Additional data collection for Tier 2 greenhouse gas inventory in pig production in Vietnam
This study aims to strengthen the accuracy of Tier 2 greenhouse gas (GHG) inventories for Vietnam’s pig sector by addressing key data gaps in transitioning from the Tier 1 approach. Field surveys, focus group discussions (FGDs), and expert consultations were conducted to collect country-specific data on pig growth stages, sow productivity, breed structure, feeding practices, and manure management across four time periods (1994–2000, 2001–2010, 2011–2020, and 2021–present). Results indicate that field survey provide the most reliable and representative source for quantitative parameters such as feed intake and productivity, while FGDs are particularly effective for qualitative assessments of breed distribution, farming systems, and manure management. Expert judgment is valuable for historical estimates but is less precise for dynamic factors. The study recommends periodic data collection every 3–5 years for pig production stages, sow productivity, breed structure, and manure management; every 5 years for feed intake and composition; and immediate updates when farming systems change. Implementing these recommendations will significantly improve the accuracy and transparency of Vietnam’s livestock GHG inventory, thereby supporting more effective GHG reporting and the development of sustainable livestock policies.
