University of California Agriculture and Natural Resources (UC ANR) researchers announced on March 20 that they are conducting a new study at the Sierra Foothill Research and Extension Center to evaluate the use of red seaweed as a supplement for reducing methane emissions in grazing cattle.
The research is significant because methane from ruminants such as cows, sheep, and goats accounts for about 6% of human-related greenhouse gas emissions. Reducing these emissions is considered an effective short-term strategy for climate change mitigation. The project aims to find practical ways to deliver seaweed-based additives to cattle that graze freely over large areas, where traditional feeding methods used in feedlots or dairies are not feasible.
Andrea Warner, livestock and natural resources advisor for UC Cooperative Extension in Sutter, Yuba, Placer, and Nevada counties, said, “The challenge now is finding a method to bring the seaweed product to cattle that graze on pastures.” Warner explained that while controlled environments allow for consistent feeding with mixed rations, open pastures present difficulties due to the animals’ freedom of movement. Previous studies showed inconsistent results when red seaweed was added to mineral supplements placed in open feeders on pastures. Sheila Barry, livestock and natural resources advisor for UC Cooperative Extension in the San Francisco Bay Area and lead author of last year’s study funded by the Russell L. Rustici Rangeland and Cattle Research Endowment at UC Davis, said: “Our results really indicated that we need better measurement capabilities.”
To address these challenges, the current project uses two new technologies: a “Smart Feeder” system that tracks individual animal consumption using radio-frequency identification (RFID), and a “Green Feeder” device that measures methane emissions while dispensing alfalfa pellets as incentives. Warner said, “The Smart Feeder records exactly how much mineral each animal consumes individually, which also helps us calculate how much red seaweed it ingests.” Barry added about the Green Feeders: “The Green Feeders measure methane, but for that to happen, animals have to use these feeders between three and five minutes.”
Researchers faced additional obstacles such as unreliable solar power during cloudy weather and logistical delays caused by calving season. Despite these setbacks, Warner said: “Cows, rough terrain, weather events, research and technology are difficult factors to coordinate but we are making progress.” Nikolai Schweitzer, director of agricultural operations at Sierra Foothill REC noted: “We have machinery, intellectual talent, passion and employees with great perseverance so we can have a fully serviced research center here in Browns Valley.”
UC ANR secures funding through public contributions according to its official website. The organization promotes sustainable practices aimed at strengthening resilient ecosystems and economic vitality according to its official website. It operates nine research centers representing California’s diverse ecosystems according to its official website and has gained recognition for linking research with community needs according to its official website. As part of the University of California system managing Cooperative Extension services according to its official website, UC ANR conducts more than 33,800 educational events annually with over 18,400 volunteers according to its official website. Through educational programs across all 58 counties—delivered via workshops and partnerships—the organization mobilizes volunteers and research centers statewide according to its official website.
The current study is expected to conclude by late 2027.
