New studies show dairy’s environmental footprint shrinking
Two recent studies have discovered a reduction in dairy’s climate contribution. One study in the Journal of Dairy Science examined milk production’s environmental footprint for over 50 years. The other study in the Journal of Animal Science updated previous findings on the dairy cattle industry’s environmental impact for the 10 years between 2007 and 2017.
The first study, completed by a group of researchers at the University of California- Davis (UC-Davis), conducted a life-cycle environmental assessment of the California dairy farm production and found that the climate footprint of milk production has significantly decreased over the last 50 years, with the amount of greenhouse gas emissions produced per unit of milk decreasing by more than 45% due to increased milk production efficiency. The researchers also found the amount of water used per unit of milk decreased 88%, and drastic improvements in feed crop production and agricultural byproduct utilization, which led to the reduction in the number of natural resources used in production, including land, water, fossil fuels, and energy. "Cows are natural bioprocessors and upcyclers of nutrients," said Dr. Kevin Comerford, Chief Science Officer for California Dairy Research Foundation (CDRF) in a press release. "As a result, cows will continue to play essential roles in healthy and sustainable food systems all over the world.”
"The study documents the productivity, efficiency, and overall sustainability of milk production in California and the critical role dairy cows play in regenerative agricultural practices and sustainable food systems," Dr. Ermias Kebreab, UC-Davis professor and Sesnon endowed chair who assisted graduate students in this project, told Feedstuff. CDRF supported the study, and Chairman Richard Wagner stated, "While there is always more work to be done, the findings show a significant overall improvement in environmental performance, producing more wholesome, nutritious milk and dairy products with fewer natural resources, less water, less energy, and fewer fossil fuels."
In the second study by Jude Capper, with the Livestock Sustainability Consultancy in the U.K., and Roger Cady, with Cady Agricultural Sustainability Specialties in Lake St. Louis, Mo., the researchers updated their previous findings comparing the environmental impact of U.S. dairy production in 1944 with 2007. Capper and Cady also reported that milk production has increased over time. Additionally, the pair stated that the resources required to produce 1 mmt of energy-corrected milk in 2017 were reduced significantly compared to those required in 2007. In 2017, the industry used "74.8% of the cattle, 82.7% of the feedstuffs, 79.2% of the land and 69.5% of the water as compared to 2007. Waste outputs were similarly reduced, with the 2017 U.S. dairy industry producing 79.4%, 82.5% and 85.7% of the manure, nitrogen and phosphorus excretion, respectively."
In their publication, the researchers conclude that “The U.S. dairy cattle industry has made considerable strides over past decades in acknowledging and responding to consumer concerns regarding the environmental impacts of dairy production.” Capper and Cady also recommended that “The focus must be on improving all three facets of sustainability (environmental responsibility, economic viability, and social acceptability) in a holistic manner—a challenge that the U.S. dairy industry should be able to meet most successfully.”