As the climate crisis intensifies, reducing global greenhouse gas emissions has become an urgent priority that requires immediate and sustained action. Methane, one of the greenhouse gases, is particularly of concern with its strong ability to trap heat in the atmosphere. Animal agriculture is responsible for approximately 12% of global greenhouse gas emissions, with methane from enteric fermentation accounting for the largest proportion. Efforts are being made to reduce greenhouse gas emissions associated with livestock through dietary adjustments, genetics, manure management, grazing practices, and feed additives. Feed additives are ingredients included in the diet that do not directly provide nutrients but are intended to improve or regulate physiological processes such as digestion and growth. To meet our climate goals, we need to start reducing emissions today, and feed additives are one of the most effective strategies for doing so. 

The Role of Feed Additives in Animal Nutrition

Cattle are ruminant animals that naturally produce methane as their bodies break down their food and convert it into energy through a process known as rumen fermentation. Ruminants are unique in their ability to digest forages containing cellulose, a substance that humans are unable to break down. This ability is facilitated by a complex community of microorganisms that live within a compartment of their digestive system called the rumen. These microorganisms help break down the cellulose from plant material, providing essential nutrients to the cattle in exchange for a place to live. Microorganisms in the rumen are collectively referred to as the ruminal microbiome.

One important group of microorganisms within the ruminal microbiome is methanogens, which produce methane as a byproduct through a process known as methanogenesis. Methanogenesis occurs in anaerobic conditions, meaning environments where oxygen is absent or in very low concentrations, such as the rumen. This process does not require a lot of energy, making it highly efficient and easily carried out by methanogens. The methane that is produced eventually travels back up the digestive tract and is belched out into the atmosphere during a process down as rumination. 

Feed additives can be used to alter the ruminal microbiome in ways that disrupt or reduce the process of methanogenesis. By carefully modifying the ruminal microbiome, we can consistently reduce enteric emissions on a daily basis. This can be achieved with relatively small doses, as feed additives account for less than 1% of the animal’s daily feed intake. 

Feed Additives as a Climate Solution

Recent scientific studies indicate that certain feed additives can substantially reduce methane emissions from dairy and beef cattle. Among the most promising are bromoform and 3-nitrooxypropanol (3-NOP), which have been shown to reduce emissions by up to 30-50%. By incorporating feed additives into the daily feed ration, producers can reduce emissions directly from the source each day. Additionally, they can be integrated into existing farming operations with minimal disruption, making them a feasible option for many livestock producers. 

Feed additives used in livestock undergo thorough assessments to ensure they pose no risk to animal health, consumer safety, or the environment. Producers are committed to maintaining the health and productivity of their animals, and as such, significant research has been conducted to determine the types and amounts of additives that are both ethical to administer and that do not negatively impact animal productivity. These assessments verify that the additives do not alter the nutritional quality of meat or milk, meaning they are safe for human consumption. Furthermore, their environmental impact is relatively low, both in terms of production and disposal. 

Incorporating Feed Additives: Extensive vs. Intensive Systems  

Feed additives have shown to be highly effective in intensive systems, operations with high levels of management and inputs, such as a dairy or feedlot. Animals in these systems are fed a daily ration that a feed additive can be easily incorporated into and distributed into accessible feed bunks. 

Feed additives are less effective in extensive systems, operations with lower levels of management and inputs. This primarily includes pasture-based systems, such as cow-calf operations, where animals often roam large acres of land. In these systems, animals are not fed a controlled daily ration, making the consistent administration of feed additives more challenging. There is a need for continued research to explore approaches that could extend the benefits of feed additives to extensive systems, leading to even greater reductions in emissions and further progress toward global climate targets. 

Conclusion

Feed additives are an essential tool in reducing enteric emissions and play a key role in achieving climate goals in agriculture by providing an immediate solution to curbing global methane emissions. These additives provide intensive systems with an immediate approach that is both scalable and feasible to integrate into their current practices. According to the Food and Agriculture Organization (FAO), feed additives are vital for mitigating the environmental impacts of livestock and should be incentivized to encourage producers to adopt. The route to reducing global methane emissions begins with implementing innovative solutions - such as feed additives - if we are to slow global warming while also producing food for a growing population.