Introduction: Environmental crises and resource depletion have adversely affected environmental resources and food security in the world. Therefore, given the forecast for global population growth in the coming years and the need to produce more food, attention to the issue of environment, energy consumption and sustainable production is of great importance. The purpose of this study was to evaluate the pattern of energy consumption, environmental impacts and optimization of the studied Energy indicators in dairy cattle breeding industrial units in Khuzestan province.
Materials and Methods: This research was conducted in Khuzestan province located in the southwest of Iran. Energy indicators including energy ratio, energy efficiency, specific energy and net energy were used to determine and analyze the relationships between output and input energy. In addition, the life cycle assessment methodology also was used to assess the environmental impact. Life cycle assessment includes goal statement, identification of inputs and outputs, and a system for assessing and interpreting environmental impacts, and can be a good yardstick for assessing environmental issues related to product production. The life cycle assessment method used in this study was CML-IA baseline V3.05, which includes four steps of selecting and classifying impact categories, characterizing effects, normalizing, and weighting. Data envelopment analysis method with Anderson-Peterson model was used for optimization. This method identifies the most efficient production unit and makes it possible to rank all farms in the region. In this study, each production unit (each farm) was considered as a decision unit (DMU) and the efficiency of production units was determined based on CCR and BCC models for each farm.
Results and discussion: The results showed that the input and output energies per cow per day were 173.34 and 166 mj, respectively. Livestock feed and electricity with 65.47% and 65.47%, respectively, and the oil used for tiller-scraper lubrication of fertilizer collection with 0.01% had the lowest input energy. Energy efficiency, energy efficiency, specific energy and net energy were calculated as 0.95, 0.13 kg/mJ, 7.51 mJ/kg and -7.20 MJ per cow, respectively. The results showed that in all groups of the effect, except for the non-living discharge potential related to fossil fuels, animal feed had the highest environmental emissions. In the impact group of abiotic discharge potential, animal feed, machinery and livestock equipment had the highest environmental impact. In the group of non-living discharge potentials related to fossil fuels, electricity had the highest effect. The number of efficient units was determined using CRS model, 7 units and the average production units in terms of efficiency was 0.78. In the BCC model, there were calculated with 20 production units with high efficiency and the average efficiency of the scale was computed equal to 0.78. In most of the effect groups, animal feed and in the effect group, non-living discharge potential, animal feed, machinery and livestock equipment had the highest environmental effects. According to the results, animal feed had the highest environmental emissions in all impact groups except non-living discharge potential related to fossil fuels.
Conclusion: In dairy farms in Khuzestan province, animal feed and electricity had the highest energy consumption. In most of the effect groups, animal feed and in the effect group, inanimate discharge potential, animal feed, livestock machinery and equipment had the highest environmental effects. Due to the length of the heat period and the intensity of the solar flux, the use of solar panels on the roof of the farm to supply the required electricity can reduce the consumption of non-renewable energy and reduce the intensity of radiation under the roof of the Livestock.