Preference value of forage plants for cattle grazing in pasture of Lavash mountainous rangelands

Knowledge of livestock grazing behavior is one of factors of optimal and sustainable rangeland management. For optimal management of mountain rangelands, a study was conducted in the rangelands of Lavash. This is located in the Central Alborz Protected Area, and grazed by native hybrid cows. Measuring the vegetation characteristics of the rangelands those areas with 30 plots of 1 × 1 square meter, in three survey strips parallel transects with a distance of 50 meters from each other's, and a length of 100 meters in 2018 and 2019. According to the obtained results, the amount of forage consumption was almost twice of what was range capacity. The preference value of most of the studied species was estimated between 32 and 35% by weighing usage forage method. Palatability category and grazed time percent of each plant species was determined by using camera recording. Plant distribution on rangeland and plant cover percent effected on grazed time percent in the last month during grazing season. Hybrid cattle had unique desire to breed most of the species except for three species belong to Poaceae, Bromus tomentellus, Alopecurus textilis and Hordeum brevisubulantum which were considered more palatable. To calculate the weighted average percentage of preference value of each plant type, rangeland manager could be choose a range of decisions about each of the plant species indices include: range production, plant coverage percentage, and plant density, according to the type of vegetation type, the importance of the role of each plant species and other environmental conditions.