With the urbanization, the dairy farming system is undergoing industrialization to meet the growing demand for dairy products. Industrial farms have been reported to increase milk production per unit area because of the high breeding density and improve feed use efficiency of dairy cow, which may reduce the environmental impact intensities, such as non-CO2 emission in producing one unit of milk. However, industrialization also increases the energy input due to the use of mechanized equipment and thus increases CO2 emission. Anaerobic digestion of cow manure to produce biogas and using the digestate to produce bioenergy crops are cleaner ways for fossil energy saving. In this study, by combining field survey, model simulation and scenario analysis, we calculated the mitigation potentials of fossil energy consumption and CO2 emission in milk production using bioenergy production technologies in an average-sized industrial dairy farm, compared with milk production without bioenergy production technologies. Then, we estimated the manure excretion and CO2 equivalent emissions released from manure management from Chinaâ€™s dairy farming systems in 2017, and calculated the mitigation potential of CO2 emission if all dairy cow manure were treated by biogas fermentation plus waste nitrogen for bioenergy crops production. The cost-benefit of manure management with bioenergy production technologies was also analyzed to explore the economic potential of the manure management with bioenergy production technologies.
Keywords dairy production, energy consumption, bioenergy production, CO2 emission