The main objectives of this research on Sudanese sheep were to characterise performance and development of certain production traits. The findings have confirmed previous observations on the superiority of the Shugor in litter size over Dubasi and Watish under farm conditions. This should be taken into account in selection for development of dam lines. Age at first lambing was confounded with management. These influences have led to a late age at first lambing, whereas it is desirable that ewe lambs should have their first lambs when they are 16-18 months old. This could be attained by paying more attention to ewe lamb rearing and feeding, especially in the immediate postweaning period. Ewe lambs could be joined to rams in a separate flock and not included in adult ewe breeding programmes until after they have produced their first lamb. Lambing intervals recorded here are also quite long.
The current weight performance is considered poor and does not reflect the potential of these animals. Subtype differences are most marked for the Watish. Combination of Watish with either Dubasi or Shugor, however, has the advantage that the progeny develop heterotic effects in weight. Survivability at birth and thereafter should also be improved in both Shugor and Dubasi as the Watish has been shown to have the lowest mortality up to one year. Weight gains have not been satisfactory, which is most probably due to nutritional limitations, both during suckling and in the postweaning period. Correct feeding might alter the present picture in liveweight and weight gains.
Unless the very high mortality at all ages can be controlled, the possibilities for better productivity and development are poor. Nutritional, disease and management factors need proper investigation on the farm and within the breeders' flocks in the area in order to determine the major factors influencing mortality, and hence find solutions to this problem.
The results presented in this report indicate the need for the following investigations:
1. Flock health and mortality. A series of investigations on individual sheep and flock health should be carried out in collaboration with the Central Veterinary Research Laboratory in Khartoum. A disease survey in the local area and case studies in specific flocks should be undertaken.2. Investigations on early weaning. Weaning could be carried out at about eight weeks under improved nutritional conditions.
3. Additional selection and crossbreeding should be carried out to develop and test further this report's findings on crossbreeding. This may be extended to include other subtypes of sheep which have economic potential and presently contribute to the livestock trade.
4. Applied nutrition trials at all levels of feeding and for all aspects of sheep productivity, mainly by using forages and agricultural byproducts, should be conducted. In particular, the effects of pre- as opposed to postweaning supplementation and the relative merits of the particular periods of the dry season at which limited feed resources should be used, require detailed study.
