Seasonal dynamics of feed carbon footprint in sheep field flocks under semi-intensive system in Karnataka, Southern India

Abstract

Feed management plays a crucial role in mitigating greenhouse gas (GHG) emissions from livestock production systems. Despite India possessing one of the largest sheep populations globally, information on the environmental impacts of sheep production remains limited. The present study was conducted in Karnataka, South India, where over 400 sheep from 18 semi-intensive flocks were monitored over a two-year period. A cradle-to-farm-gate life cycle assessment (LCA) approach was employed in accordance with ISO 14040/44 standards, using IPCC Tier 2 methodologies to quantify GHG emissions. Feed carbon footprint (CF) varied significantly across seasons, with the highest CF during winter (0.89 kg CO₂-eq day⁻¹ sheep⁻¹) and declining during the monsoon and post-monsoon (0.30–0.38 kg CO₂-eq day⁻¹ sheep⁻¹). Common grazing lands contributed 15 to 56% of total nutrient intake, depending on season, substantially reducing reliance on purchased feeds. Strategic incorporation of seasonal green fodder and crop byproducts lowered feed-related emissions by up to 55 to 65% and reduced per day per sheep feed costs up to 12.2%. The findings highlight the critical role of seasonal forage availability in reducing both emissions and production costs, particularly in dryland regions.