Ardavan Ghorbani; Lida Andalibi; Farid Enferadi; Farzad Aghche Gheshlagh; Jamal Seyf Davati; Jaber Sharifi Niaragh
Volume 27, Issue 4 , December 2020, , Pages 722-731
Abstract
Forage quality information could help managers of rangelands to select appropriate grazing method to achieve higher animal performance without damage to ecosystem. The aim of this study was to investigate the nutritional value of Thymus kotschyanus, Artemisia melanolepis and A. austriaca in different ...
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Forage quality information could help managers of rangelands to select appropriate grazing method to achieve higher animal performance without damage to ecosystem. The aim of this study was to investigate the nutritional value of Thymus kotschyanus, Artemisia melanolepis and A. austriaca in different altitudes and phenological stages in 2016. According to the presense of the selected species, three rangeland sites in the southeast of Sabalan near Alvares ski resort including 2200-2400, 2600-2800, and 3000-3200 meters above sea level were selected. At each site 50 samples from each species were taken at three phenological stages. The nutritional value of the species was determined by measuring the percentage of dry matter, ash, organic matter, protein, fat, Acid Detergent Fiber (ADF), Neutral Detergent Fiber (NDF), macro elements (nitrogen, phosphorus, potassium, calcium, and sodium) and micro elements (iron, zinc, copper and manganese) and the results were analyzed in a completely randomized design using ANOVA. Duncan's multiple range test was used to compare the means. Considernig the difference in altitude in the habitat of T. kotschyanus and A. melanolepis, the effect of altitude factor on the studied traits in these two species was solely evaluated by independent t-test and the results showed that, altitude changes had no effect on the nutritional value and macro and micro elements of T. kotschyanus and A. melanolepis. The difference between phenological stages in species was significant. The highest and lowest percentage of organic matter were in seedling and growth stages for A. austriaca (94.43%) and A. melanolepis (91.49%), respectively. As phenological stages pass, there was a significant decrease in the percentage of fat, protein and ash in all three species (p < 0.05). The highest crude protein was observed in A. melanolepis at vegetative stage (17%) and the lowest in A. austriaca at seedling stage (7.5%). With the development of growth stages organic and dry matter, NDF and ADF were increased in the species. Phosphorus, potassium, nitrogen and sodium in the species were decreased significantly as phenological stages progress (p < 0.05). The highest phosphorus was recorded at vegetative stage in A. austriaca (0.34%) and the lowest (0.12%) in T. kotschyanus at the seedling stage. Overall, A. austriaca, A. melanolepis and T. kotschyanus have high nutritional value and suitable minerals, which can be used as substitute forage when other forage species are reduced in a given rangeland.