Dietary characteristics and body weight input improve the prediction of enteric methane production from growing-finishing pigs

The objective of the present study was to identify dietary and animal factors that affect enteric methane (CH₄) production in growing-finishing pigs. Moreover, the study aims to develop and compare the predictive accuracy of the developed models with the existing equations using the Tier 1 approach and equations considering nutrient availability. A dataset from 13 studies containing 290 individual animal observations on 107 growing-finishing pigs was used to develop the prediction model for enteric CH₄ production. The predictive ability of the newly developed models was evaluated and compared with the extant equation proposed by the Intergovernmental Panel on Climate Change (IPCC) Tier 1 approach and extant prediction equations that consider substrate available for fermentation. Production of enteric CH₄ was predicted by fitting mixed-effects models with random effects of animal and study. The newly developed models for enteric CH₄ production, which include dietary characteristics and animal body weight, surpass the current IPCC Tier 1 model used in national inventories, demonstrating better precision and accuracy. Therefore, the equations developed in this study can be used in the pork industry to estimate the effect of feeding strategies to mitigate enteric CH₄ production from growing-finishing pigs and to improve the national inventories of CH₄ production.