Emission factors estimated from enteric methane of dairy cattle in Andean zone using the IPCC Tier-2 methodology

Abstract

Enteric CH4 emissions from ruminant livestock represent a loss of dietary energy and contribute to greenhouse gas emissions, actually, that is depending on feeding level and diet composition. We calculated emission factors of methane depending to enteric fermentation of Holstein cattle in Andean zone of Colombia, based on methodology IPCC Tier 2. This study involved animal performance, management practices for improved livestock productivity, higher digestibility of pasture and forage from silvopastoral system of the association Pennisetum clandestinum/Trifolium repens on paddocks bounded by live fences of Acacia decurrens. For that, some model parameters and Tier-2 model equations were applied: body weight, mature weight, daily gain, weight loss, milk production, milk fat content, pregnancy rates and quality of feed to calculate gross energy GE. All these variations were used to investigate the effects on predicted CH4, emission in terms of the changes in the CH4 emission factor (MEF) in kg of CH4 per head dairy cattle−1 year−1. CH4 conversion factor (MCF) as a percentage of gross energy intake with feed, resulting in emission factor of 52 kg CH4 head−1 year−1 in SPS, 28 and 45% lower than in improved pasture of Lolium multiflorum and degraded pasture of Pennisetum clandestinum in rotation with potatoes, resulting in emission factors of 72 and 93 kg CH4 head−1 year−1 respectively. These emission factors were compared with the emission factors of Tier-1 and Tier-2 methodology used value Ym default of IPCC from national inventories. Through this research these emission factors can be applied for regional and national inventories in Andean areas of Colombia with these features.