Some production characteristics of Sudan Desert sheep under range conditions in north Kordofan, Sudan.

The records on the flocks of sheep at El-Obeid Research Station during 1988-1990 were analysed using least-squares mixed-model procedures. The objective was to study some production characteristics of Sudan Desert sheep in North Kordofan, Sudan, in relation to the seasonal variation and husbandry systems. No significant differences (p > 0.05) were found between sedentary and nomadic flocks in the number of ewes serviced and the conception, lambing or abortion rates. Mortality rates were significantly (p < 0.05) higher in the nomadic flock. The breeding season had a significant effect on all the parameters measured. Higher conception (p < 0.05) and lambing (p < 0.01) rates were recorded for the rainy and late dry seasons. However, the highest ewe mortality (p < 0.01) was in the rainy season. The highest (p < 0.01) lamb weights at birth and at 30 days of age were recorded under the nomadic system. None the less, lambs kept under the sedentary system had somewhat higher weight gains from 60 to 150 days of age. Lambs born during the rainy season had the highest birth weights (p < 0.05) and the highest weight at 30 days of age. However, the live weights from 60 to 150 days of age were significantly higher in lambs born in the late dry season. The highest lamb mortality was recorded in the lambs born in the rainy season. Lambs born under the nomadic system and during the rainy season had the highest (p < 0.05) weights at 30 and 60 days of age, and also higher (p < 0.01) mortality rates compared to the other flock x season combinations. It was concluded that the production characteristics of Sudan Desert sheep reflect the seasonal nutritional status and husbandry system. The effects of supplementary feeding on breeding and pregnant ewes, and on the performance of weaned lambs in the area should be studied. Moreover, the socioeconomic factors governing mobility in nomadic flocks should be thoroughly investigated.