Forage Nutritive Values of Cymbopogon olivieri before and after Essential Oil Extraction in Khuzestan Province’s Rangelands, Iran

This study was performed to evaluate the forage nutritive value of Cymbopogon olivieri before and after conducting the essential oil extraction in rangelands of Khuzestan province, Iran. In this study, the aerial parts of Cymbopogon olivieri were collected in flowering stage from 10 natural regions located in Khuzestan province in 2016. Regions included ChalGandali, TalkhabKalat, Bardmar, Morad Abad, Tembi, Dezful, Andika, Lali, Shoushtar, and Izeh. Essential oil composition was analyzed by GC/MS. The forage quality traits including Crude Protein (CP), Dry Matter Digestibility (DMD), Water Soluble Carbohydrates (WSC), Crude Fiber (CF), Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF), and total Ash were measured. After normalizing the gathered data, the means of the traits were compared by Duncan’s multiple range test (p <0.05) in SAS software. The 21 components were identified in the essential oil of the plant species. The result showed that the highest mean values of CP, DMD, WSC, CF, ADF, NDF, and total Ash were obtained as 4.83%, 48.03%, 14.9%, 76.63%, 50.12%, 84.59%, and 3.98%, respectively. The result showed that phenological stage had significant effects on forage quality. The higher amount of NDF (77.01), ADF (40.54), and CF (63.64) were observed after essential oil extraction stage, but the higher amount of CP (3.31), WSC (11.99), and DMD (46.03) were observed before essential oil extraction. In this study the range of changes for CP ranged from 1.26 to 5.06, DMD between 45.89 to 49.27, WSC between 7.27 to 11.53, ADF 40.40 to 45.5, total Ash ranged between 3.14 to 4.94, CF ranged from 58.6 to 65.82 and NDF was in the range of 63.49 to 70.72. So, it was concluded that since the essential oil extraction led to decreasing of forage quality have more benefit for dairy and meat production.