By Gift Briton
Although science has proven that ruminant livestock, including cattle, sheep, camels and goats produce methane which contribute to climate change and that they are the main source of greenhouse gas (GHG) emissions in most African countries, uncertainties still exist due to limited local data.
Claudia Arndt, Senior Scientist at International Livestock Research Institute (ILRI) said noting that there is little research and few action measurements from Africa to put some real numbers on emissions.
To close this information gap, ILRI researchers conducted laboratory and field-based studies to generate data on GHG emissions from livestock that is representative for African livestock systems.
This data will be sent to the Intergovernmental Panel on Climate Change (IPCC) inventories for African governments to use in guiding their emissions’ reduction priorities.
The research found that methane emissions from cattle were 15% lower than previously reported, which could indicate that cattle in Africa have a lower impact on the climate than expected. On the other hand, sheep and goats had higher methane emissions than previously reported for Africa.
Manure from livestock also contribute to climate change by releasing both methane and nitrous oxide.
The researchers found that nitrous oxide emissions were 29% lower than prior estimates for dung and urine deposited during grazing. Furthermore, manure applied as fertilizer had 97% lower nitrous oxide emissions compared to prior estimates.
“We are trying to make GHG emission more accurate and also helping African nations to move from the default data from the IPCC guidelines to country specific inventories that are more accurate to allow tracking of the mitigation progress,” Arndt adds.
Reducing Methane Emissions While Still Ensuring Productivity
To promote climate-smart agriculture that increase productivity and improve climate change adaptation and mitigation, ILRI conducted an experiment study to establish how different animal feed, breed, and health affects greenhouse gas emissions.
To measure methane emissions from an animal, the animal is put in a respiration chamber which is an air-tight box with continuous inflow and outflow of air. It is put in this box for 22 hours and is given different types of feed during this period. The concentration of greenhouse gas is measured at the inflow and outflow of the chamber and the difference is the emissions that the animal is producing.
“We put the animal in the chamber of 22 hours because that is approximately how long it takes for the whole digestion process to take place,” she notes.
The study found that feed intake is directly correlated to methane emissions; the more feed the animal consume, the more methane it produces.
Also, animals that do not receive enough feed produce more methane per unit of feed. This is because whatever they eat stays in the stomach for a long time giving the microorganisms that produce methane more time to do so.
“It is not efficient to have a hungry animal. In many systems, animals are usually hungry during the dry season and this increases their emissions footprints,” Arndt says.
Moreover, animals affected by parasites were also found to be less productive and produced more emissions and the bigger the animal, the more methane it produced.
According to Arndt, one of the key interventions to reduce methane emissions from livestock while still ensuring that the animal is productive is by optimally feeding it through increasing food availability and quality.
The study found that quality feed improves productivity and reduce emissions. Feed such legumes, increased milk production and reduced emissions from the animal because legumes contain a compound that microorganisms that produces methane in the stomach do not like.
Arndt urges that farmers should focus on keeping few cows that are more productive and produces less emissions than keeping many cows with the same productivity level but emitting more methane.
