Dairy production faces scrutiny for methane (CH4 ) emissions, a potent greenhouse gas primarily produced during ruminant digestion. From a farmer’s perspective, these emissions also signify a loss of valuable carbon initially paid for in feed, underscoring inefficiencies in converting feed energy into milk. Two metrics commonly used to evaluate CH₄ emissions in dairy cattle are methane yield (MEY), the methane produced per kilogram of dry matter intake (DMI), and methane intensity (MPM), methane emitted per kilogram of milk produced. These metrics offer insights into emissions efficiency and have significant implications for both environmental sustainability and milk production economics.
Methane yield (MEY)
MEY measures methane emissions per kilogram of feed consumed, providing insight into rumen fermentation efficiency. Lower MEY indicates better feed digestion, benefiting both the environment and farm economics. Factors influencing MEY include:
- Feed Quality and Composition: High-energy, low-fiber diets improve fermentation and reduce carbon losses as methane.
- Rumen Function: Efficient microbial activity optimizes energy conversion and minimizes methane emissions.
- Stage of Lactation: MEY often increases later in lactation as metabolic changes and lower feed intake alter fermentation dynamics.
Although improving MEY can optimize feed utilization and reduce costs, it often requires investing in higher-quality feeds, necessitating strategic ration balancing to ensure profitability.
Continue reading this article published in Feed & Additive magazine.
