Effects of range condition on the temporal diet selection by goats in steppe rangelands of Iran

Document Type: Research Paper

Authors

1 Assistant Professor, Yazd Agricultural and Natural resources Research Center, Yazd, Iran

2 Assistant Professor, Faculty of Natural Resources and Environment, Ferdowsi University of Mashhad, Mashhad, Iran

3 Senior Expert of Range Management, Yazd Agricultural and Natural resources Research Center, Yazd, Iran

Abstract

One of the key factors in managing a rangeland is to determine the relative preference of its major plant species by the
grazing livestock. Preference value of each plant species is affected by plant type, companion plants, availability by
animals, phenological stage, climate condition, and the livestock species. We investigated the grazing behaviour of a
native goat (Garizi) in the steppe rangelands of Iran, from May to November 2004. The study was conducted within or
outside of an enclosure, representing a Good Condition (GC) or a Poor Condition (PC) rangeland, respectively. Flocks of
six goats were selected randomly and their grazing behaviour was monitored by chronometers. Grazing preference was
considered as the time goats had spent for grazing each plant species. The grazing season was divided into 4 grazing
periods, 45 days each. Data recording in the GC and PC sites was repeated 3 times during each grazing period. The
experiment was designed as the completely randomized blocks. In the GC site, grazing pressure on the perennial grass
Stipa barbata and the perennial chenopod Salsola rigida was low at the beginning of the grazing period, but it was
increased towards the end of the grazing season. In the PC site, the main grazing pressure was on noxious plants such as
Scariola orientalis, Launaea acanthoides, and Cousinia deserti. For both GC and PC sites, the time of grazing had
significant influences on relative abundances of annual plants and plant litter, which subsequently changed diet selection
by the Garizi goat.
One of the key factors in managing a rangeland is to determine the relative preference of its major plant species by the
grazing livestock. Preference value of each plant species is affected by plant type, companion plants, availability by
animals, phenological stage, climate condition, and the livestock species. We investigated the grazing behaviour of a
native goat (Garizi) in the steppe rangelands of Iran, from May to November 2004. The study was conducted within or
outside of an enclosure, representing a Good Condition (GC) or a Poor Condition (PC) rangeland, respectively. Flocks of
six goats were selected randomly and their grazing behaviour was monitored by chronometers. Grazing preference was
considered as the time goats had spent for grazing each plant species. The grazing season was divided into 4 grazing
periods, 45 days each. Data recording in the GC and PC sites was repeated 3 times during each grazing period. The
experiment was designed as the completely randomized blocks. In the GC site, grazing pressure on the perennial grass
Stipa barbata and the perennial chenopod Salsola rigida was low at the beginning of the grazing period, but it was
increased towards the end of the grazing season. In the PC site, the main grazing pressure was on noxious plants such as
Scariola orientalis, Launaea acanthoides, and Cousinia deserti. For both GC and PC sites, the time of grazing had
significant influences on relative abundances of annual plants and plant litter, which subsequently changed diet selection
by the Garizi goat.

Keywords