Zahra Mohebi - Department of Natural Resources, Faculty of Agricultural Sciences & Natural Resources, Razi University, Kermanshah, Iran
Fatemeh Sefidkon - Research Institute of Forests and Rangeland, Agricultural Research, Education and Extension Organization (AREEO) Tehran, Iran
Gholam Ali Heshmati - Department of Range Management, Faculty of Range and Watershed Management, Gorgan University of Agricultural Sciences & Natural Resources, Gorgan, Golestan Province, Iran

The purpose of the present research was to evaluate the essential oil and forage quality optimizer (EFO) apparatus to improve oils, while preserving forage quality and digestibility for the first time. Prangos ferulacea  L. Lindl aerial parts were collected and used for the essential oil, forage quality, and digestibility analysis. Effects of temperature treatments (۶۰, ۷۵ and ۹۰ ° C) at EFO method on essential oil were compared to steam distillation. After the oil extraction, the nutrient compositions were measured and compared with the samples of before extracting. The results showed a significant increase in the content of essential oil in ۷۵ °C compared to the other treatments (p<۰.۰۵). Also, the quality and the digestibility of fodder were as follows: SD method < before the essential oil extraction < the EFO innovative method (۷۵ °C). Therefore, temperature of ۷۵ °C in EFO was concluded as the optimum temperature, for increasing both of the quality and quantity of oil as well as preserving the quality and digestibility of forage. It is suggested that the EFO can be tested to obtain a more qualitative essential oil and forage that can be exploited in the pharmaceutical and animal food industry.

Essential oil and Forage quality Optimizer (EFO), SD (Steam distillation), Prangos ferulacea, Forage quality, Digestibility