A new study explores how sheep traits and feeding patterns influence methane emissions, providing insights that can support better breeding decisions and climate-mitigation strategies.
Understanding methane in sheep
Understanding key animal performance and nuisance factors associated with methane (CH4) output and feed intake is crucial in developing greenhouse gas mitigation strategies and incorporating these traits into international sheep breeding goals.
Study goals and design
The study, published in the journal New Ruminant Research, had 2 main goals:
- Find out what animal traits and environmental factors affect methane production and feed intake.
- See how methane output relates to feed efficiency and whether this varies by country.
Data collection across countries
Researchers measured methane in sheep from 6 countries (Ireland, Norway, New Zealand, Uruguay, France, and the UK) using different tools. They also tracked how much food each sheep ate, using various methods, while the sheep were indoors or outdoors and eating different types of feed.
Key patterns and differences
Because the studies involved different breeds, ages, and feeding systems, the factors influencing methane and feed intake varied by country. However, some patterns were similar everywhere:
- Bigger sheep generally produce more methane.
- The link between methane and how much food sheep ate ranged from weak to strong, depending on the country.
- Methane had only a weak connection to feed efficiency.
Carbon dioxide output trends
Carbon dioxide (CO₂) output also showed similar trends: it was strongly linked to weight gain and moderately linked to food intake, but only weakly linked to feed efficiency.
Implications for Research
Even though the data came from different places and methods, combining it helps scientists compare results and improve future research. The findings suggest that some relationships (like methane and body weight) are driven by biology, while others (like CO₂ and food intake) may depend on how measurements are taken. This matters because researchers want to find easy ways to estimate methane production, which is important for global climate accounting.
