Sustainability, defined by the United Nations as “meeting the needs of the present without compromising the ability of future generations to meet their own needs,” has certainly taken many nuances as discussions have evolved toward initiatives in the livestock production sector. We are setting unique goals to include reduction of carbon footprint and environmental impact through changes in farming practices, feed and ingredient sourcing, improvement in manure management and reduction of enteric methane by dairy cows. The latter, a much more recent strategy, relies on the use of feed additives to affect aspects of animal physiology.
When we look at a livestock production system such as a dairy farm, we can see intersections of sustainability working synergistically toward a responsible and viable business model. In dairy cattle, enteric methane emissions applied and deposited manure and feed accounts for roughly 47%, 17% and 10% of the respective CO2 equivalent emissions. A dairy farm is a complex ecosystem where the farm and farming practices, animals (and many rumen microorganisms) and humans, crop and feed, water and waste, manure and milk, among many others, overlap and coexist. Consequently, the ultimate result of these interactions is what leads to the struggles or success of that operation. However, a single strategy is not enough to address all climate change needs. Therefore, any sustainable practice focused on just one of these many areas of a dairy production system is more of an efficiency improvement and not a whole-farm sustainability initiative.
With a holistic sustainability approach, the farm, animals, workers, environment, community, business owners and many others are all important coefficients to reach sustainability goals. Operational and personnel challenges to maintaining the day-to-day dairy activities may have a potential impact on the marketing and supply of a high-value protein product (such as milk, in this example), which could have consequences reaching into the consumer goods supply chain and within local communities. Environmental initiatives in this space must account for all these waves of potential impacts when implemented.
Dairy producers have shown tremendous leadership throughout the many challenges the industry has faced in the past. Considering the current pressures for greenhouse gas (GHG) mitigation, dairy producers are empowered with knowledge and support to achieve such a task. Many initiatives are already paying dividends, such as shown improvements in GHG mitigation using methane digester systems.
Additional and new approaches are also needed to meet the industry’s sustainability goals, including improvement in farming practices such as reduced and no tillage, sourcing of feed ingredients favoring ingredients that require fewer transportation inputs, limiting farming inputs such as water and natural gas and implementing alternative energy sources (for example, solar), improvements in animal and husbandry management such as reduction of dry cows or replacement heifers, as well as the use of feed additives with ruminal effects shown to decrease the amount of enteric methane released in the atmosphere. Science-based feed additives can help target a reduction in enteric methane synthesis through pathways of methanogenesis inhibition, deviating hydrogen ions to different sinks or modifying rumen fermentation to favor less methane production.
Recently, there have been advancements in technologies to estimate carbon intensity (CI) at the farm level. These are becoming important tools for dairy farmers to understand current levels in regard to their enterprises' sustainability and carbon footprint goals. These models take into consideration many variables within larger categories of animals like housing, feeding, manure management, production, etc. The tools consider the entire dairy enterprise’s carbon footprint intensity – number of animals in production and animals per life stage, tonnage of feed consumed, manure management strategy, annual animals to market and production, feed ingredients and sourcing, diet composition, etc.
For example, an average U.S. dairy farm can adopt nutritional strategies to improve its annual milk production by adding a feed additive and reduce its CI value, mostly related to the improvements in production efficiency and better utilization of resources. The same farm could also take it a step further and target supplementation with a specific enteric methane-reducing additive, further reducing its CI level. Small adjustments in feeding strategies can make significant progress toward sustainability goals, demonstrating the importance of a whole-farm carbon footprint assessment in the decision-making process.
Addressing dairy sustainability goals through a comprehensive and holistic approach and taking into consideration the entire operation as the active unit mitigating environmental impact is the ultimate way to ensure all initiatives fulfill the true definition of sustainability.
