Moroccan Breeds Of Sheep Research Articles

Genomic Uniqueness of Local Sheep Breeds From Morocco.

Sheep farming is a major source of meat in Morocco and plays a key role in the country’s agriculture. This study aims at characterizing the whole-genome diversity and demographic history of the main Moroccan sheep breeds, as well as to identify selection signatures within and between breeds. Whole genome data from 87 individuals representing the five predominant local breeds were used to estimate their level of neutral genetic diversity and to infer the variation of their effective population size over time. In addition, we used two methods to detect selection signatures: either for detecting selective sweeps within each breed separately or by detecting differentially selected regions by contrasting different breeds. We identified hundreds of genomic regions putatively under selection, which related to several biological terms involved in local adaptation or the expression of zootechnical performances such as Growth, UV protection, Cell maturation or Feeding behavior. The results of this study revealed selection signatures in genes that have an important role in traits of interest and increased our understanding of how genetic diversity is distributed in these local breeds. Thus, Moroccan local sheep breeds exhibit both a high genetic diversity and a large set of adaptive variations, and therefore, represent a valuable genetic resource for the conservation of sheep in the context of climate change.

Genetic variability analysis of 26 sheep breeds in the Czech Republic

Genetic variability analysis of 26 sheep breeds in the Czech Republic

The origin of sheep settlement in Western Mediterranean

The arrival of Neolithic culture in North Africa, especially domestic animals has been essentially documented from archaeological records. As the data relative to sheep are scarce, we studied the genetic relationship between Moroccan sheep breeds and Mediterranean ones using the sequencing of 628 bp of the mitochondrial DNA control region in 193 Moroccan individuals, belonging to six breeds, and 652 sequences from other breeds in Europe and Middle East. Through Network analysis and an original phylogenetically derived method, the connection proportions of each Moroccan breed to foreign ones were estimated, highlighting the strong links between Moroccan and Iberian breeds. The first founders of Moroccan sheep population were issued at 79% from Iberia and 21% from a territory between Middle East and Africa. Their calculated expansion times were respectively 7,100 and 8,600 years B.P. This suggests that Neolithization was introduced by a double influence, from Iberia and from another route, maybe Oriental or Sub-Saharan. The consequence of the environmental changes encountered by founders from Iberia was tested using different neutrality tests. There are significant selection signatures at the level of Moroccan and European breeds settled in elevated altitudes, and an erosion of nucleotide diversity in Moroccan breeds living in arid areas.

Genetic homogenization of indigenous sheep breeds in Northwest Africa

Northwest-African sheep represent an ideal case-study for assessing the potential impact of genetic homogenization as a threat to the future of traditional breeds that are adapted to local conditions. We studied ten Algerian and Moroccan breeds of sheep, including three transboundary breeds, distributed over a large part of the Maghreb region, which represents a geographically and historically coherent unit. Our analysis of the dataset that involved carrying out Genome-wide SNP genotyping, revealed a high level of homogenization (ADMIXTURE, NetView, fineSTRUCTURE and IBD segments analyses), in such a way that some breeds from different origins appeared genetically undistinguished: by grouping the eight most admixed populations, we obtained a mean global FST value of 0.0024. The sPCA analysis revealed that the major part of Morocco and the Northern part of Algeria were affected by the phenomenon, including most of the breeds considered. Unsupervised cross-breeding with the popular Ouled-Djellal breed was identified as a proximate cause of this homogenization. The issue of transboundary breeds was investigated, and the Hamra breed in particular was examined via ROH fragments analysis. Genetic diversity was considered in the light of historical archives and anthropological works. All of these elements taken together suggest that homogenization as a factor affecting the Maghrebin sheep stock, has been particularly significant over the last few decades, although this process probably started much earlier. In particular, we have identified the policies set by the French administration during the colonial period of the region’s history as a causal factor that probably contributed significantly to this process. The genetic homogenization that we have observed calls into question the integrity of the farm animal genomic resources represented by these local breeds, whose conservation is of critical importance to the future of the livestock sector.

Estimating population structure and genetic diversity of five Moroccan sheep breeds by microsatellite markers

Investigating the genetic variability and structure of Moroccan sheep breeds will reveal crucial information for the conservation and management of this population. This study used 22 microsatellite markers to assess the genetic diversity among and within five Moroccan sheep breeds: Sardi (N=35), Boujaad (N=31), Timadhite (N=35), Beni Guil (N=35), and D⿿man_Morroco (N=35). In the whole sample, a total of 299 alleles were detected. The five breeds showed a relatively high level of gene diversity ranging between 0.725 (D⿿man_Morocco) and 0.764 (Timahdite). The Analysis of Molecular Variance (AMOVA) indicated that variability among populations contributed only 3.64% of the observed genetic diversity. Wilcoxon tests of excess heterozygosity under the two-phase model (TPM) did not provide strong evidence for recent bottlenecks in the five studied breeds. Unrooted neighbour joining (NJ) tree for the modified Cavalli-Sforza chord distance (DA), pairwise multilocus estimates of an effective number of migrants (Nm) and the Bayesian clustering method cohesively revealed poor structure of genetic variation among breeds. Our results also show that in spite of the high level of phenotypic diversity in the Moroccan sheep breeds, the past breeding strategies could lead to genetic admixture occurring as a result of relatively high gene-flow among the breeds.

Between- and within-breed morphological variability in Moroccan sheep breeds

SummaryThe objective of this study was a morphological characterization of five Moroccan sheep breeds (Béni Guil, Boujaâd, D'man, Sardi and Timahdite) to assess between- and within-breed variability using multivariate analyses. Fourteen morphological measurements were collected on 876 adult animals of both sexes in 98 different flocks located in 22 geographic localities of five breeds. The multiple analysis of variance revealed that significant morphological differences existed between breeds. The overall proportion of total variance due to between-breed component was 28.3 percent. The factor analysis revealed three factors accounting for 50.1, 11.8 and 7.54 percent of total variance. The first factor had high loadings for variables relating to body size, whilst the second factor had high association with traits reflecting tail length and ear size. The third factor had high loadings for wool trait. The squared Mahalanobis distance between the five sheep breeds were highly significant (P< 0.001). The largest morphological divergence was shown between Béni Guil and Sardi breeds (23.5) and the smallest one was between Boujaâd and Sardi breeds (3.54). The discriminant functions clearly discriminated and assigned 94.4 percent of Béni Guil, 79.7 of Boujaâd, 88.5 percent of D'man, 86.7 of Sardi and 80.1 percent of Timahdite sheep into their breed of origin. Overall morphological differences observed within-breeds were due for 18.1 percent to geographic locality and for 20.7 percent to flock management. It was concluded that the information reported in this study will be the basis for the establishment of characterization and selection strategies for Moroccan sheep.

Reproduction and production performance of Moroccan sheep breeds.

Abstract The Moroccan sheep population consists of several breeds. The most important breeds are the D’man, Timahdite, Béni Guil, Sardi, Béni Ahsen and Boujaâd. With regard to reproduction performance, these breeds could be divided into two groups. The D’man breed reaches puberty at an early age, has a long breeding season, a short postpartum anoestrus and a high prolificacy. The other local breeds are not prolific and have a limited breeding season. All the breeds perform similarly in terms of the growth traits. Nevertheless, the Sardi breed has a slightly higher growth rate and good carcass characteristics, while the D’man has a moderate growth rate. Milk yield of local breeds is low, but milk composition is in line with that of other sheep breeds. The milk production is, in general, sufficient to nurse one lamb. Except for the D’man breed that has a low fleece weight, the other breeds have similar and moderate fleece weights. However, wool quality of local sheep is poor.

Diallel cross of three Moroccan breeds of sheep: II. Reproductive performance and productivity of purebred ewes.

A diallel cross involving three Moroccan breeds of sheep (Sardi, Beni Guil, and D'man) was analyzed by least squares procedures. A total of 456 ewes were mated to 22 rams and this resulted in 528 lambs born from 412 ewes. D'man ewes had by far the highest general performance as measured by total weight of lamb weaned, even though the average live weight per lamb was the lowest for the three breeds; this resulted from the higher number of lambs weaned per ewe for the D'man. The least squares means for litter size at birth per ewe lambing were 2.04, 1.01, and 1.11 for D'man, Beni Guil, and Sardi ewes, respectively. The comparable figures for litter size at weaning were 1.55, .90, and .99, respectively, and the least squares means for total weight of lamb weaned were 20.7, 16.9, and 18.2 kg for D'man, Beni Guil, and Sardi ewes, respectively. The comparable figures for total weight of lamb weaned per 100 kg of ewe weight were 71.1, 44.3, and 41.1 kg/100 kg for D'man, Beni Guil, and Sardi ewes. Conversely, D'man rams had the poorest breeding performances of the rams of the three breeds, and Beni Guil rams had the lowest litter mortality. The breed of ram had only small and nonsignificant effects on all measures of fertility and ewe productivity. The least squares means for number born/ewe lambing were 1.36, 1.35, and 1.44, respectively, for D'man, Beni Guil, and Sardi rams; the comparable least squares means for number weaned per ewe lambing were 1.10, 1.18, and 1.16, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Diallel cross of three Moroccan breeds of sheep: I. Lamb growth and carcass traits

A diallel cross involving three Moroccan breeds of sheep (D'man, Beni Guil, and Sardi) was conducted for two successive years at the Gharb Experiment Station in Morocco. Significant effects associated with breed of sire and breed of dam for live and carcass weights are consistent with differences in mature body size of the three breeds involved. Carcasses of lambs by Sardi sires or out of Sardi dams were the heaviest and those by D'man sires or out of D'man dams were the lightest. Lambs by D'man sires reached the prescribed stage of maturity for slaughter at a younger age than did lambs of Beni Guil sires, and lambs out of Beni Guil dams were younger at slaughter than lambs out of Sardi dams. Because of its genetic potential for high growth rate and carcass weight, the Sardi breed could be used in breeding programs to enhance meat production from sheep in Morocco. With the large and desirable maternal effects expressed by the Beni Guil breed on growth traits and carcass weight per 100 d of age, it could also be used in Morocco as a breed of dam.

Development of the population of ovarian follicles during the prepubertal period in D'man and Timahdite sheep

A quantitative histological analysis of the population of growing follicles in the ovary was made in two Moroccan breeds of sheep differing in their natural ovulation rate: the D'man (2.85) and the Timahdite (1.1). The study was performed on prepubertal animals from 2 months before birth to 4 months after birth. The analysis highlights three distinct periods of development. During the first period (from 2. months before, until 15 days after birth) the total number of growing follicles increases. During the second period (from 15 days to 3 months) the number decreases. During the third period (from 3 months to 4 months) the number of follicles stabilizes. The fall in number during the second period results from strong atresia and from a lower number of follicles starting to grow. During the prepubertal period, the D'man is characterized by a greater initiation of follicular growth from the pool of small follicles and by a lower rate of atresia than the Timahdite.

Performance of D'Man and Sardi sheep on accelerated lambing I. Fertility, litter size, postpartum anoestrus and puberty

Data on four lamb crops in 2.5 years from an experimental flock of sheep established to compare prolific (D'Man) and non-prolific (Sardi) Moroccan breeds of sheep and their crosses are presented. Conception rates, litter size, duration of postpartum anoestrus and age at puberty were recorded. Total productivity was consistently higher in the D'Man breed due to generally higher fertility and higher prolificacy. There were large seasonal variations in fertility of Sardi but not of D'Man ewes. Fertility of Sardi ewes was markedly affected by breed of sire used in mating, D'Man rams inducing a higher proportion of ewes to mate than Sardi rams. However, there was only a small effect of the breed of service ram on synchronization of oestrus. The postpartum anoestrus of D'Man ewes was always short (45 to 60 days) while in the Sardi it varied according to season of lambing, suggesting a winter-spring anoestrus. D'Man ewes had good fertility under one year of age and were close to mature litter size at second lambing at two years of age. Sardi ewes reached puberty at a much later age and did not achieve mature levels of reproductive performance before their third lambing. Ten to 11-month-old ewe lambs and 2-year-old F 1 ewes from Sardi dams were equal to D'Man ewes in fertility. The F 1's reached puberty slightly later than D'Man but much earlier than Sardi and were intermediate between D'Man and Sardi purebreds in litter size.

Performance of D'man and Sardi sheep on accelerated lambing II. Ovulation rate and embryo survival

Data on four lamb crops in 2.5 years from an experimental flock of sheep established to compare prolific (D'Man) and nonprolific (Sardi) Moroccan breeds of sheep and their crosses are presented. Ovulation rate was recorded following matings of three of four seasons. Mean ovulation rates for ewes 30 months and over were 1.32 for Sardi and 3.18 for D'Man, with 99.7% 1's and 2's in Sardi ewes, and a range of one to seven, with 38% ≥ 4, in D'Man ewes. Prenatal survival was high in both breeds. Pregnant Sardi ewes with two corpora lutea (CL) had a survival rate of 89%, and D'Man ewes had survival rates of 90, 82, 69 and 58% for those with 2, 3, 4 and 5 to 7 CL, respectively. Repeatability of ovulation rate averaged 0.18 for Sardi and 0.29 for D'Man, with corresponding values for litter size of 0.18 and 0.27. Young F 1 ewes produced by mating D'Man rams to Sardi ewes were intermediate between the two parent breeds in ovulation rate, and had high prenatal survival.

Seasonal sexual activity and post-partum anoestrus in two Moroccan breeds of sheep: Beni-Guil and Sardi

Twenty-four Beni-Guil and twenty-six Sardi ewes were regularly checked for oestrus during 19 consecutive months following lambing using penis-deviated rams and for ovulation by endoscopy or plasma progesterone level. Fifty percent of the Beni-Guil and Sardi ewes had a first ovulation at 41 and 71 days and first oestrus at 85 and 132 days, respectively. The seasonal anoestrus in both breeds occurs from February to May and is characterized essentially by a lack of expression of oestrous behaviour. Compared to other breeds located at higher latitudes, the two breeds studied showed a more rapid resumption of sexual activity following lambing and a seasonal anoestrus of reduced length and intensity.

Oxytocin concentrations in peripheral blood during the oestrous cycle and after ovariectomy in two breeds of sheep with low and high fecundity.

Oxytocin was measured radioimmunologically during the oestrous cycle in six ewes of each of two local Moroccan breeds of sheep. Concentrations in both breeds approached the lower limit of the assay (3 pg/ml) from 2 days before oestrus, throughout heat and ovulation until day 2 of the cycle. Oxytocin concentrations then increased in both breeds, the resulting highest levels on days 5-7 were, on average, between 30 and 60 pg/ml in the D'man sheep and 13-31 pg/ml in the Timhadite breed. Oxytocin levels then decreased to about 7 pg/ml in the D'man and about 4-5 pg/ml in the Timhadite breed on days 14-15. After ovariectomy oxytocin concentrations remained at about the limit of detection for a further 19-20 days in both breeds.