Screening of Grasses’ Chemical Composition Variability and Methane Emissions in Colombian Livestock Ecoregions Using Digital Bromatology

Grasses’ nutritional characteristics and management are fundamental for grazing cattle to guarantee sustainability in tropical conditions. This study aims to analyze the pastures’ chemical composition variability and methane emissions in different Colombian ecoregions and productive activities using digital bromatology data. Records of grasses’ chemical composition estimated through drone imagery were evaluated in seven Colombian ecoregions, according to three productive activities (dairy–dual purpose, breeding, and fattening). Dry matter intake (DMI) and enteric methane emissions were estimated using mathematical models. Data analysis included multivariate and univariate methods. Livestock farms located in ecoregions such as Antioquia and Eje Cafetero, Medium Magdalena, and Southeast, dedicated to dairy–dual‐purpose productive activities, presented pastures with better chemical composition (higher protein, energy, minerals, and low fiber) than farms dedicated to livestock breeding or fattening distributed in different low‐medium tropic ecoregions. The estimated absolute enteric methane emissions were higher in dairy–dual purpose animals consuming better quality pastures than in breeding and fattening animals in low‐quality pastures (on average 250 vs. 207 g/day, respectively), although emissions were comparable when expressed in terms of methane yield (25 vs. 22 g/kg DMI, respectively). All ecoregions must improve the chemical composition and management of pastures used for grazing to attain sustainable livestock systems. These results demonstrate the usefulness of digital bromatology to characterize the forages’ chemical composition at a regional scale.