Optimizing Energy Use in Pig Production: An Examination of Iowa Systems

摘要

Energy is used in all aspects of pig production, from the manufacture of materials used in building construction to the cultivation and processing of feedstuffs. Historically the availability of fossil fuels has minimized pressure to consider all uses of energy in pig production. Rising energy prices, uncertain access to petroleum supplies, and recognition of the environmental impacts of fossil fuels are increasing awareness and incentive to reduce consumption of limited resources. This project estimates non-solar energy use for pig production options in Iowa.The baseline system produces 15,600 pigs annually using confinement facilities and a corn-soybean cropping sequence. Diet formulations for the baseline system include supplemented synthetic amino acid L-lysine and exogenous phytase. The baseline system represents the majority of current pork production systems in Iowa and the Upper Midwest where most U.S. swine are produced. This system is designed to minimize land-surface area requirements and encourage maximal pork production per unit of feed net energy and standardized ileal digestible lysine fed to pigs. The baseline system for swine production in Iowa is estimated to require 5.5 MJ non-solar energy/kg of live weight pig produced. In general producing pigs in Iowa in 2009 requires about 85% less non-renewable energy compared to 1975.An alternative system using hoop barns for grow-finish pigs and gestating sows was also evaluated. Using bedded hoop barns for gestating sows and grow finish pigs requires less energy to heat and ventilate buildings, but more energy to grow and process feed than conventional systems. Using hoop barns for swine production requires more feed and thus more non-solar energy to grow and process feed ingredients. However the savings in non-solar energy associated with operating hoop barn-based swine systems relative to conventional confinement systems nearly offsets those inputs. The alternative hoop-based system would require 5.6 MJ non-solar energy/kg live weight.The total energy used for both housing systems is very similar. Energy use for pig production is influenced by crop sequence and diet strategy with nitrogen management being a critical leverage point.