The fat-tailed Barbary sheep is the typical sheep of Tunisia and Libya. It does not exist in Algeria, Morocco and Egypt. It accounts for about 80 percent of the total number of sheep in Tunisia (3 400 000 adult females) and 95 percent of Libyan sheep (2 000 000 head). In Tunisia, the fat-tailed sheep have been present since Carthaginian times and may have been brought from Syria by the Phoenicians (Mason, 1967). In fact, as depicted in Phoenician and Roman monuments it appears that this kind of fat-tailed sheep was introduced in Tunisia by the Phoenicians about 400 B.C. They were exploited in the country until 300 A.D. when they were replaced by a very long thin-tailed breed. The fat-tailed sheep were not reintroduced in Tunisia until 900 A.D. with the Arab invasion (Sarson, 1973). In Libya, the fat-tailed sheep came from Egypt about 1000 B.C. (Mason, 1967). It is now thought that the Barbary sheep were introduced in both Tunisia and Libya at the same time and possibly under the same conditions, but it is certain that the Barbary sheep breed originates from the Asiatic steppes.
Locally, the fat-tailed Barbary sheep are called Nejdi or Arabi sheep. The term "Barbary breed" is the European nomenclature attributed to these fat-tailed sheep originating from the Berbers, the ancient inhabitants of North Africa.
The Barbary is a robust and vigorous animal. It is characterized by its fat tail (Figure 1.1) which is a bilobed scak of fat due to an accumulation of reserve fats on each side of the coccygeal vertebra (Figure 1.2). Owing to these adipose reserves, the animals of this breed are very resistant to poor nutrition to which they are frequently submitted in Libya and the centre and south of Tunisia. The weight of the fat tail varies greatly and in some animals with a good body condition it can reach up to 15 percent of the carcass weight. The Barbary sheep is present in all regions of Tunisia from the Sahara to the north coast, but is mainly found in the central region between. Zaghouan and Gafsa. In Libya, it is found particularly in the steppes along the north coast.
The Barbary is a very hardy sheep. It is also longlegged and a good walker. The height of adult animals ranges from 60 to 80 cm in males and from 55 to 70 cm in females. Liveweight ia also varied according to regions and feeding conditions and ranges from 45 to 85 g in rams and from 28 to 65 g in ewes.
The colour of the fleece is always white but the head can be red (Figure 2) or black (Figure 3). In this latter case, animals are less sensitive to photosensitization caused by Hypericum consumption. The fleece is regular, open or semi-closed and its mean weight is 1.8 g in ewes and 2.5 g in rams. The head and legs are bare. The wool varies from coarse and kempy to medium-fine and wavy with a quality number of 48/50' to 50/56' (Mason, 1967). This wool is used for the artisanal manufacture of carpets and rugs.
The forehead is flat or slightly concave and horns are usually absent in both males and females. The ears are long, wide and pendulous.
In spite of its importance, the sheep sector has largely maintained an exclusively extensive character. Livestock are still considered, particularly in private farms, a means of accumulating wealth. This explains the high rate of unproductive animals sometimes found in the flocks.
Flock feeding is based essentially on natural vegetation resulting from natural pastures and fallows. In summer, feed comes only from cereal stubble and/or dry vegetation. As rainfall is irregular, these feed resources are often quantitatively and qualitatively insufficient and animals often suffer from chronic undernutrition. For this reason, farmers regularly rent pasture areas, fallows and/or cereal stubble for their flocks, especially in summer and autumn, the two most difficult seasons.
The addition of hay, straw and/or concentrates to the diet is often rare and irregular. It is done only during the very dry periods to reduce mortality rates.
Rams are always kept in the flock and the mating season is very long, from April to November. Thus, lambings occur usually between September and March with two peaks in October-November and February-March. Lambs are weaned at 4 to 5 months of age with liveweight ranging from 20 to 30 g. The fat-tail of ewes represents a natural obstacle to mating. Thus, the intervention of the shepherd at this moment is essential to facilitate mating by lifting the tail of oestrous females to one side.
The culling of animals is not always performed at the right time. In fact, old, unproductive or low productive sheep can represent more than 35 percent of many flocks. Further prophylactic measures are not systematically undertaken. The main diseases encountered are gastrointestinal and pulmonary strongylosis, enterotoxoemia and scabies.
The fertility rate of the 25 flocks surveyed over a 15-year period varied from 84 to 98 percent with a mean of 89 percent (Khaldi, 1986).
The prolificacy rate of these flocks ranged during the same period from 102 to 139 percent with a mean value of 117 percent. Although the Barbary is not a highly prolific sheep, it has been demonstrated that prolificacy rate can reach 144 percent in spring lambing ewes, 145 percent in well-flushed ewes, 196 percent in ewes treated with 400 UI of PMSG and 172 percent (160-181 percent) in females selected for prolificacy (Khaldi, unpublished data).
Birth weight of Barbary sheep calculated during a period of 20 years at the Experimental Station of Ousseltia in central Tunisia varied from 3.1 to 3.6 g according to sex and litter size (Khaldi, 1980). On the other hand, growth rate between the 10th and the 30th days of age ranged between 170 and 220 g/day and between 150 and 180 g/day (Table 1) for single males, single females and twins (Khaldi, 1980).
Table 1: Birth weight (g) and growth rate (g/day) of Barbary lambs
| Single males | Single females | Twins | |
| Birth weight (kg) | 3.6 | 3.4 | 3.1 |
| At 10-30 d (g) | 220 | 200 | 170 |
| At 30-90 d (g) | 180 | 170 | 150 |
In a recent study, Khaldi et al. (1987) analysed the gentlc and phenotypic variation factors of the growth parameters of Barbary lambs. These lambs issued from the flock at Ousseltia Station during the period 1963-79. The total number of lambs used was 3 653. The variables analysed were birth weight and weight at 10, 30 and 90 days of age and growth rate between 10 and 30 days and between 30 and 90 days.
The results of the study show that under the harsh conditions of central Tunisia, all these parameters are closely related to the effect of the year (Figures 5, 6, 7). Because of these harsh environmental conditions, lamb growth is below their real potential since growth rates of 250 g/day are often obtained under experimental conditions or in rainy years (Khaldi, 1984).
The growth potential of lambs is difficult to assess during the suckling period as it is closely related to pregnancy and milk production of the ewe for the first three months. Thus, selection for growth will depend on greatly changed production methods (Khaldi, 1979, 1983, 1984).
The mortality rate of lambs in the study varied from 0 to 34 percent according to year and management conditions. The mortality rate of adult animals ranged between 0 and 21 percent. The mean mortality rate of all the flocks was 8 and 5 percent for the two categories of animals respectively. It is evident that these two parameters are significantly higher in dry years than when rainfall does not represent a limiting factor.
In the Experimental Stations of the National Institute of Agricultural Research of Tunisia, the mortality rate of lambs and adults does not exceed 5 percent whatever the annual rainfall may be (Khaldi, unpublished data). This result is evidently related to forage availability.
