When it comes to climate change, one of the most significant yet rarely discussed contributors comes from an unexpected source: cow burps. Now, scientists may have found a potential solution that could reshape the future of sustainable cattle farming: seaweed.
To understand the scale of this challenge, consider the numbers: Livestock account for 14.5% of global greenhouse gas emissions, with the largest portion coming from methane that cattle release when they burp. In the United States alone, there are over 64 million beef cattle and nine million dairy cows contributing to these emissions. When cattle digest fibrous plant materials, their specialized stomach compartments host microorganisms that break down tough cellulose, producing methane as a byproduct. Grazing cattle, which consume more fibrous grass than their feedlot or dairy counterparts, produce even more methane as a result.
“Beef cattle spend only about three months in feedlots and spend most of their lives grazing on pasture and producing methane,” explains senior author Ermias Kebreab, professor in the Department of Animal Science at the University of California, Davis, in a media release. “We need to make this seaweed additive or any feed additive more accessible to grazing cattle to make cattle farming more sustainable while meeting the global demand for meat.”
Breaking New Ground: Testing Seaweed Supplements in Grazing Cattle
Previous research has shown promising results with seaweed supplements, reducing methane emissions by 82% in feedlot cattle and over 50% in dairy cows. However, finding effective solutions for grazing cattle has proven particularly challenging because they spend most of their time on open pastures, making daily supplementation difficult. The UC Davis study represents the first worldwide test of seaweed supplements on grazing beef cattle.
To tackle this challenge, researchers developed a precisely formulated supplement called Brominata, using a specific seaweed species, Asparagopsis taxiformis. The pelleted supplement contained 20% of the seaweed along with distillery solubles (15%), wheat middlings (64.8%), and a small amount of palatability enhancer (0.25%). This careful formulation aimed to make the supplement both effective and palatable to cattle.
The study took place at Matador Ranch in Montana, where researchers worked with 24 Wagyu-Angus crossbred steers. The cattle were divided into two equal groups: one received standard feed pellets, while the other received the Brominata supplement. Using sophisticated monitoring equipment called the GreenFeed system, researchers tracked the animals’ emissions during feeding sessions that occurred up to three times daily over a 70-day period.
The results revealed three distinct phases: a three-week ramp-up period as cattle adjusted to the supplement, a three-week optimal phase where effects were most pronounced, and a two-week decreasing phase. During the optimal and decreasing phases, cattle receiving the seaweed supplement showed an average reduction in methane emissions of 37.7% compared to the control group. Importantly, this significant decrease occurred without negatively impacting the animals’ growth or feed intake.
The researchers discovered a precise relationship between the amount of bromoform (the active compound in the seaweed) consumed and methane reduction: for every 100 milligrams of daily bromoform consumption, methane emissions dropped by approximately 20%. With an average bromoform intake of 193 milligrams per day, the study demonstrated that even voluntary consumption of the supplement could achieve significant results.
The study, published in the Proceedings of the National Academy of Sciences, also tracked other greenhouse gases. Carbon dioxide emissions showed a modest 4% reduction in supplemented cattle, while hydrogen emissions increased significantly – rising 85.7% in production and 76.5% in yield. This increase in hydrogen emissions was expected, as it indicates the successful disruption of methane-producing digestive processes.
Looking toward practical implementation, Kebreab notes, “Ranchers could even introduce the seaweed through a lick block for their cattle.”
This approach could solve one of the biggest challenges in grazing operations: delivering supplements to cattle that often range far from ranch headquarters. While ranchers typically supplement their cattle’s diet during winter months or when grass becomes scarce, having a delivery method that works year-round could maximize the climate benefits.
The Climate Impact of Cattle: A Growing Global Challenge
The global implications of this research extend far beyond American ranches. Pastoral farming supports millions of people worldwide, often in regions most vulnerable to climate change. Making cattle grazing more environmentally sustainable could help protect both these traditional farming practices and the communities that depend on them. This aligns with findings from a related PNAS article emphasizing the importance of improving livestock production in low and middle-income countries through better genetics, feeding practices, and animal health measures.
For the millions of ranchers worldwide who manage grazing cattle, this research offers a practical path toward climate change mitigation. While the 37.7% reduction might not match the more dramatic results seen in controlled feeding situations, it represents a significant breakthrough for grazing operations. The simplicity of the solution – a supplement that can be delivered through existing feeding practices – makes it particularly promising for widespread adoption as the world seeks to balance increasing demand for meat with environmental protection.
Source : https://studyfinds.org/cow-burps-seaweed-save-climate/
