Grazing practices impact methane emissions

One of the biggest culprits of global climate change is methane – a potent greenhouse gas that traps heat in the atmosphere. Methane emissions from livestock production have long been scrutinized, and the environmental impact of these operations is often in question.

In a recent issue of Oklahoma State Extension’s Cow-Calf Corner newsletter, Paul Beck writes that the International Panel on Climate Change estimates nearly 23% of global greenhouse gas emissions come from agriculture, forestry, and other land uses. Roughly 44% of methane emissions come from these industries, and approximately 46% of total methane emissions can be attributed to ruminant animals.

Similar data on agriculture in the U.S. suggests the agricultural industry contributes about 9% of the country’s total greenhouse gas emissions, with only 3.2% of total emissions being from methane produced by ruminant animals. While these numbers may seem relatively small compared to international figures, Beck notes that greenhouse gases from cow-calf and stocker operations make up 70% to 80% of greenhouse gas emissions from the beef sector.

“This is because cattle consuming a high-forage diet have increased methane emissions, and brood cows live on pastures continuously and have a single offspring per year,” the extension beef cattle specialist explains.

Despite this, livestock are not necessarily to blame. Rather, methane emissions can be addressed with proper forage management. Beck says high-quality forage and rotational grazing can reduce methane production during rumination. Diet supplementation can also promote better nutrition and aid in fiber digestion, further preventing the presence of methane-producing ruminal bacteria.

Beck says the impact of these strategies can explain why greater amounts of greenhouse gases come from livestock in developing countries. These nations tend to feed animals low-quality forage and engage in poorer production practices, which result in low market weights and older ages at slaughter.

“Globally, 75% of greenhouse gasses from ruminant animals are produced in developing countries, producing two times the greenhouse gas per pound of carcass than in developed countries,” Beck states. “Emission rates per pound of product in developed countries are low due to improved grazing management, higher pasture quality and digestibility, and more intensive feeding practices.”

Although methane emissions from cattle will never be obsolete, prioritizing forage quality and supplementing animals’ diets can help minimize them. In conclusion, Beck encourages producers to refine their grazing approach and demonstrate diligent animal husbandry.

Amber Friedrichsen

Amber Friedrichsen served as the 2021 Hay & Forage Grower editorial intern. She currently attends Iowa State University where she is majoring in agriculture and life sciences education-communications and agronomy. Friedrichsen grew up on her family’s diversified crop and livestock farm near Clinton, Iowa.