By Brad Heins, Professor, Dairy
Ruminant livestock are an important source of methane. Enteric fermentation is part of the normal digestive process in ruminants. Decreasing the emissions of enteric methane from dairy cattle is strategic to reduce the carbon footprint of dairy production systems. The U.S. dairy industry has a goal of achieving GHG neutrality as part of the US Dairy’s 2050 Environmental Stewardship Goals. Dairy farmers have long been reducing the environmental impact of dairy farming by managing their land, air, and water resources, but continued efforts will only further improve the dairy industry’s role in sustainable agriculture. Much of the previous work focused on reducing methane emissions from dairy cows has focused on nutritional strategies, but other factors, such as animal genetics are likely to play a role. Currently, there is minimal work studying the impact of genetics on methane emissions.
Recently, we have received a grant from the Minnesota Rapid Agricultural Response Fund, created by the Minnesota Legislature to evaluate methane emissions in cattle at the University of Minnesota. Our objectives are to understand the effect of dairy breeding strategies on enteric emissions in dairy production systems. Baseline emissions will be collected on the WCROC dairy in Morris, and the St. Paul campus dairy, with the GreenFeed methane measuring System from C-Lock Inc based in Rapid City, South Dakota.
This project will evaluate Holstein and crossbred dairy cattle on the WCROC Dairy, St. Paul Campus Dairy and on commercial Minnesota dairy farms for methane emissions from various production systems. The project will analyze novel nutritional strategies to reduce enteric methane emissions of conventional and grazing dairy cattle. Furthermore, the project will understand nutritional and non-nutritional factors that increase efficiency of energy utilization of dairy cows. We will also evaluate feeding strategies and practices in the field that will help to reduce the release of, and help sequester, greenhouse gases.
The WCROC dairy in Morris milks between 200 and 275 cows twice daily and is representative of a mid-size Minnesota dairy farm. The St. Paul campus dairy milks 90 cows twice daily with 2 Holstein cow genotypes. These University of Minnesota research dairies provide an ideal testing opportunity to evaluate and demonstrate the effect of reducing greenhouse gas emissions. We have acquired 2 portable GreenFeed Systems that will be able to evaluate methane emissions for dairy cattle. The C-Lock GreenFeed system will provide research and extension personnel at the University of Minnesota to conduct research in challenging areas of nutrition and dairy cattle genetics. The system will monitor an animal's breath components to estimate the gases emitted by animals on a daily basis. The system is a portable, self-contained system designed to measure emissions from calves, heifers, or cows.
We began utilizing the GreenFeed system during mid-July at the dairy in Morris. So far, the results are variable depending on the nutrition, genetics, and time of day cows eat or visit the GreenFeed. Overall, our cows average around 350 grams of methane emitted per day.
This study is the first step to lower emissions on Minnesota farms and to develop resilient dairy farms. Results will be used to understand how genetic selection has improved sustainability of dairy cows and help improve our estimates of the energy requirements of dairy cows.