Study reveals features of cattle with high methane emissions

In a new study from Tohoku University, scientists have gained a better understanding of physiological responses in cattle with high methane emissions. In particular, the researchers investigated the metabolic characteristics of Japanese Black cattle.

In 2022, Japan’s agricultural sector produced 32.3 million tons of greenhouse gas emissions, and nearly 25 percent of these emissions are linked to enteric fermentation within livestock. 

Grazing animals such as cattle, sheep and goats are known as ruminants. These animals release enteric methane as the plant materials they feed on decompose and ferment inside of their bodies. 

To reduce the emissions associated with grazing livestock, experts have been trying out new additives and feeding management systems. 

“Enteric methane emitted by domestic animals is of primary concern in the livestock industry,” wrote the authors of the current study. “Ruminants generally have higher methane emissions than monogastric animals because of a long digestive tract and an extensive ecosystem in the rumen that is inhabited by numerous microorganisms, including methanogens.”

A team led by Professor Sanggun Roh from Tohoku University’s Graduate School of Agricultural Science used physiological parameters such as blood metabolites, hormones, amino acids, rumen fermentation, and liver transcriptomes to analyze the metabolic and nutritional features that may influence methane emissions. 

“We found cattle exhibiting high enteric methane to have a higher butyrate and lower propionate ratio,” said Professor Roh.

The experts also discovered that the concentration of amino acids decreased –  while levels of ketone bodies and insulin increased – in cattle with significant concentrations of methane. These changes occurred as cattle with high methane emissions actively utilized amino acids to replenish the energy lost during methane production.

“Our results suggest that physiological differences and liver transcriptomes could be applied to monitor the levels of methane emissions from Japanese Black steers,” said Professor Roh. “We are hopeful the relationship in this study leads to new perspectives.”

The study is published in the journal Scientific Reports.

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By Chrissy Sexton, Earth.com Staff Writer