project on Methane, a common protocol has been developed and followed at seven collaborating centers, he said, in an effort to develop an authentic database on the methane production potential (MPP) of various feeds and diet combinations using an in vitro gas production test and validated using in vivo studies.
And a pilot scale a model is being developed to estimate the enteric methane emission from the state of Karnataka, taking into account the livestock census, the feeding regime and the MPP, said Dr Bhatta.
