Ruminant Methane Emissions Reductions in Developing Countries
RuMeth International’s projects utilize methodology that is based on our pioneering work with ruminant methane efficiency in developing countries. This methodology is built on the ruminant methane assessment methodologies for the Inter-governmental Panel on Climate Change (IPCC) Tier II livestock evaluation.
Ruminant Methane as a Greenhouse Gas
Domesticated ruminant animals such as buffalo, cattle, goats and sheep are the largest source of anthropogenic methane, annually contributing an estimated 28% of global methane production. Methane is a naturally occurring by-product of the ruminant digestive tract. The rumen digestive tract is made up of four separate stomachs, the rumen, the reticulum, the abomasum and the omasum. The largest (120 – 160 litre) and most important of these is the rumen. The rumen functions as a fermentation vessel and allows the animal to consume and draw nutrients from plant material that would be indigestible by humans. The rumen contains large populations of microorganisms which break down the plant material. Methane is given off by the microorganisms and expelled from the animal through eructation.
Generally speaking, the level of methane production from the rumen is inversely related to the quantity (energy value) and quality (digestibility) of the feed an animal consumes. As the amount of feed consumed increases, the energy available to be converted into methane also increases. However, as the digestibility of the feed increases, the percentage of the energy that is converted to methane decreases. For this reason, methane production is calculated as a percentage of the energy consumed. In a feed ration that is highly digestible, it would be expected that 6% of the energy would be converted to methane. As the digestibility of a ration decreases, the percentage of energy converted to methane increases to a point as high as 9% 1.
In the developed countries of the world, ruminant livestock are kept in well managed production systems and generally fed diets that are very high in digestibility and nutrients. The result is very efficient production (milk or meat) relative to the amount of methane emitted. Unfortunately, ruminants in developing countries are kept on diets that are low in both digestibility and nutrient content. This leads not only to greatly increased methane emissions, but also very diminished productivity relative to the animals’ genetic potential. This inefficient productivity has global implications. Food and Agriculture Statistics (FAO) indicate that developing nations account for more than 75% of the world's cattle/buffalo population, yet account for only 35% of the livestock products produced globally.
The explanation for this is that developing countries rely more on an increase in the number of animals to achieve a greater quantity of animal products rather than on improving productivity per animal. In these countries, livestock production is primarily in the hands of small-scale producers who have traditionally been overlooked in the dissemination of technologies which would promote increased per animal productivity. This sub-standard productivity results in a very high cost in terms of methane emissions per unit of product, compared with properly managed livestock. As developing countries’ human populations expand, and thus the demand for milk and meat, methane emissions from livestock also greatly increase.
RuMeth International’s Approach
The logical solution therefore, is to improve the per animal productivity of the existing herd. This is the approach targeted by RuMeth International, under the rational that if the barriers to enhancing per animal productivity can be diminished, then a larger percentage of the milk/meat demand can be meet by fewer numbers of animals each with a higher production efficiency. In this manner, there will be more of an optimization of the emissions of the gas relative to the production of the end used product.
From the U.S. EPA website;
“Since methane represents a loss of carbon from the rumen and therefore an unproductive use of dietary energy, scientists have been looking for ways to suppress its production. The most promising approach for reducing methane emissions from livestock is by improving the productivity and efficiency of livestock production. Greater efficiency of livestock production can increase profitability and be good for the environment at the same time. This general approach has been demonstrated by the U.S. dairy industry over the past several decades as milk production increased and methane emissions decreased. Nutritional and genetic improvements are mainly responsible for making modern U.S. dairy cows more productive.” 2
Most cattle in developing countries are kept by small-scale producers and without the benefit of improved management practices. This lack of innovation results in the livestock yielding far less than their genetic potential. Generally speaking, these animals are fed either native grasses or agricultural by-products, which are comparatively low in digestibility and thus result in greatly decreased rumen efficiency. These diets differ substantially from those of animals in developed countries, with caloric intake levels that barely fulfill maintenance requirements. The low level of production per livestock unit is the result of seasonal variations in available feedstuffs and output, lack of improved production practices at the farm level, limited feed and/or mineral supplementation, and limited distribution and marketing channels for feed products. Animals are therefore less productive than their genetic potential. Consequently, milk/meat production, animal power, and economic return to the producers are comparatively low. Substantial productivity improvements and methane emissions reductions are possible when the digestibility and the efficiency of utilization of these feeds are increased.
As the human population of a developing country increases and the economy continues to develop, there is a growing demand for milk/meat. Because of the low productivity per animal unit, a larger than necessary bovine population will be needed to keep pace with the larger number of people and the increase in demand per capita due to rising incomes. Meeting this expanded demand will require an increasing number of animals and/or a more productive national herd. From a global environmental perspective, increasing per animal productivity is preferred to expansion of the national herd because it results in significantly less ruminant methane for any given level of consumption of livestock products.
The approach targeted by RuMeth International is as follows: Introduce a feed supplement technology that naturally promotes more efficient digestion. More efficient digestions results in a decrease in ruminant methane emissions, while simultaneously increasing animal productivity. This approach allows the country to meet its increasing animal products demand in a “cleaner” manner3 . By raising per animal productivity, a greater amount of animal products can be provided to the human population at a much reduced cost in terms of methane.
From the Greenhouse Gas Online website;
“The best studied and applied methane reduction strategy has been that of altering the feed composition, either to reduce the percentage which is converted into methane or to improve the meat and milk yield. Improvements in the overall quality of animal feed may allow meat and dairy production to be maintained at the same level with fewer animals and so less total methane emission.” 4
1 Options for Reducing Methane Emissions Internationally, Volume 1:Technological Options for Reducing Methane Emissions, US Environmental Protection Agency, Washington D.C. Report to Congress. 1993.Pp. 6-1.
3 For a more detailed discussion, see “Ruminant Livestock,” Chapter Five of Options for Reducing Methane Emissions Internationally, Volume II: International Opportunities for Reducing Methane Emissions. Global Change Division, US Environmental Protection Agency, Washington D.C. April 1993.