The Cow of the Future - for a greener dairy
A dairy cow’s rumen allows her to digest the high-fiber feed necessary for milk production, but it also causes her to produce enteric methane gas. Enteric methane is the largest source of greenhouse gas (GHG) emissions associated with milk production. The dairy industry has made great strides in reducing GHG emissions on the farm. The Cow of the Future project seeks scientifically sound, economically viable and socially responsible ways of reducing enteric methane emissions through improvements in dairy cow nutrition, genetics and health. The Cow of the Future project aims to reduce GHG emissions for fluid milk by 600,000 metric tons through the adoption of existing technologies and practices and research into new opportunities.
The Innovation Center for U.S. Dairy has set a goal of reducing enteric methane emissions (per lb. fluid milk) from dairy cattle by 25% by 2020 by implementing the Cow of the Future project.
It was clearly stated by EPA (2005) that “improving livestock productivity so that less methane is emitted per unit of product is the most promising and cost effective technique for reducing emissions in the U.S.”. It is also clear that historical improvements in dairy production have reduced methane emissions per unit of milk substantially (Capper et al., 2009). Implementation of existing technologies and management practices in the U.S. dairy industry along with continued genetic progress in milk yields is expected to result in 10 to 12% reductions of methane emissions per unit of milk over the next decade. To achieve the additional 13 to 15% reduction to reach the overall goal of 25% requires investment in research to identify and develop new strategies and technologies. Conservative estimates suggest that additional reductions of 15 to 30% can be achieved, dependent upon the development of new strategies and technologies and their adoption by the U.S. dairy industry (Figure 1).
Figure 1. Potential reductions in methane per unit of milk (%). Development of new strategies and technologies through research in these areas can significantly reduce methane per unit of fluid milk in U.S.
This Research Priorities document has identified eight major research areas for the development of new strategies and technologies. Focus on these areas will reduce redundancy, improve research efficiency, and increase the overall impact of the research to the dairy industry and to the general public. Several of these areas are not ones that have been widely discussed or recognized to reduce methane emissions from dairy cattle, but they have significant potential to contribute to the goal of reducing methane per unit of milk. This research will also contribute to improvements in dairy profitability, as well as enhancing environmental stewardship and consumer acceptance of dairy products.
Criteria for Future Methane Mitigation Approaches and Technologies
To systematically evaluate proposed research projects regarding their potential for methane reduction and the corresponding impacts on dairy profitability, environmental sustainability, consumer acceptance of dairy production practices and products, and animal health and welfare, the Advisory Group recommends applying the following criteria:
1. Scientific soundness of the approach
2. Potential for productive outcomes of the research project
3. Magnitude of the approach’s potential to reduce enteric methane emissions
4. Economic feasibility of the application/approach, both in terms of the costs of implementing the mitigation approach and avoiding a negative impact on farm profitability.
5. Adoptability or lack of hurdles in applying the mitigation approach on U.S. dairy farms
6. Years to application
7. Other environmental impacts of the approach (water use, land use, nitrogen and phosphorus pollution)
8. Consumer acceptance of the approach
9. Impact on animal health and welfare
10. Originality of the research
Potential Impacts: Benefits and Risks
In addition to reductions in methane emissions, the research in all of the areas has the potential to lead to improvements in dairy profitability, environmental sustainability, consumer acceptance of dairy production practices and products, and animal health and welfare. Because research areas have been identified in this Research Priorities document rather than specific mitigation strategies and technologies that will be the outcomes of such research, only general comments regarding profitability, consumer acceptance, environmental considerations, and animal welfare can be made here. However, these considerations are vitally important in determining which methane mitigation research and development projects should be pursued. Adoption of mitigation strategies by dairy producers will depend on these considerations as well as the feasibility of implementation and regulatory policy. Adoptability and time-to-market should also be addressed in the research and development process.
Of the eight research areas, three areas provide the foundation and integration of knowledge and research tools that will strengthen research efforts in the other five areas. They are: Area 1- Rumen Microbial Genomics and Ecology, Area 7- Development and Refinement of Methane Measurement Techniques, and Area 8- Modelling Efforts to Quantitatively Integrate Knowledge. Consequently, the impact of these areas on methane mitigation and dairy sustainability is indirect and will be manifested by their contribution to the strategies and technologies developed in the other five research areas.
The five Research Priorities areas (Areas 2 through 6) that have direct impacts on methane emissions have moderate (5 to 15%) to high (>15%) reduction potential (figure, p.1). These areas include: Area 2- Rumen Function and Modifiers, Area 3 – Enhancing Feed Quality and Feed Ingredient Usage to Improve Feed Efficiency, Area 4 - Genetic Approaches to Increase Individual Cow Productivity, Area 5- Management Practices to Increase Individual Cow Productivity, and Area 6 – Management of Herd Structure to Reduce Number of Cow-Days of Non-Productive Animals. Mitigation strategies and approaches arising from these areas also have moderate potential to improve dairy profitability through increases in production efficiency at the individual cow or herd level. This would be a win-win for the dairy industry, reducing methane emissions while improving net profits. Of course, the cost of implementing the mitigation approaches will be a factor in profitability.
Additional environmental benefits in reducing methane emissions can occur through some strategies and technologies. If total feed consumption is reduced because of increased production efficiency and fewer animals are required to maintain milk supplies (Areas 3 to 6), less water will be required for growing feed and animal consumption. Water needed to operate dairy facilities may or may not be affected. Alternatives for cooling cows that require less water than current methods will reduce water usage, and opportunities may exist to decrease water use in manure handling systems. Mathematical models that can predict water use on a whole farm or in a geographical region will be needed to quantitatively evaluate the impact of methane mitigation strategies on water use (Area 8). Nitrogen and phosphorus pollution from crop operations and manure handling may be also be affected; these topics are being addressed in the Dairy Farm Smart, Dairy Power, and Biogas Capture and Transport projects sponsored by the Innovation Center for U.S. Dairy. The dairy industry should also receive partial credit for the environmental benefit attributed to biofuels, as the ethanol and biodiesel industries would not be economically viable if the co-products were not consumed by ruminant livestock.
Most methane mitigation strategies and technologies that are currently being proposed and might be developed are expected to have little or no impact on dairy product quality or nutritional value and thus would be acceptable to consumers. The application of some technologies may be more acceptable to consumers than others, i.e. feeding naturally occurring compounds vs. synthetic compounds to modify rumen microbial function (Area 2). Production practices that improve dairy cow health and welfare (Areas 5 and 6) and reduce the environmental impact of dairying (all Areas) will be very acceptable to consumers.
The Research Priorities described in this document have the potential to meet or exceed the Innovation Center’s goal of a 25% reduction in methane emissions, and many of the research areas will complement each other. There are very good scientists at institutions across the U.S. with the capabilities of conducting the needed research. The Cow of the Future project needs to address issues in funding availability, increase opportunities for training future scientists, and promote facilitation of scientific exchange and collaboration. As an additional consideration, outcomes in many of the research areas would benefit the beef industry as well. There is substantial synergy that can be captured with the dairy and beef industries working together.
J.R. Knapp, J.L. Firkins, J.M. Aldrich, R.A. Cady, A.N. Hristov, W.P. Weiss, A.D.G. Wright, and M.D. Welch.
July 2011, Working draft
Read the whole white paper "Research Priorities for Mitigating Enteric Methane Emissions from Dairy" here