Les recherches sur la maîtrise de la reproduction des brebis et des chèvres ont abouti à des traitements hormonaux de synchronisation des chaleurs très largement utilisés. Leurs coûts sont supportés par la valeur ajoutée de la production laitière et le progrès génétique rapide permis par l’insémination artificielle associée à la synchronisation. Les éleveurs des pays en développement ne disposent pas des mêmes moyens financiers et des programmes de coopération conduits avec les chercheurs de ces pays portent sur des moyens moins coûteux de synchronisation, comme « l’effet mâle » qui ne nécessite que des manipulations de lots d’animaux, sans intervention hormonale. En France, l’effet mâle ne suscite d’intérêt que chez les éleveurs et professionnels ovins et caprins en Agriculture Biologique. Pendant plus de 20 ans, des programmes de coopération scientifique entre la France, la Tunisie et le Mexique ont permis de mieux connaître les mécanismes physiologiques de la réponse à l’effet mâle et les conditions de son utilisation. Ils ont produit de nombreuses publications et permis le développement de techniques durables de maîtrise de la reproduction, adoptées avec succès par les éleveurs tunisiens et mexicains. L’émergence récente de préoccupations environnementales a changé le point de vue des professionnels français, désormais plus soucieux de durabilité de leurs systèmes. Les informations accumulées lors de ces programmes internationaux de coopération sont maintenant utiles dans les systèmes d’élevage français et européens, pour accélérer la mise au point de nouvelles techniques alternatives à l’utilisation des traitements hormonaux.

Hormonal control of estrus in sheep and goats has encountered a tremendous success in farms of industrial countries. Their costs are supported by the added value of milk production and increase the genetic merit provided by artificial insemination associated with hormonal synchronization. On the contrary, small ruminant breeders from the developing world cannot benefit from these technologies; a part of the scientific programs within these countries are based on more sustainable techniques, such as the "male effect" which does not require anything except animal management. In France, the interest of professionals for the male effect has been limited to those engaged in organic farming. For 30 years, scientific programs of cooperation between Tunisia, Mexico and France have provided a better understanding of the physiological mechanisms underlying the females' response to the male effect and the adapted conditions of its utilization. They produced numerous publications and allowed the development of sustainable techniques now adopted by Tunisian and Mexican farmers. The recent emergence of environmental concerns has changed the point of view of French professionals, nowadays more concerned by sustainability. The information coming from these international programs can now be used in France and Europe to develop alternative techniques to hormonal treatments.

The “ram effect” has been an alternative method among many techniques to control the period of sexual activity in sheep. The objectives of this study were to (1) study the reproductive performances of the Barbarine breed in the spring, (2) to evaluate females’ response to the ram effect, and estimate the phenotypic and genetic parameters of the females’ response to the “ram effect”. A total of 16,150 matings of 4201 ewes recorded during a period of ten years in seven flocks was used in this study. Among these ewes 1335 have known parents and were born from 199 sires and 1053 dams. Four cyclicity traits were analyzed: spontaneous, normal, short and not answer to the ram effect. The main results show that approximately 30% of the females were cyclic out of season and more than 60% became cyclic with the “ram effect”. Flock, year and age at lambing had significant effects on the traits analyzed. A high negative phenotypic correlation of −0.75 was found between responses of normal cycles and responses of short cycle. The spontaneous ovarian activity in the spring was negatively correlated with the absence of response to a ram effect (rg=−0.44) and positively correlated to the response by a normal cycle (rg=0.63). The correlation between responses with the normal cycle and short cycle was highly negative (rg=−0.88). For all variables, heritability was low (from 0.03 to 0.09) but significantly different from 0 and repeatability was slightly higher and varied from 0.06 to 0.1. These results indicate the great opportunity offered by the Barbarine breed for out of season breeding.

Six healthy Maghrebi dairy camels at mid lactation were used in 2 trials to assess the camel training period for machine milking, and the short time effects of machine milking vs. hand milking on some milk production parameters and physicochemical characteristics in milk. Before the study, dams were reared in oasis intensive system and hand-milked twice. In trial 1 which lasted for 2 weeks, camels were trained for machine milking. In trial 2, camels were monitored during 2 successive weeks; on the first week they were hand-milked and on the second week, they were machine milked.Trial 1. Over days of training, the animals became less hostile and the total time between entering and exiting did not exceed 15 min. The lag time, after oxytocin injection, did not change and averaged 29.6 +/- 3.0 s. Nevertheless, milking time increased with the change of the milk production and averaged 7.5 +/- 0.4 min and 9.4 +/- 0.6 min, during the first and the second week, respectively.On the 2(nd) day of machine milking, daily milk yield decreased slightly (-6%) compared to the day (-2) before the start of machine milking. This production increased to 7.48 +/- 0.521 on day 13 of training. On the second week of the training period, no difference was observed between the daily milk yields. During training camels for machine milking, total milk solids, protein and ash contents did not vary. Milk fat was the most affected component, it decreased from 36.8 +/- 2.4 g/l 2 days before the start of machine milking until 28.7 +/- 1.8 g/l in day 10 of training period and returned to its initial value on day 13.Trial 2: Daily milk yield was 38% higher in machine than hand milking system. Milk secretion rate differed between the 2 milking systems. In the morning (8:00) as well in the afternoon (16:00), lag time was half shorter in machine milking (36.0 +/- 6.9 s) than in hand milking (58.0 +/- 4.0 s). However, milking time was longer in machine than in hand milking and ranged from 4.2 to 4.8 min and 2.6 to 3.2 min, respectively. Physical parameters of milk had higher values in machine than in hand milking system. However, in the morning, milk density was comparable between the 2 milking systems.

Sheep farming plays a vital role in food safety in Tunisia. This paper aims to reflect the current status of sheep farming through an analysis of their food availability and limits. A study of the possibilities for improving the local feeding resources is then made identifying the innovations in this field. Results show that the decrease in pasture areas is caused by the over-grazing, the frequent droughts and the expansion of cereal crops and tree plantations. Use of concentrates becomes more frequent in livestock industry. These concentrates are heavily based on imported ingredients whose prices have tripled over the last two decades. Consequently, a renewed interest has been given to the use of local feed resources and looking for alternatives such as their partial or total replacement of the imported raw materials. The use of the local barley and field beans in the sheep feeding could ensure acceptable animal performances. In the arid and semi-arid Tunisian zones, thousands of hectares of fodder shrubs have been established, especially spineless cactus, Atriplex nummularia and Acacia cyanophylla. Other innovations in animal feeding demonstrated the effectiveness of alternative feed resources like using feed blocks which could represent a promising nutritional tool especially when animals are grazing on poor pastures, the use of multi-purpose shrubs, or several agricultural and agro-industrial by-products (treated straws, cakes, pulps...). A lack of adequate co-ordination and synergy between the different stakeholders is inhibiting the progress and implementation of transversal approaches that are necessary for the delivery of integrated sustainable policies.

5 Abstract: Knowledge of factors affecting variation in birth weight is especially important given the relationship of birth weight with neonatal and adult health. This study examines the effects of age of dam, litter size and gender on birth weight in D'man lamb breed under accelerate lambing system (3 lambings/2 years) in the oases of Gabes. Data recorded between February 25th and May 15th 2008, concerned 91 lambs born at the Office d'Elevage et des Pâturages station in Chenchou located in southern Tunisia. Two- to 8-year-old ewes had a higher performance and dropped heavier lambs (P<0.05) that the old dams (more than 8 years old). The mean birth weight of single-born lambs (4.0 ± 1.0 kg) were significantly higher (P < 0.05) than those for twins (3.3 ± 0.5 kg), triplets (2.5 ± 0.4 kg) and quadruplets (2.3 ± 0.4 kg). Male lambs were heavier (P < 0.05) than female lambs (3.0 ± 0.6 kg vs. 2.7 ± 0.7 kg, respectively). Mortality in lambs occurs continually from birth to weaning (60 days of age) and it averaged 19.7% (n = 91). The third of this rate (33%) was observed in lambs issued from young dams (2 years of age), while 67% of mortality was equally distributed between lambs born from dams, 3-, 7- and 9-year-old. Lambs born in triplet litter had a significant (P < 0.05) higher mortality (12%) than those born in twin (2.2%) and quadruple litter (5.5%). A higher mortality rate was observed in females (13.17%) than in male lambs (6.58%). Dead lambs had less (P < 0.05) birth weight and daily body gain until 30 days of age than the survived ones (2.4 ± 0.4 kg vs. 3.0 ± 0.6 kg; 53 ± 34 g vs. 160 ± 52 g respectively). In conclusion, age of dam, litter size and gender significantly affect the birth weight which could be an important risk factor for D'man lamb mortality.

Le suivi de deux troupeaux caprins, conduits en extensif dans la montagne de la région aride Tunisienne pendant 4 campagnes, illustre des spécificités au niveau de la conduite et des performances individuelles. L'élevage caprin extensif de la montagne de Matmata joue un rôle socioéconomique important, en vertu de ses capacités de valorisation des ressources naturelles sans risques de dégradation de l'environnement. Les conditions climatiques de la montagne sont plus favorables à la production des caprins par rapport à celles observées au niveau de la côte et de la steppe. Le principal produit de cet élevage caprin est la viande du chevreau au lait. Estimée par l'équation de Gompertz, le poids du chevreau était de 2,8 kg à la naissance pour atteindre en moyenne 22,72 Kg avant l'âge de 8 mois; les performances de la croissance montrent des différences avec celles des chevreaux de la steppe et de la côte. La vitesse de la croissance diminue sensiblement après l'âge de 5 mois et le poids du chevreau reste évolue lentement pendant l'été. Le potentiel de production laitière, de la chèvre locale, s'avère limité et avec une large variabilité des performances individuelles. La moyenne journalière de production était inférieure à 200 g; alors que la production totale par lactation n'atteint pas les 25Kg de lait durant une période moyenne de 149 jours de lactation.

The Barbarine sheep is characterised by a fat-tail, whose mass varies between I and 4 kg. Its management is traditionally based on spring mating. The ability of this fat-tailed ewe to mobilise its body reserves has been demonstrated in lactation and the dry period by experimentally varying the food supply. The severely underfed ewe (200 g oat hay) can survive 161 days and lose 36% of its body weight (BW), with a change of 8.8 ka of dissected adipose tissue (AT) and 3.4 kg of muscle. It reached this stage with an empty BW of 24 kg containing 12% of AT. The fat tail exerts a role as a body reserve mainly through its mass rather than through its ability to be rapidly mobilised. In such Situations, plasma NEFA and 3-hydroxybutyrate concentrations are first almost doubled, then decline in permanently underfed ewes, showing the ability of Barbarine ewes to adjust their lipid metabolite concentration in order to limit the toxic effects of high concentrations and therefore prolong survival. By the end of a re-feeding period, Barbarine ewes returned to their initial BW, lipid and protein mass. This breed has a good fertility, which can, however, be depressed in cases of undernutrition. However, if the mating period is extended, the overall reproductive performance is generally satisfactory. Poor nutrition during pregnancy may reduce lamb birth weight and affect subsequent growth, however, in traditional conditions, ewe and lamb mortality rates are surprisingly low in this breed. In normal birth weighted lambs, the post-weaning growth performances of grazing lambs are moderate but in feedlot conditions the conversion rate is rather low and carcass adiposity is high. This review shows that the Barbarine sheep, and specially the ewe, is well adapted to the local conditions mainly because of its high fertility and its ability to deposit and mobilise body reserves.

The influence of the ram effect, starting at lambing, on the resumption of ovarian activity (determined by repeated laparoscopy observations) and oestrous behaviour of autumn-lambing Barbarine ewes was evaluated in 64 multiparous Barbarine ewes in the permanent presence (R; n=32) or totally isolated (NR; n=32) from rams. In the R treatment group, all ewes (100%) ovulated at least once before the 100-day postpartum period, compared to only 50% (P<0.05) in the NR ewes. The first postpartum ovulation occurred 20.3±9.7 days after lambing in ewes of the R treatment being shorter (P<0.05) than the mean interval of 50.4±28.7 days for ewes in the NR treatment. Resumption of postpartum ovarian activity was associated with abnormal ovarian cycles. Ewes (R) exposed to rams had a higher frequency of long cycles and tended to yield a reduced ovulation rate than ewes (NR) in isolation from rams (1.07±0.26% versus 1.20±0.40%). In the R treatment group, only 22 ewes of the 30 that ovulated (73%) displayed oestrus with a peak occurrence between days 30 and 40 after parturition. It is concluded that the continuous presence of rams could substantially hasten rebreeding in autumn postpartum Barbarine ewes.

Eighteen pregnant dromedary females (Camelus dromedarius) were used to determine the effect of concentrate supplement on growth and reproductive performances in peri-partum period. The females were divided into supplemented (n = 9; S) and unsupplemented (n = 9; C) experimental groups. All animals grazed, with one mature male, 7 to 8 hours per day on salty pasture rangelands. During night, they were kept in pen, where each female of group S received 4 kg per day of concentrate supplement during the last 3 months of gestation and 5 kg per day during the first 3 months post-partum. During the last 90 days of gestation daily body weight gain (DBG) was at least tenfold more important in group S than in group C (775 g vs. 72 g respectively). Supplementation affected birth weight of offspring (30.3 kg vs. 23.4 kg) and its DBG (806 g vs. 430 g) in group S and group C respectively. During the post-partum period, females in group S gained in weight (116 g per day) whereas females in group C lost more than 200 g per day. The mean post-partum interval to the first heat and the percentage of females in heat were 29.5 day and 44.4/ vs. 41.2 day and 71.4/ for the C and S groups, respectively. We conclude that under range conditions, dietary supplementation of dromedary during late pregnancy stage and post-partum period improves productive and reproductive parameters.