Barbarine Sheep Research Articles

Estimation of Genetic Parameters for Litter Size and Growth Traits in a Prolific Line of Tunisian Barbarine Sheep

This study aimed to assess genetic parameters for ewe productivity in a Tunisian Barbarine sheep line. The traits studied were litter size (LS), birth weight (BW), weight at 90 days (W90), and average daily gain between 10 and 30 days (ADG13). A total of 3804 growth and 2726 lambing records were used. Bivariate linear and threshold animal models were fitted and analyzed using the Gibbs sampling methodology. Heritabilities for LS obtained with univariate threshold, bivariate linear, and threshold models were around 0.15, higher than the estimate obtained by a univariate linear model (0.09 ± 0.03). Direct heritability for growth traits remained consistent across models, except for W90 in the bivariate linear threshold model. Maternal heritability for growth traits was higher than direct heritability, ranging from 0.07 to 0.15, except for BW. The covariances between the direct and maternal effects of growth traits were slightly negative. Repeatability oscillated between 0.16 and 0.62. Direct genetic correlations between LS and the other traits were negative, varying from −0.18 (LS-BW) to −0.83 (LS-W90). Our results suggest that the threshold model may be the most appropriate for LS. A selection index including LS and growth traits may be proposed for routine genetic evaluation in this population.

Repeated Cross-Sectional Survey of Ectoparasites in Sheep from Central Tunisia: Does Low Prevalence Indicate Good Hygiene or Resistance to Ectoparasites?

Sheep ectoparasites such as chewing lice, fleas and ticks are serious constraints to sheep productivity and are the cause of skin lesions in animals that decrease their market value. This study aims at investigating the ectoparasite fauna infesting small ruminants in the district of Sidi Bouzid (central Tunisia). A total of 1243 Barbarine and Queue Fine de l'Ouest (QFO) sheep were examined every two months for one year. Of the total animals examined, 74 were infested by at least 1 parasite group (5.95%). Three ectoparasite groups were identified as Psoroptes ovis (0.48%; 6/1243), ticks (5.3%; n = 66/1243) and one specimen of Ctenocephalides canis (0.08%; n = 1/1243). The most abundant tick among the 358 specimens was Rhipicephalus sanguineus sensu lato (n = 337; 94.1%), followed by Hyalomma impeltatum (n = 7/358; 1.9%), H. dromedarii (n = 7/358; 1.9%), H. excavatum (n = 5/358; 1.4%) and only two specimens of H. scupense (n = 2/358; 0.55%). The sheep herds showed low infestation prevalence by ectoparasite over the year, with a significant difference according to the seasons (p < 0.05). A higher infestation prevalence was recorded in March (14.36%). Barbarine sheep breed showed significantly higher infestation prevalence (16.8%) compared to QFO (0.8%) (p < 0.01). There were no differences in infestation prevalence according to sex of the animal or age groups. Knowledge of the ectoparasite population harboured by sheep, its activity dynamics and risk factors is required to develop effective ectoparasite control options. The low prevalence of ectoparasite infestation in sheep reported here may be due to possible genetic resistance or simply to successful hygiene measures implemented by farmers.

Insight into the current genomic diversity, conservation status and population structure of Tunisian Barbarine sheep breed.

Local livestock breeds play a crucial role in global biodiversity, connecting natural and human-influenced environments and contributing significantly to ecosystem services. While commercial breeds dominate industrial systems, local livestock breeds in developing countries, like Barbarine sheep in Tunisia, are vital for food security and community maintenance. The Tunisian Barbarine sheep, known for its adaptability and distinctive fat-tailed morphology, faces challenges due to historical crossbreeding. In this study, the Illumina Ovine SNP50K BeadChip array was used to perform a genome-wide characterization of Tunisian Barbarine sheep to investigate its genetic diversity, the genome structure, and the relationship within the context of Mediterranean breeds. The results show moderate genetic diversity and low inbreeding. Runs of Homozygosity analysis find genomic regions linked to important traits, including fat tail characteristics. Genomic relationship analysis shows proximity to Algerian thin-tailed breeds, suggesting crossbreeding impacts. Admixture analysis reveals unique genetic patterns, emphasizing the Tunisian Barbarine's identity within the Mediterranean context and its closeness to African breeds. Current results represent a starting point for the creation of monitoring and conservation plans. In summary, despite genetic dilution due to crossbreeding, the identification of genomic regions offers crucial insights for conservation. The study confirms the importance of preserving unique genetic characteristics of local breeds, particularly in the face of ongoing crossbreeding practices and environmental challenges. These findings contribute valuable insights for the sustainable management of this unique genetic reservoir, supporting local economies and preserving sheep species biodiversity.

Characterization of the First Case of Classical Scrapie in a Sheep in Tunisia

Classical scrapie is a contagious prion disease of sheep and goats. It is endemic in many countries in Europe, North America, and Asia. In Africa, imported scrapie cases have been described in South Africa and Kenia in the past. More recently, several cases have been reported from different regions of Libya, based on clinical signs and histological lesions. Here, we report the results of thorough investigations carried out on a suspect case of scrapie in a 6-year-old Barbarine sheep, born, and bred in Tunisia, showing behavioral changes, weight loss, itching, skin lesions, wool loss, and motor incoordination. Histopathology and immunohistochemistry revealed spongiform change in several brain areas with associated pathological prion protein deposition. Western blotting confirmed the diagnosis and showed a classical scrapie-like molecular pattern of PrPres, different from atypical scrapie and bovine spongiform encephalopathy (BSE) in small ruminants. Sequence analysis of the prion protein gene showed that the animal carried the ARQ/ARQ genotype, one of the most susceptible to classical scrapie. The inoculation of sheep brain homogenate in a susceptible rodent model proved the experimental transmissibility of the disease. These results demonstrate the circulation of classical scrapie in Tunisia and confirm its presence in North Africa, indicating the need to improve epidemiological surveillance and diagnostic capacity for prion diseases in the region.

Marker-assisted introgression of fecundity mutation into Barbarine sheep breed under low input production system

Fecundity gene introgression has become an economical method to improve sheep prolificacy in developing countries. The FecXBar and FecGHmutations are variants of the BMP15 and GDF9sheep genes,respectively, identified in Tunisian Barbarine sheep prolific line "W-INRAT," created through a prolificacy-based selection program. The firstmutation caused increased prolificacy in heterozygous state and sterility in homozygous ewes. The aim of this work was to increase the number of effective carriers by the introgression of fecundity mutation into non-carrier conventional flocks based on a marker-assisted breeding program. The genotyping was carried out to follow up on the segregation of prolificacy mutation. The conventional ewes, raised in state farms of Tunisia and inseminated by "W-INRAT" rams, yielded 100% carriers females at heterozygous state. These females were selected to be inseminated with conventional rams and produced carriers' lambs with 66.7% males and 33.3% females. The prolific males will be kept in breeding centers to disseminate the fecundity mutation in commercial flocks. This approach facilitates the dissemination of fecundity genes and contributes to livelihood improvement in communities raising Barbarine sheep.

Digestibility, nitrogen balance and weight gain in sheep fed with diets supplemented with different seaweeds

Three completely randomised design experiments examined the effects of the inclusion of three seaweed species (Ruppia sp., Ulva sp. or Chaetomorpha sp.) into the diet on digestibility and nitrogen balance in Barbarine sheep. Diets were composed of oat hay ad libitum supplemented with 600 g of concentrate. Seaweeds were incorporated into the concentrate at increasing levels (0, 200, 300 or 400 g seaweed kg−1 concentrate, dry matter (DM) basis) in replacement of other ingredients. Feed intake and water consumption were increased (P 0.001) organic matter digestibility from 0.637 with the control diet to 0.599 with the diet containing 400 g Ulva kg−1 concentrate. In all the experiments, nitrogen balance was positive and there were no differences among levels of seaweed supplementation in N retention or daily weight gain. These results suggest that seaweeds such as Ruppia, Ulva or Chaetomorpha can be incorporated into sheep concentrates up to 30% (DM basis) without adverse effects on feed digestibility or growth performance.

Differences in tick infestation of Tunisian sheep breeds.

Different infestation patterns by ixodid ticks were studied in three sheep breeds in Tunisia: Barbarine, Queue Fine de l'Ouest and their cross-bred animals. During one year, 700 sheep were monitored and examined for tick infestation. A total of 722 ticks were collected from sheep ears. The most frequent tick species was by far Rhipicephalus sanguineus sensu lato (99%) and there were few specimens of Rhipicephalus bursa (1%) (p < 0.001). Overall infestation prevalence was estimated at 10.4%. The lowest infestation prevalence was in Barbarine sheep (7.3%), followed by Queue Fine de l'Ouest (16.7%) and the highest prevalence was in cross-bred sheep (19.1%) (p < 0.001). Mean overall infestation intensity was 1.6 ticks/sheep: lowest in Barbarine (1.4), followed by Queue Fine de l'Ouest (1.7) and cross-bred sheep (1.8). Similarly, abundance was lowest in Barbarine sheep (0.1), and was 0.3 in Queue Fine de l'Ouest and cross-bred animals. The results demonstrated a reduced infestation, possibly due to reduced attractiveness and/or increased resistance to tick infestation, of the Barbarine breed compared with the other two breeds. Further behavioural, genetic and molecular studies are needed to explain the mechanisms for the lower infestation indicators.

First detection and molecular identification of Sarcocystis spp. in small ruminants in North-West Tunisia.

Sarcocystosis is a parasitic disease caused by varying Sarcocystis species infecting humans and animals. It is commonly found in small ruminants causing pathogenic effects. This contributes to detrimental economic loss for local farmers and the local economy due this disease. Although the distribution of Sarcocystis can be found all over the world, the species infecting small ruminants in Tunisia is still unknown. Through this study, we aim to estimate the molecular prevalence of natural infection with Sarcocystis spp. in sheep and goats using molecular identification. Also, phylogenetic analyses were used to identify the different species of this parasite infecting small ruminants in northern Tunisia for the first time. DNA was extracted from 198 and 121, sheep and goats meat samples, respectively. The molecular prevalence of Sarcocystis spp. in sheep and goats was 58.6% (116/198) and 50.4% (61/121), respectively. Compared to the Noire de Thibar and cross-breeds, the Barbarine sheep had the highest infection prevalence (63.4%) (p=.004). Five of the 116 positive samples were sequenced identifying Sarcocystis tenella from sheep. For goats, the sequencing results showed that five positive PCR products belonged to Sarcocystis capracanis species.

FecXBar a Novel BMP15 mutation responsible for prolificacy and female sterility in Tunisian Barbarine Sheep

BackgroundNaturally occurring mutations in growth and differentiation factor 9 (GDF9) or bone morphogenetic protein 15 (BMP15) genes are associated with increased ovulation rate (OR) and litter size (LS) but also sterility. Observing the Tunisian Barbarine ewes of the “W” flock selected for improved prolificacy, we found prolific and infertile ewes with streaky ovaries. Blood genomic DNA was extracted from a subset of low-ovulating, prolific and infertile ewes of the “W” flock, and the entire coding sequences of GDF9 and BMP15 were sequenced.ResultsWe evidenced a novel polymorphism in the exon 1 of the BMP15 gene associated with increased prolificacy and sterility. This novel mutation called FecXBar is a composite polymorphism associating a single nucleotide substitution (c.301G > T), a 3 bp deletion (c.302_304delCTA) and a C insertion (c.310insC) in the ovine BMP15 cDNA leading to a frame shift at protein position 101. Calculated in the “W” flock, the FecXBar allele increased OR by 0.7 ova and LS by 0.3 lambs (p = 0.08). As for already identified mutations, homozygous females carrying FecXBar exhibited streaky ovaries with a blockade at the primary stage of folliculogenesis as shown by histochemistry.ConclusionsOur investigation demonstrates a new mutation in the BMP15 gene providing a valuable genetic tool to control fecundity in Tunisian Barbarine, usable for diffusion program into conventional flocks looking for prolificacy improvement.

Effect of sodium chloride, sodium sulfate or sodium nitrite in drinking water on intake, digestion, growth rate, carcass traits and meat quality of Barbarine lamb

The 79day-experiment reported herein was conducted to determine through a completely randomized design the effects of the enrichment of drinking water for lamb with sodium chloride (NaCl), sodium sulfate (Na2SO4), or sodium nitrite (NaNO2) on water and feed intakes, apparent diet digestibility, nitrogen balance, microbial nitrogen supply, rumen fermentation (pH, ammonia nitrogen and protozoa concentrations), blood metabolites, carcass traits and meat quality (i.e. ultimate pH, cooking loss, and fatty acids (FA) profile). Four groups of eight Barbarine lamb each (initial BW 21.1±2.4kg, 5–6-month old) were housed in individual boxes and received oat hay ad libitum and 400g concentrate. Each group was assigned randomly to one of the following treatments: ad libitum access to fresh water (control, group 1) or to fresh water enriched with either 7g NaCl/L (group 2), or 2g Na2SO4/L (group 3) or 40mg NaNO2/L (group 4). Lambs having access to salt-enriched water consumed more water than control lambs. Such effect was important (P<0.05) in group 2 (4.6 vs 2.48l/day). Compared to control group, the three sources of salt administrated in water had no effect (P>0.05) on diet intake and apparent digestibility, N retention and microbial N supply. Rumen pH, ammonia-N and protozoa remained unchanged (P>0.05) with the consumption of saline water. The lack of variation of diet intake and digestibility and rumen fermentation could justify the absence of significant variation of the growth rate of lambs (44–63g/day). Serum creatinine increased (P<0.05) with the administration of the three salts in drinking water. Serum glucose was higher (P<0.001) in lamb assigned to Na2SO4 and NaNO2 treatments. Nitrite treatment (40mg NaNO2/L) reduced (P=0.034) the concentration of triglycerides in the blood. The enrichment of water with the three sources of salts had no adverse effect on carcass yield and the FA profile of lamb meat, except for iso-heptadecanoic acid (C17:0 iso) which was higher (P=0.024) in the meat of lambs in group 3 than in the meat of control group. The proportion of 10-heptadecenoic acid (C17:1(n-7)) in the meat of lambs drinking NaNO2-enriched water was 25–30% lower (P=0.041) than that of the three other groups. The ratio Omega 6 to Omega 3 was similar among the four lamb groups (4.68–5.01). It is concluded that the doses and types of salts intentionally used in the present study to reflect water quality in some Tunisian zones home to Barbarine sheep had no effect on lamb’s growth, carcass traits and meat quality. However, the increased creatinine and reduced triglycerides in the blood justify the need to emphasize further investigations on the effect of these salts on lamb’s health.

English

The integration of livestock in the practices of conservation agriculture (CA) was assessed in Tunisian semi-arid conditions. Forty five Barbarine lambs (aged 220 &plusmn; 10 days, average body weight 20 &plusmn; 2.5 kg) were used in a performance trial, carried out in the experimental station of INRAT. During the experiment, lambs were grazing on a plot of barley stubble cultivated according to CA was divided into 6 fenced equal subplots and to each subplot was assigned a stocking rate of animals (15 and 30 lambs per hectare, SR15 and SR30 respectively). The biomass of stubble and its botanical composition were estimated 2 times, using quadrats sampling technique. Live weight was determined 3 times after the start of the experiment (three 15-days successive periods) to calculate live weight gain (LWG) and daily live weight gain (DLWG). The amount of biomass varied (P &lt;0.05) from 2204 to 2067 kg DM / ha for SR15 plots and from 2404 to 1826.5 kg DM/ha for SR30 ones. This decrease was higher with SR30 (P&lt;0.05). Heads proportion decreased first, then leaves and finally stems. Biomass chemical composition declined with sampling period. During the first grazing period, lambs assigned to both treatments lost LW (P&lt;0.001), mainly SR30 lambs as compared to SR15 (P&lt;0.05, -610 and -110 g, respectively). The same trend was observed in DLWG (P&lt;0.05). In the second period, the two groups exhibited similar LWG (about 2 kg) and DLWG (about 171 g/d). In the third period, SR15 lambs maintained their body weight, while SR30 group lost (P&lt;0.001) about 400 g comparatively to the second period. It was concluded that under the studied feeding system, stubble grazing without supplementation allowed Barbarine sheep to maintain body conditions. Key words: Lambs, barley stubble, stocking rate, conservation agriculture.

Effect of Pre-Mating Water Deprivation on Ovarian Activity and on Reproductive Traits of Mature Barbarine Ewes during Summer Season

mature Barbarine ewes were used to study the effect of water deprivation on feed intake and reproductive traits. Animals were allocated to two groups of 30 animals each. Control ewes (C) had free access to water while deprived ewes (D) were watered every 3 days during 8 weeks in mating period.Feed and water intake were recorded daily for each animal. Body weight was measured every week. Rectal temperature was also measured every week of the trial on the 1 st , 2 nd and the 3 rd day of water deprivation. Ovulation rate was determined by endoscopy 12 days after oestrus behaviour. Lambing rate and litter size were calculated. Body weight and feed intake were not affected (P>0.05) by water deprivation. However water intake increase in deprived ewes (P<0.01). Reproductive results showed that water deprivation did not affect significantly either the percentage of females in oestrus during the 3 days following ram introduction nor the return rate (80% vs 90% and 13% vs 10% respectively for control and water deprivation groups). Moreover ovulation rate, fertility and litter size were similar for both groups (110% vs 130%, 93.3% vs 100% and 103% vs 123% respectively for control and water deprivation groups). These results indicate the wide adaptation of Barbarine sheep for water deprivation as indicated by the absence of significant negative effects on reproductive performances.

English

This study investigates the genetic diversity and the structure of the most dominant native fat-tailed Tunisian sheep breed (Barbarine, BAR) using microsatellite markers. Blood samples from 183 BAR animals, belonging to 4 subpopulations according to phenotypic traits, were collected across all regions in Tunisia. BAR animals and 31 Appenninica Italian sheep breed (APP) used as an out-group were genotyped at 17 microsatellites loci. A total of 270 alleles were identified with average gene diversity equal to 0.812. The mean observed heterozygosity (0.745) and allelic richness (8.09) estimates were high within BAR breed highlighting notable levels of genetic diversity. The low FIS (0.078) and FIT (0.084) values indicate low level of inbreeding within this breed while a low FST estimate (0.007) shows that the subpopulations are not genetically differentiated. The clustering analysis performed with &lsquo;structure&rsquo; detected the absence of substructures and the clear uniqueness of the BAR. Tomiuk and Loeschcke&rsquo;s DTL genetic distance values confirmed the distinction between APP and BAR breeds. Results arising from our microsatellites analysis represent a starting point for the valorization of this indigenous Tunisian sheep breed. A suggestion was made to monitor its genetic variability and for the preservation of this breed for the next generations. &nbsp; Key words: Tunisian Barbarine sheep breed, microsatellite markers, genetic variability, population structure.

Prolific strains of Barbarine sheep are characterized by increased ovulation rate due to extended period of ovulatory follicle recruitment and co-dominance effects

Preovulatory follicle dynamics and plasma oestradiol around the time of onset of oestrus as well as ovulation rate were assessed, during non-breeding season, in prolific (W; n=20) and non prolific (AB; n=20) strains of the Barbarine sheep. Oestrus cycles were synchronized with progestagen sponges for 14 days followed by introduction of rams. Transrectal ultrasonographic monitoring of the ovaries was carried out from the day of pessaries removal up to oestrous exhibition. Blood samples were collected every 4h and were analyzed for plasma concentrations of oestradiol by radioimmunoassay. Laparoscopy was performed 11 days after introduction of rams to assess number of corpora lutea (CL). Results indicate that along the first 5 days after introduction of rams, 20 and 14 ewes of respectively the AB and W ewes exhibited oestrus (P<0.01). Ewes of the W strain had more medium (3.5–5.4mm) follicles than AB ones during the follicular phase; the difference being significant (P<0.01) 24h before oestrus. The number of medium follicles prior to oestrus changed little in AB ewes but declined rapidly from 5.8±0.7 to 4.0±0.6 in W females (P<0.05). Differences in medium follicles between strains were not reflected in the number of large (≥5.5mm) or the growing large follicles during the follicular phase. Around oestrus, plasma oestradiol concentrations were higher for W in comparison to AB ewes (22.3±12.6 vs. 11.8±6.2pg/ml; P<0.01) and mean ovulation rates were 1.8±0.8 and 1.1±0.3 for respectively W and AB ewes (P<0.01). In conclusion, the increased ovulation rate in the W strain is related to an extended period of follicle recruitment with appearance of co-dominance effects.

Reproductive response of fat‐tailed Barbarine ewes subjected to short‐term nutritional treatments including spineless cactus (Opuntia ficus‐indica f. inermis) cladodes

Reproductive outputs in fat-tailed Barbarine sheep in central Tunisia are often low because of feed shortage and the low nutritive value of diets. Supplementation with conventional concentrates is economically unsuitable in central Tunisia, so more cost-effective and sustainable alternative feeding strategies need to be developed. We tested effects of short-term nutritional treatments including cactus cladodes during the induction of 'male effect' on fertility and prolificacy parameters (follicular growth, ovulatory response and early embryo losses). One hundred and twenty ewes were distributed in 4 equal groups balanced for live weight grazed natural pastures and were supplemented for 21days, starting day 10 after introduction of rams, with cactus cladodes (CA), cactus cladodes and soybean meal (CAS), concentrate (CC) or only soybean meal (S). Nutritional treatment did not affect live weight in this experiment. Ewes receiving cactus had higher number of large pre-ovulatory follicles (≥6mm; 1.08±0.05), between days 14 and 19 after introduction of rams, than females in the CC and S ewes (0.64±0.06; p<0.05). However, there were no differences in the onset of oestrous behaviour in response to 'male effect' or in the number of corpora lutea. Average ovulation rates were 1.42±0.16 for CC, 1.47±0.13 for CAS, 1.31±0.15 for CA and 1.31±0.13 for S groups respectively. Finally, reproductive wastages at day 35 after mating were not different between groups being 0.33±0.19 for CC, 0.60±0.17 for CAS, 0.43±0.16 for CA and 0.31±0.15 for S groups respectively. It is concluded that Barbarine ewes fed nutritional treatments including cactus performed similarly to those receiving diets including conventional concentrate feeds.

Assessment of mating management effect on genealogical parameters highlighting the genetic variability in a not closed fat-tailed Barbarine sheep pedigree

Abstract. The Barbarine sheep is generally managed within small interconnected herds. The goal of the present work is to investigate the effect of the mating management on genetic variability in a registered flock which starts showing a productivity falling, especially in lamb’s survival and this despite a practice of outbreeding. Pedigree data of 11136 animals born between 1977 and 2007 were used to compute genealogical parameters. A first investigation of the lambs-parents relationships highlighted two periods that we denoted: P1 and P2. During P1, the mating strategy had been progressively based on animals born within the flock, whereas during P2, ewes and rams coming from outside the herd were gradually introduced as parents with unknown genealogy. This change in matings policy has been emphasised by plotting equivalent complete generations averaged whether by year of birth or maximum number of traced generations. All the computed genealogical parameters have been affected by the matings policy change and especially the individual average relatedness and realised effective size, which seem to be powerful tools to monitor the genetic variability within a population that is not closed to exchanges. An important effect of pedigree depth has been detected; this would require special attention to the matings of individuals with deepest genealogy. In spite of this effect, the heterozygote deficiency within the herd confirmed that the genetic variability has not been much affected along the flock life, which confirms that the decline in productivity should not be allotted to matings’ policy, but probably to other management factors.

Infestation of tracer lambs by Fasciola hepatica in Tunisia: determining periods for strategic anthelmintic treatments

Ovine fasciolosis causes high morbidity and mortality rates, resulting in large economic losses to the sheep industry in northern Tunisia. The authors surveyed ovine fasciolosis (Fasciola hepatica infestation) in a Barbarine sheep flock in the humid region of Tunisia (Sejnane, Governorate of Bizerte) over two consecutive years, 2004 to 2005. To assess the dynamics of fluke infestation, a total of 36 tracer lambs were introduced into the flock successively, in groups of three, every two months, and their infestations were monitored by coproscopy and necropsy. Coproscopic analysis revealed high mean percentages of infestation of 60% and 65% for flock lambs and ewes, respectively. Similarly, a high percentage of infestations was recorded in the tracer lambs (more than 70%) post mortem. Significant fluctuations in infestation dynamics were observed in the tracer lambs, and three distinct infestation periods were identified: a period of very low, non-constant infestation risk during the warm period (from July to October); a high-risk period from March to June, and a third period with a variable but constant infestation risk (from November to February). Based on these results, the authors propose strategic flukicide treatments with triclabendazole, aimed at reducing mollusc infestation and subsequent pasture contamination by metacercariae, during two main periods: in September and in February, just before the reactivation of the molluscs from aestivation and hibernation, respectively.

Merits of the fat-tailed Barbarine sheep raised in different production systems in Tunisia: digestive, productive and reproductive characteristics

Barbarine sheep is the dominant breed in Tunisia. This fat-tailed breed present in all production systems is characterised by metabolic and digestive adaptation to the contrasting environment conditions prevailing in the country (heat stress, water deprivation, salinity etc.). The fat tail (1.5 to 7kg) is an energy reservoir that is used in periods of feed scarcity. Moreover, the rumen of this breed harbours a microflora enabling it to valorize low-quality roughages and native range vegetation. Barbarine sheep could make benefit from a wide range of local feed resources like fodder shrubs (e.g. cactus and oldman saltbushes), tannin-containing shrubs (e.g. Acacia cyanophylla) and agro-industrial by-products (e.g. olive cake, bran etc. conserved in the form of feed blocks or pellets). It has a very shallow anoestrous, the intensity of which is dependant upon nutrition conditions rather than day length as temperate breeds. Productive and reproductive performances of late pregnant-early suckling, pre-mating ewes and also rams of this breed are not affected when some alternative feed resources replace common feedstuffs which are expensive and cannot afford regularly to smallholders. In brief, the merits of the Barbarine sheep in the production systems and other main adaptive mechanisms of this breed are discussed in this paper. The prospective of Barbarine sheep husbandry in the system dynamics, climate change and the evolution of the socioeconomic context are also envisaged.

Differences in preovulatory follicle dynamics and timing of preovulatory LH surge affect fertility of maiden sheep reared in semi-arid extensive conditions

In the current study follicular dynamics, pituitary function, ovulatory response and luteal activity of 30 maiden Barbarine sheep were analyzed according to oestrus occurrence and lambing outcome after oestrus synchronisation with cloprostenol. Animals were retrospectively classified in three groups named as O− ( n = 7, ewes not displaying oestrus), O+L− ( n = 7, ewes showing oestrus but failing to lamb) and O+L+ ( n = 16; ewes showing oestrus and lambing thereafter). All the sheep ovulated and daily transrectal ultrasonographies revealed that preovulatory follicles were present at cloprostenol injection in all the animals. In sheep O+L+ and O+L−, 50% and 57% of the ovulatory follicles were the largest follicles at cloprostenol treatment (mean size of 4.1 ± 0.26 mm and 4.3 ± 0.74 mm, respectively). In O− ewes, the same percentage was higher (86%, P < 0.05 when compared to group O+L+; mean size of 4.0 ± 0.46 mm). The number of large follicles and the final diameter of the ovulatory follicles at oestrous tended thereafter to be higher in group O+L+ (1.4 ± 0.1 and 6.4 ± 0.2) than in groups O+L− (1 ± 0.2 and 5.7 ± 0.36) and O− (0.9 ± 0.2 and 5.9 ± 0.5, respectively). Conversely, the number of medium follicles at oestrus detection was higher in the group O+L− (2.1 ± 0.3, P < 0.05) than in the other two groups (1 ± 0.2 and 1 ± 0.3 for O+L+ and O− respectively). Timing of preovulatory LH surge was earlier for ewes O− (24.0 ± 4.75, P < 0.05) than for sheep O+L+ and O+L− (37.9 ± 2.45 h and 38.0 ± 4.75 h, respectively) and 94% of O+L+ ewes had a LH surge between 16 h and 64 h after cloprostenol injection compared to 57% in O+L− and O− groups ( P < 0.05). Thus, maiden Barbarine sheep failing to display oestrus or conceive showed alterations in their follicular dynamics and, thereafter, pituitary function and ovulatory response.

Wood ash treatment, a cost-effective way to deactivate tannins in Acacia cyanophylla Lindl. foliage and to improve digestion by Barbarine sheep

Three in vitro experiments and one in vivo experiment were carried out to study the effect of wood ash sources (6 L wood ash solution/kg fresh plant leaves) and levels and treatment duration on the nutritive value of acacia leaves. In Experiment 1, samples of fresh (F), dried (D), or dried and ground (DG) acacia were soaked for 6 h in water or acacia wood ash solution (120 g of wood ash dry matter/L of water). Soaking acacia in water decreased total extractable phenols (TP), total extractable tannins (TT) and extractable condensed tannins (CT). Wood ash treatment led to a further decrease of these phenolic compounds and was highest with DG acacia. Experiment 2 investigated different levels of acacia wood ash (0, 120, 180 and 240 g wood ash dry matter/L of water) and treatment duration (1, 2 and 3 days). The higher the level of wood ash, the lower proportion of TP and CT in acacia was noted. In Experiment 3, two sources of wood ash (i.e., acacia and Aleppo pine) and the same solution of each source of wood ash were used eight times. The two sources of wood ash had similar deactivating effect on TP and CT. The rate of decrease of TP and CT was highest when the same wood ash solution was used four consecutive times and decreased progressively thereafter. In these three experiments, water and wood ash treatment reduced organic matter and crude protein content but substantially increased the neutral detergent fibre (NDFom) content of treated acacia. In the fourth experiment, we treated acacia with acacia wood ash (180 g/L of water for 2 days) and the same solution was used five times. Treated and untreated acacia were air-dried and fed ad libitum to two groups, each of four Barbarine rams together with 300 g of concentrate. Wood ash treatment did not affect intake and OM digestibility of the diet but increased crude protein and NDFom digestibility ( P < 0.05). Feeding untreated acacia resulted in negative N balances but with wood ash treatment, N balance was positive. Microbial N supply was not affected by wood ash treatment. It is concluded that wood ash treatment is a cost-effective way to deactivate tannins in acacia leaves, although additional energy is needed to ensure utilisation of the available N.