Determination of preference value of seven important range species in steppe region of Yazd province (Case study: Nodoshan rangelands)

To determine preference values of important range species in steppe rangelands of Yazd, direct time observation and bite-count techniques were employed in a mixed local herd. For each technique, 9 sheep and 9 goats were marked and chased for 15 minutes in three periods of grazing. The time of forage consumptions and the number of bits taken from seven important range species were recorded in three periods of grazing. To determine the range species composition based on production and canopy cover, 1-m2 plots were used. Factorial experiment in completely randomized design was used to compare preference values of seven important range species for each species of animal in three periods of grazing by using the recorded time and the counted bits. In both techniques, the variation of preference values of range species was similar for sheep and goat. Similarity of preference values for sheep and goat were above 80% and there were not significant differences in two methods (P<0.05). The precision of both techniques (direct time observation and bite-count) were same. In general, both techniques used during the grazing period had the similarity of 75%. As far as bite-count could be done with least available facilities, so this method is preferred to the direct time observation.