Algeria represents a reservoir of genetic diversity with local sheep breeds adapted to a large range of environments and showing specific features necessary to deal with harsh conditions. This remarkable diversity results from the traditional management of dryland by pastoralists over centuries. Most of these breeds are poorly productive, and the economic pressure leads farmers to realize anarchic cross-breeding (that is, not carried out in the framework of selection plans) with the hope to increase animal's conformation. In this study, eight of the nine local Algerian sheep breeds (D'men, Hamra, Ouled-Djellal, Rembi, Sidaoun, Tazegzawt, Berber and Barbarine) were investigated for the first time by genome-wide single-nucleotide polymorphism genotyping. At an international scale, Algerian sheep occupied an original position shaped by relations with African and European (particularly Italian) breeds. The strong genetic proximity with Caribbean and Brazilian breeds confirmed that the genetic make-up of these American breeds was largely influenced by the Atlantic slave trade. At a national scale, an alarming genetic dilution of the Berber (a primitive breed) and the Rembi was observed, as a consequence of uncontrolled mating practices with Ouled-Djellal. A similar, though less pronounced, phenomenon was also detected for the Barbarine, another ancestral breed. Genetic originality appeared to be better preserved in Tazegzawt, Hamra, D'men and Sidaoun. These breeds should be given high priority in the establishment of conservation plans to halt their progressive loss. For Berber and Barbarine that also occur in the bordering neighbor countries, urgent concerted transnational actions are needed.
Scrapie is a prion disease that affects the sheep and goats. It belongs to the group of transmissible spongiform encephalopathies (TSE). TSEs are characterized by the accumulation of the pathological form (PrP) of the cellular prion protein (PrP). The susceptibility of sheep to scrapie is influenced by polymorphisms in the gene (PRNP). The aim of this study was to identify the genetic variability of sheep in Algerian sheep. Two-hundred and thirteen Algerian sheep from eight breeds (Ouled Djellal, Rembi, Hamra, Berbere, Barbarine, Sidaou, Taadmit and Tazegzawt) with no clinical manifestation of scrapie were analysed. Sequencing of the entire coding sequence of PRNP showed four main alleles (ARQ, ARR, AHQ and ARH) based on codons 136, 154 and 171 with different frequencies among the investigated breeds. Moreover, 14 additional nonsynonymous polymorphisms (Q101R, N103K, M112T, A116P, M137I, L141F, I142M, H143R, N146S, R151G, Y172D, N176K, H180Y and S240P) as well as two synonymous polymorphisms at codons 231 and 237 were found in the gene. Interestingly, the N103K, M137I and I142M polymorphisms were not described in sheep. The ARQ, ARR and ARH haplotypes were present in all breeds with a highest frequency of ARQ in Barbarine. The ARH was absent in Barbarine breed and the VRQ haplotype was absent in all Algerian breeds studied. The ARQ and ARR alleles were the most common with frequencies ranging from 30 to 65% and from 8 to 26%, respectively, in different breeds. These results represent the first study on variability in Algerian sheep and may serve as a basis for the development of breeding programmes to render national sheep breeds resistant to scrapie.
Aim:The aim of the present study was to define the onset of puberty in Tazegzawt ram lambs, an Algerian sheep breed in endangered status with a small population in its local area.Materials and Methods:Body growth (body weight and thoracic perimeter), scrotal circumference (SC), penis development stages, and seminal parameters (volume, concentration, and motility) were measured. Data were recorded at fortnightly intervals in 10 animals from 9 to 49 weeks of age.Results:On the basis of seminal analyses, puberty occurred between 29 and 45 weeks of age. At 29 weeks of age, 30% of lambs reached puberty, and at 45 weeks of age, puberty was observed in 100% of the analyzed animals. Body weight appeared as the most determinant factor, and the onset of puberty was observed when animals reached 43.2±6.4 kg body weight with 25.8±3.7 cm of SC. Seminal analyses revealed that all parameters increased regularly from puberty onset except for sperm concentration. The mean semen volume during the study period was 0.48±0.33 mL with 0.84±0.6 mL at 37 weeks of age. Sperm concentration evolved similarly as semen volume; at 29 and 43 weeks of age, the sperm concentration was 942×106 and 1904×106 spermatozoa/mL, respectively. Kinematic parameters including the percentage of motility, the percentage of progressive motility, and gametes velocities as determined by Computer-Aided Sperm Analyzer showed the highest values at 49 weeks of age.Conclusion:The current results revealed that, in Tazegzawt ram lambs, puberty occurs between 29 and 45 weeks when animals reach 43.2±4.6 kg body weight.
The richness of the variability of the sheep genetic resources is untapped. We have noted the presence of 12 sheep breeds in Algeria such as Ouled Djellal, Rembi, Hamra, Berber, Barbarine, D'man, Sidaou, Tadmit, Tazegzawt, Ifilene, Srandi and Daraa, which are well adapted to the conditions of the environments. Unfortunately, anarchic crossings lead to dispersion and an erosion of the genetic capital of the breeds, the increase of consanguinity in the herds and a decrease of the returns of the farms. The medium-term risk is the absorption of certain «breeds" by others, and the loss of certain characters that make the specificity of our breeds. In addition, the documentation on the diversity of sheep breeds in Algeria is minimal or absent, so several breeds require a phenotypic and zootechnical description to know their performance. This document describes the sheep genetic resources present in Algeria and the diversity between them based on surveys that have been carried out for more than 17 years, in 40 wilayas, based on the phenotypic characterization of these "breeds" in their cradles, in order to make an updated breed distribution map and a new breed classification.
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