Ruminants and climate change
A variety of practices and technologies are currently available that can help reduce greenhouse gas emissions.
In the last decade we have witnessed the transformation of ecosystems by the effect of global climate change, which threatens the well-being of current and future generations. Experts have warned of the excessive accumulation of carbon dioxide in the troposphere and its implications for the global environment. They suggest that substantial cuts in global greenhouse gas emissions are urgently needed to keep global temperatures stable and help mitigate the effects of climate change.
Intensive livestock farming has been controversial for its contribution to the generation of greenhouse gases, however, there are also planned livestock projects that have helped to mitigate greenhouse gas emissions.
Given the consequences of climate change, immediate concerted and collective action is required from all concerned nations, which have even noted a special interest in the need to reduce their ecological footprint in view of its continued increase to ensure food security for society.
With emissions estimated at 7.1 gigatons of carbon dioxide per year, livestock is the third largest source of greenhouse gases.
A variety of practices and technologies are currently available that can help reduce greenhouse gas emissions. However, they are not sufficiently widespread for implementation, even though their application in the livestock sector can significantly reduce emissions.
We can observe that the intensity of emissions varies considerably between production units; this is explained by differences in harvesting practices and supply management. This makes it possible to reduce greenhouse gas emissions if farmers adopt the practices used by producers with the lowest amount of emissions.
The intensity of greenhouse gas emissions is closely related to the efficiency with which producers use their resources.
In livestock production systems, nitrous oxide, methane and carbon dioxide are the three main gases emitted by the sector, representing a loss of nitrogen, energy and organic matter that depresses productivity. Hence, interventions to reduce the gases are based on practices that improve the efficiency of production by the herd.
The most common practices are the use of quality feeds and proper balancing to reduce emissions produced in the animals’ gastrointestinal tract and decrease manure production. Improved genetics and animal health are also important factors that help reduce animal load and thus gas emissions.
As for manure management, practices can be implemented to ensure the recovery and recycling of the nutrients and energy contained in it, i.e. practices that generate different types of energy, including electricity, from the manure.
Another option is the search for sources of supply of low-emission inputs (food and energy, in particular). Carbon sequestration in grasslands can significantly offset emissions, with global estimates of around 0.6 gigatons of carbon dioxide per year. However, before this practice can be implemented, affordable methods to quantify sequestration are needed, as well as a better understanding of the institutional needs and economic viability of this option. A variety of promising technologies, such as food additives, vaccines and genetic screening methods, have great potential for reducing emissions but require further improvement and longer time frames to become viable mitigation options.
To illustrate the mitigation interventions we can apply we have the case of South American specialty beef production, which accounts for 31% of the meat produced by the specialty beef sector in the world, and 17% of global beef and milk production.
This type of specialized production emits around 1 billion tons of carbon dioxide per year and contributes 54% of the emissions caused by the global production of specialized meat and 15% of the emissions produced by the entire livestock sector worldwide.
The ways in which this environmental impact has been mitigated are through the following techniques:
- Improving the quality of pastures. Improved pastures can lead to improvements in forage digestibility and nutrient quality. This correlates with an increase in the growth rates of the animals and in the precocity of the first calving. In addition, improved nutrition can increase fertility rates of cows and reduce mortality rates of calves and mature animals and, consequently, improve animal and herd performance.
- Improved animal health and husbandry. Mainly preventive medicine is related to reducing mortality and increasing growth and fertility rates, improving the performance of the herd.
- Intensive grazing management (carbon sequestration in the soil). The impact of improved grazing management (improved balance between growth and/or availability of forage and grazing) on promoting forage production and soil carbon sequestration is also evaluated.
Greenhouse gas mitigation practices produce environmental and economic benefits and are also intended to increase herd productivity.