Document Type : Research Paper
1 Rangeland Research Division, Research Institute of Forests and Rangelands, AREEO, Tehran
2 PhD of Range Management, Isfahan Agriculture and Natural Resources Research and Education Center, AREEO, Isfahan
3 Rangeland Research Division, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization
4 Associate Professor, Rangeland Research Division, Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO), Tehran
For the experiment, at the beginning of each growing season, an adult Naiini sheep (3-4 years old) was used as representative of the herd and used in annual censuses. Grazing time measurement continued at the beginning of the growing season and during the four growth stages. Census time at each growth stage was performed one hour after daily grazing, and in three continuous 20-min periods (repeat experiment). Considering the time of concentration of the animal and the tendency of the animal to different species, the palatability class of each plant species was determined. The results showed that during all the years under study, grazing concentration of Naiini sheep on annual species (Grass and Forbes), litter, Stachys inflata, Artemisia sieberi, Stipa arabica, Noaea mucronata and Hertia angustifolia was observed. Based on the results, annual and litter species were classified as Class І species, Stachys inflata as Class II plant and Artemisia sieberi, Stipa arabica, Noaea mucronata and Hertia angustifolia as Class Ш species.
The results showed that the palatability of the species was not the same as the change in plant composition during the growing season. Therefore, it is incorrect to consider the same palatability class for each species at different stages of development, and it is necessary to pay more attention to the description of pasture design services when calculating grazing capacity.