QUANTIFYING ENTERIC METHANE EMISSIONS FROM SMALL RUMINANTS IN A MEDITERRANEAN ENVIRONMENT

Abstract

Greenhouse gas (GHG) emissions have become a critical factor in climate change. The rise in temperature observed over the last century underscores this impact. Livestock alone contributes significantly to these emissions, accounting for about 14.5% of all human-induced GHGs. Among these, methane (CH4) constitutes a substantial portion, originating primarily from enteric fermentation. This process contributes to approximately 30% of global enteric CH4 emissions, with small ruminants being responsible for about 6.7% of total livestock emissions. For accurate GHG inventories, reliable estimation of CH4 emissions is paramount. This often relies on factors such as the methane conversion rate (Ym), a key variable used in determining the proportion of an animal's energy intake converted to CH4. Although continuously refined, obtaining precise values for Ym involves direct measurements of CH4 emissions along with intake and digestibility of specific diets. This paper provides a comprehensive overview of the significance of Ym in GHG inventories and highlights the necessity of accurate measurements in emission reduction strategies.