When reviewing this category, you should check:

• If CH₄ emissions from enteric fermentation have been identified as a key category, whether emissions from the significant sub-categories have been estimated using the Tier 2 method based on an enhanced livestock characterization;
• For a Tier 2 method:
• Whether disaggregated emission factors for sub-categories of animal species (e.g., by age and sex sub-groups, climate region, management practice, type of feed, etc.) have been used;
• Whether estimates of Gross Energy Intake (GE) are provided, in accordance with the characteristics of the livestock population, and models, animal characteristics and parameters are well documented;
• Whether a country-specific methane conversion factor (MCF) values have been used;
• Whether the basis of these data are reasonable, considering the livestock characteristics and country management practices, and how they compare with IPCC default values;
• For a Tier 1 method:
  • Whether the Party has demonstrated that any default factors used are applicable to the national circumstances of their livestock populations (e.g region and milk yield).

Reference:
IPCC Good Practice Guidance, Section 4.2