Investigation of Forage Quality of Vetiveria zizanioides in Semi-Steppe Region of Maravehtappeh, Golestan Province, Iran

Information on forage quality in phenological stage could help range managers to choose suitable grazing method to achieve higher animal performance without detriment to vegetation. Vetiver grass (Vetiveria zizanioides) is a non-native perennial grass that was introduced to the Iran in 2008. This plant is a multi use species that could be considered from different viewpoints. Thus, its forage quality in three phenological stages (vegetative, flowering and maturity) was investigated. Samples of each stage were collected and analyzed for 7 quality traits such as Crude Protein (CP), Acid Detergent Fiber (ADF), Dry Matter Digestibility (DMD), Metabolizable Energy (ME), Digestible Energy (DE), Ash content (Ash) and Total Digestible Nutrient (TDN). Data were statically analyzed using One-way analysis of variance (ANOVA) and mean comparisons were done by Duncan method. The results indicate that there was a significant difference among phenological stages for all the traits (p<0.01). As the plant age increased, the quality values including CP (from 8.89% to 5.25%), DMD (34.79% to 31.63%), ME (3.91 to 3.38 MJ/Kg), Ash (6.7% to 5.5 %,), DE (1.71 to 1.64 Mcals/Kg) and TDN (23.07% to 20.79%) were decreased while ADF was increased (from 63.72% to 65.7%). This led to the reduction of Vetiver grass forage quality. Because of lower values of CP, ME and DMD (except vegetative stage) and higher values of ADF, it was suggested that this species had no prominent place in the ruminant's diet. However, it played important roles in soil conservation and it may be complementary to the native vegetation because it is available at different times of the year considering its phenology and growth season.