Determining the Preference Value of Perennial Grasses Using Preference Index and Sheep Grazing Time Methods in Grasslands of the Middle Alborz, Iran

Document Type : Research and Full Length Article


1 Ghazvin Research Center for Agriculture and Natural Resources, Department of Forest and Rangeland, Iran

2 Department of Natural Resources, Gorgan University of Agriculture and Natural Resources, Iran

3 Islamic Azad University Bushehr Branch


Preference value means livestock preference to eat some plants relative to other plants or species. Accordingly, by studying the preference values, the range managers could determine the rangelands grazing capacity to achieve the optimum performance of livestock and to guarantee the stability of rangeland ecosystem. The objective of this study was to determine the preference value of perennial grasses using two methods of preference index (species feeding frequency) and sheep grazing time (feeding time recording) in a semi-steppe rangeland in the middle Alborz Mountains of Iran during four consecutive years (2010-2013). The collected data were tested for normality and then, analyzed by the software of SAS9.1. The means comparisons were made using the Duncan method. Results showed that sheep preferred five grass species (Bromus tomentellus, Festuca ovina, Dactylis glomerata, Agropyron intermedium, and Agropyron trichophorum) in the rangeland. There were significant differences between species and years for grazing time method; however, there were no significant differences for preference index. Also, there were significant differences between months within years for both methods. Results showed that A. trichophorum with the average value of 13.8% grazing time was ranked as the first species followed by D. glomerata with the average value of 11.1% as the second one (Grazing time method). There were no significant differences between A. trichophorum, B. tomentellus, D. glomerata and F. ovina regarding the preference index with the average values of 0.57, 0.75, 0.70 and 0.56, respectively. Overall, the results indicated that grazing time percent method in semiarid rangelands gives more realistic results as compared to the preference index method because of the concrete and tangible results.


Main Subjects

Abdollahi, T.G.A., Dianati Tilaki, TGA., Farzadmehr, J., Sohrabi, H., 2009. Relative palatability of plant species for camel in southwest of Birjand desert area. Rangeland 3(3): 428-443. (In Persian).
Ahmadi, A., Sanadgol, A., Mohseni, S.M., Arzani, H., 2009. Investigation of grazing behavior and diet selection by Zandi sheep (Case study: desert rangelands of Houze Sultan, Qom). Rangeland 3(2):232-245. (In Persian).
Amiri, F., Mohamed Shariff, A., Tabatabaie, T., Pradhan, B., 2014. A geospatial model for the optimization grazing management in semi-arid rangeland of Iran. Arabian Journal of Geosciences 7(3): 1101-1114.
Amiri, F., Shariff, A.R.M., Tabatabaie, T. 2012. Monitoring Land Suitability for Mixed Livestock Grazing Using Geographic Information System (GIS). In: Alam BM (ed) Application of Geographic Information Systems. In Tech, Croatia.
Aregheore, E., Ali, I., Ofori, K., Rere, T., 2006. Studies on grazing behavior of goats in the Cook Islands: The Animal-Plant complex in forage preference/palatability phenomena. Inter. Jour. Agric  Biol., 8(2):147-152.
Ashouri Sanjabi, P., Fayaz, M., Zare, N., Gharanjik, A., Yeganeh, H., Afrougheh, S., 2013. The Study of Preference Values of Forage Species and Grazing Behavior of Tali Goat in Chabahar Rangelands of Iran. Jour Rangeland Science, 3(4): 312-320.
Azadbar, M., Arzani, H., Azimi, M.S., Mozafarian, V.A., Shad, G.H.A., Saghafi, F., Tavakoli, H., Naseri, S., 2011. Rangeland monitoring in the northeast of Iran. Jour. Range Desert Research, 18(2): 231-243. (In Persian).
Becker, K., Lohrmann, J., 1992. Feed selection by goats on tropical semi-humid rangeland. Small Ruminant Research 8 (4): 285-298.
Bijanzadeh, E., Emam, Y., Ebrahimie, E., 2010. Determining the most important features contributing to wheat grain yield using supervised feature selection model. Aust.  Jour. crop science 4(6): 402-407
Campbell, B.M., Gordon, I.J., Luckert, M.K., Petheram, L., Vetter, S., 2006. In search of optimal stocking regimes in semi-arid grazing lands: One size does not fit all. Ecological Economics 60 (1):75-85.
Cordova, F., Wallace, J.D., Pieper, R.D., 1978. Forage intake by grazing livestock: a review. Jour. Range Management 31(6): 430-438.
Erfanzadeh, R., Ashrafzadeh, M., Hosseini Kahnuj, S. H., Alizadeh, A., 2014. Preference Value Evaluation of Rangeland Plant Species for Kaboudeh Sheep. Jour. Rangeland Science, 4(3): 195-202.
Galt, D., Molinar, F., Navarro, J., Joseph, J., Holechek, J., 2000. Grazing capacity and stocking rate. Rangelands 22(6): 7-11
Habibian, S., Arzani, H., Javadi, S., Habibian, S.H., 2010. Comparison of two methods of preference value determination of plant species for sheep in semi-stepper rangelands in Fars province. Rangeland 4 (2):188-197. (In Persian).
Heady, H.F., 1964. Palatability of herbage and animal preference. Jour. Range Manag. 17(2):76-82
Holechek, J., Vavra, M., Pieper, R., 1984. Methods for determining the botanical composition, similarity, and overlap of range herbivore diets.425-471.
Hussain, F., Durrani, M., 2009. Nutritional evaluation of some forage plants from harboi rangeland, kalat, Pakistan. Pakistan Journal of Botany. 41(3):1137-1154.
Malechek, J. and Provenza, F. 1983. Feeding behavior and nutrition of goats on rangelands. World Animal Review (47): 38-48.
Meen, A., 2000. Grazing intensity and forage quality on the Arizona Strip. Rangelands 22(6):12-15.
Mirdavoodi, H.R., Sanadgol, A.A., 2009. Study of preference value of range plants in key ranges of Anjedan’s rangelands of Markazi province. Jour. Range Desert Research 16(2):190-199. (In Persian).
Ngwa, A., Pone, D., Mafeni, J., 2000. Feed selection and dietary preferences of forage by small ruminants grazing natural pastures in the Sahelian zone of Cameroon. Animal feed science and technology 88 (3): 253-266.
Rashtian, A., Mesdaghi, M., Beldaji, F., Barani, H., 2008. Investigation of preference value of Yazd Steppic Rangelands species. Iranian Jour. Agric  Natural Res Science 16 (3): 20-31. (In Persian).
Rogosic, J., Pfister, J., Provenza, F.D., Grbesa, D., 2006. Sheep and goat preference for and nutritional value of Mediterranean maquis shrubs. Small Ruminant Research 64(1): 169-179
Springfield, H., Reynolds, H., 1951. Grazing preferences of cattle for certain reseeding grasses. Jour. Range Management 4(2):83-87.
Vallentine, J. F., 2001. Grazing Management. Acad. Press,- 659 pages
Van Dyne, G.M., Brockington, N., Szocs, Z., Duek, J., Ribic, C., Breymeyer, A., 1980. Large herbivore subsystem. in Grasslands, systems analysis and man, (eds A.I. Breymeyer and G. M. Van Dyne), pp. 269-537, IBP 19, Cambridge University Press, Cambridge.
Van Dyne, G. M., and H. F. Heady. 1965. Botanical composition of sheep and cattle diets on a mature annual range. Journal of Agriculture Science Hilgardia 36: 465–468.
Vazquez, O., Smith, T., 2000. Factors affecting pasture intake and total dry matter intake in grazing dairy cows. Journal Dairy Science 83(10): 2301-2309.
Whittaker, R.H., Niering, W.A., 1975. Vegetation of the Santa Catalina Mountains, Arizona. V. Biomass, production, and diversity along the elevation gradient. Ecology 56(4):771-790.