Interconnection Between Feed Resources Availability, Livestock Production and Soil Carbon Dynamics Under Smallholder System in Eastern Ethiopia

Abstract

Availability of feed resources, herd size and soil fertility status of grazing lands limit livestock production under smallholder condition in Ethiopia. Therefore, we studied the relationship between feed resources availability, livestock production and soil carbon (SC) balance under smallholder conditions in Mieso district of eastern Ethiopia. The JAVA model procedure was used to calculate the maximum number of animals in tropical livestock units (TLU) that can be maintained per unit area. The available feed resources were ranked based on their metabolizable energy contents. Feed balance was calculated based on DM availability and nutrient requirement of livestock in the study area. The SC balance was determined based on carbon inputs from manure, grazing and/or harvesting losses, residues of crop and roots, and soil organic matter decomposition. The JAVA model calculated the optimum level of feed use, livestock performances and soil carbon balance (dynamics), Moreover, monetary values of live weight gain (LWG) and/or loss, manure and draught power were calculated. The analysis of the JAVA model revealed that mean daily LWG and milk production (MP) per TLU increased linearly with decreasing herd size (HS), whereas, annual total LWG and total MP increased with increasing HS at 40% level of best use of feed use and HS of 722 TLU during the study. However, the SC balance at 40% of feed use was negative and decreased with increasing feed use. Moreover, the model estimated that maximum monetary value of LWG, manure and draught power were achieved at 60% feed use. Our study suggested that meat and/or milk production and SC balance could be increased by selective utilization of best feeds available at farmer level under the changing climate and global warming in the study area.