This study was conducted in Alzzazah area which lies approximately 25 km East of El-Dmazein city, the capital of the Blue Nile State, Sudan. This study was carried out at the end of the autumn 2015. The aim of the study was to evaluate the impacts of continuous grazing on the rangeland of the study area. To determine this effect, two range sites were selected to represent the rangeland in the study area; a grazed one and a protected one by enclosure. At each site, eight line transects were systematicly distributed. Parker loop method was used to determine botanical composition and ground cover. Quadrate method was applied to determine plant density, frequency, biomass production and carrying capacity. The obtained data were organized and analyzed using standard range management equations and SAS statistical package. The result showed that the continuous grazing increased the bare soil percentage and decreased the vegetation cover. Also, it had negative impacts on botanical composition, biomass productivity and range carrying capacity. It was concluded that continuous grazing has a negative impact; it led to change the botanical composition of range plants of undesirable species with low nutritive value. So it can be considered as one of the main factors responsible of rangeland degradation in the study area. تفاصيل المقالة

Fodder trees and shrubs are crucial sources of animal feed in Sudan, particularly in arid and semi-arid areas. This is because they can fill up the feed gaps in the summer period when grassland growth is limited due to unfavorable weather conditions. The study was conducted in Elnour forest-southeastern Sudan in 2015, which is dominated by Acacia seyal. The objectives of this study were to estimate the browse productivity, and to establish relationships with the crown area for Acacia seyal. The twig-count method described in this study converts a count of twigs to weight of browse by use of an average weight per twig for individual trees. Regression analysis was used to establish relationships between browse biomass and crown area. The average available browse (8.1 kg/ha) and tree density (162 tree/ha) for Acacia seyal was low in the study area that makes the density as the main factor that determine the amount of available browse/ha. Strong positive correlations were found between browse biomass productivity (available and total browse) and crown area with average values of 0.86 and 0.90, respectively. The study concluded that crown area as the main parameters used for predicting the browse biomass productivity. It is recommended that more effort be made to expand the use of more species to investigate the relationships between browse biomass productivity and growth parameters. تفاصيل المقالة

The study was conducted to determine the plants preference by goats grazing at Central Darfur State, Sudan in 2016. The objective was to identify desirable plants that would assist in range rehabilitation. Five mature female goats were used to determine diet selection using the bite count technique. The total number of bites from each plant species was recorded and the selected diet and preference indices were calculated. It was found that forbs constituted 52.6% of the diet of goats followed by trees and shrubs (43.6%) and then grasses (3.6%). Among the forbs Ipomoea sinensis (Desr.), Kohautia aspera and Haemanthus multiflorus were the most selected forbs with average values of 7.17%, 5.53% and 4.06% respectively. Faidherbia albida, Ziziphus spina-christi and Albizia amara were the most selected trees with average values of 18.29%, 7.77% and 7.66% respectively. The grass species that appeared most in the diet of goats was Pennisetum pedicellatum (3.53%). In this study forbs had higher Relative Preference Indices (RPI) than grasses. The higher values of RPI in forbs as Abelmoschus esculentus, Kohautia aspera, Commelina kotschyi, Portulaca quadrifida, Talinum portulacifolium and Setaria acromelaena were 25.2 7.9, 3.7, 3.68, 3.64 and 3.42, respectively. Plants with higher RPI were suggested for reseeding rehabilitation projects. These findings may be considered as a basis for an informed management system in the study area which will be invaluable in developing sustainable management strategies. تفاصيل المقالة