Assessment of Renewable and Non Renewable Energy Use in Dairy Farms with Different Herd Sizes in Iran

The aim of this study was to compare energy consumption in dairy farms with different sizes. Sources of energy include non renewable sources such as fossil fuel, and electricity and renewable sources such as forage, concentrate, machinery, labor, and water. The required data were collected from 42 dairy farms in Tehran province, Iran and were analyzed to assess energy consumption based on different herd sizes. In this study, the average consumption of non-renewable energy in small, medium, and large dairy farms per kg fat and protein corrected milk were respectively 5.95 MJ kg-1, 3.39 MJ kg-1 and 1.71 MJ kg-1 (P<0.0002). The largest share of energy consumption in all dairy farms was related to feed; 81.49%, 84.37% and 88.62% for small, medium, and large dairy farms, respectively (P<0.0002). Also, energy ratio for small, medium, and large dairy farms were calculated as 0.11, 0.16 and 0.23, respectively (P<0.0001). Likewise, energy productivity in small, medium, and large dairy farms was 0.033 kg MJ-1, 0.047 kg MJ-1 and 0.068 kg MJ-1, respectively (P<0.0001). The less non-renewable energy use per kg fat and protein corrected milk in large dairy farms would lead to reduce pollution and protect the environment which in turn cause to a sustainable and more efficient production system.