Ovine Breeds Research Articles

Population structure of eleven Spanish ovine breeds and detection of selective sweeps with BayeScan and hapFLK

The goals of the current work were to analyse the population structure of 11 Spanish ovine breeds and to detect genomic regions that may have been targeted by selection. A total of 141 individuals were genotyped with the Infinium 50 K Ovine SNP BeadChip (Illumina). We combined this dataset with Spanish ovine data previously reported by the International Sheep Genomics Consortium (N = 229). Multidimensional scaling and Admixture analyses revealed that Canaria de Pelo and, to a lesser extent, Roja Mallorquina, Latxa and Churra are clearly differentiated populations, while the remaining seven breeds (Ojalada, Castellana, Gallega, Xisqueta, Ripollesa, Rasa Aragonesa and Segureña) share a similar genetic background. Performance of a genome scan with BayeScan and hapFLK allowed us identifying three genomic regions that are consistently detected with both methods i.e. Oar3 (150–154 Mb), Oar6 (4–49 Mb) and Oar13 (68–74 Mb). Neighbor-joining trees based on polymorphisms mapping to these three selective sweeps did not show a clustering of breeds according to their predominant productive specialization (except the local tree based on Oar13 SNPs). Such cryptic signatures of selection have been also found in the bovine genome, posing a considerable challenge to understand the biological consequences of artificial selection.

RAPD and SCAR markers as potential tools for detection of milk origin in dairy products: Adulterant sheep breeds in Serra da Estrela cheese production

Serra da Estrela Protected Designation of Origin (PDO) cheese is the most famous Portuguese cheese and has a high commercial value. However, the adulteration of production with cheaper/lower-quality milks from non-autochthones ovine breeds compromises the quality of the final product and undervalues the original PDO cheese. A Randomly Amplified Polymorphic DNA (RAPD) method was developed for efficient detection of adulterant breeds in milk mixtures used for fraudulent production of this cheese. Furthermore, Sequence Characterized Amplified Region (SCAR) markers were designed envisioning the detection of milk adulteration in processed dairy foods. The RAPD-SCAR technique is here described, for the first time, to be potentially useful for detection of milk origin in dairy products. In this sense, our findings will play an important role on the valorization of Serra da Estrela cheese, as well as on other high-quality dairy products prone to adulteration, contributing to the further development of the dairy industry.

The Effect of Weight Loss on the Muscle Proteome in the Damara, Dorper and Australian Merino Ovine Breeds.

Seasonal Weight Loss (SWL) is an important constraint, limiting animal production in the Tropics and the Mediterranean. As a result, the study of physiological and biochemical mechanisms by which domestic animal breeds respond to SWL is important to those interested in animal breeding and the improvement thereof. To that end, the study of the proteome has been instrumental in gathering important information on physiological mechanisms, including those underlying SWL. In spite of that, little information is available concerning physiological mechanisms of SWL in production animals. The objective of this study was to determine differential protein expression in the muscle of three different breeds of sheep, the Australian Merino, the Dorper and the Damara, each showing different levels of tolerance to weight loss (low, medium and high, respectively). Per breed, two experimental groups were established, one labeled “Growth” and the other labeled “Restricted.” After forty-two days of dietary treatment, all animals were euthanized. Muscle samples were then taken. Total protein was extracted from the muscle, then quantified and two-dimensional gel electrophoresis were conducted using 24 cm pH 3–10 immobiline dry strips and colloidal coomassie staining. Gels were analyzed using Samespots® software and spots of interest were in-gel digested with trypsin. The isolated proteins were identified using MALDI-TOF/TOF. Results indicated relevant differences between breeds; several proteins are suggested as putative biomarkers of tolerance to weight loss: Desmin, Troponin T, Phosphoglucomutase and the Histidine Triad nucleotide-binding protein 1. This information is of relevance to and of possible use in selection programs aiming towards ruminant animal production in regions prone to droughts and weight loss.

Mitogenome revealed multiple postdomestication genetic mixtures of West African sheep.

Notable diversity observed within African ovine breeds makes them of great interests, but limited studies on genetic origins and domestications remain poorly understood. Here, we investigate the evolutionary status of West African native breeds, Djallonke and Sahelian sheep using mitogenome sequencing. Compared with other ovine mitogenome sequences, West African sheep were revealed a Eurasian origin, and the initially tamed sheep breeds in West Africa have been genetically mixed with each other and mixed with European breeds. Worldwide domestic sheep is deemed the Eurasian origin and migrated west to Europe and Africa and east to the Far East, in which dispersed and received selection for acclimation to autochthonic environment independently and ultimately evolved into different native breeds, respectively. Our results contribute to the comprehensive understanding of the domestic sheep origin and reveal multiple postdomestication genetic amelioration processes.

Fertility of undiluted ram epididymal spermatozoa stored for several days at 4°C

In vitro preservation of the male gamete is a challenge in the development of artificial insemination techniques for domestic animals. Specific strategies and diluents have been developed for the preservation of the fertilizing ability of the semen for each species. However, the epididymal medium has been demonstrated to be the best sperm environment to maintain sperm viability over several days and weeks for mammals. The aims of this study were to evaluate the motility and in vivo fertility of ram epididymal spermatozoa when the semen was stored for up to 4 days at 4°C undiluted in epididymal plasma. The study was undertaken with two ovine breeds (Ile de France and Corriedale). The motility of epididymal spermatozoa was better preserved in the undiluted epididymal fluid than when epididymal spermatozoa were diluted in classic ovine extender such as skim milk. During storage, the decrease in the percentage of motile sperm was lower if the epididymal spermatozoa were collected immediately after epididymal sampling than 24 h after castration or animal death. The fertility obtained after cryopreservation of the stored sperm and subsequent intrauterine insemination ranged from 55% to 24% following 24 to 96-h sperm storage. There was a linear regression relationship between fertility and the number of motile sperm inseminated for both breeds. These results show that it is possible to keep epididymal sperm motile and fertile for several days without dilution. Such a method of sperm preservation could be a final possibility for animals of high genetic value or for endangered species when the collection of semen before death of the animal is not possible.

Variation of biochemical parameters of ovine blood according to genotype and sex after the stalling period.

Abstract. It is considered to be necessary to assess the metabolic status of ovine regarding the modern consumers model, which are increasingly concerned about safe meat production without adverse effects on their health. This leads to an increased preference for meat produced naturally or ecological products. Aims: The objectives of sheep farms are to obtain milk and meat in a sustainable system mainly based on animal health and welfare. Health is a central element to the animals’ welfare as biological functioning of the body is influenced by natural environmental conditions. Predominant factor for the occurrence of metabolic disturbances in sheep is reduced dietary diversity. Based on these considerations, our research objectives were to highlight the health and welfare of sheep naturally bred by determining the influence of various factors on the metabolic profile. Materials and methods: Blood samples were collected from sheep of different breeds and age groups (26 males and 26 females of Karakul breed and 26 males and 26 females of Tzurcana breed) after the stalling period. Biochemical parameters were determined using the Accent 200 automatic biochemical analyzer. Results: Biochemical profile indicators determined on blood samples from studied Karakul and Tzurcana ovine breeds, following statistical analysis, showed insignificant differences between males and females for each separate breed, for: total protein concentration, albumin, cholesterol, triglycerides, glucose, amylase, alkaline phosphatase, calcium and aspartate aminotransferase (Tzurcana breed) and magnesium for the two breeds. The reduced level of serum proteins in the spring season was a consequence of a feed deficiency in leguminous hay, which contributed to the decrease of the total serum protein level. Obtained results from our experiments showed calcium concentration as established within the limits mentioned in the specialized literature, as a consequence of the use in spring of alfalfa hay feed, which is a rich source of vitamins and mineral substances, especially calcium. Conclusion: Current research showed that biochemical profile values in studied lamb and adult ovine populations were influenced by the cold season and specific feeding during stalling time, but these variations represent animal organism adaptation to environmental conditions, ensuring dynamical balance.

CONTRIBUTION TO THE GENETIC DETERMINISM OF THE SHEEP’S MILK QUALITY. RACE INFLUENCE (HAMRA AND OULED DJELLAL) ON PHYSICO-CHEMICAL PARAMETERS AND PROTEIN PROFILE

In order to study the race effect on the physico-ch emical characteristics and protein profile, two she ep or ovine breeds Hamra and Ouled Djellal were raised in the same condition sat the ITELV (National institu te of breeding) (Ain Hajar-Saida, Algeria). The analys es were focused on the pH, density, freezing, fat, total protein, dry defatted extract and total dry extract . The results obtained or these parameters showed n o significant differences between the two races. Then the protein fractions were isolated and analyzed b y Poly Acryl Amide Gel Electrophoresis (PAGE) under different conditions (native and in presence of urea). Th e resulting electrophoretic profiles have identified similarities between the two breeds milk.

Does the Fat Tailed Damara Ovine Breed Have a Distinct Lipid Metabolism Leading to a High Concentration of Branched Chain Fatty Acids in Tissues?

Fat tailed sheep breeds are known for their adaptation to nutritional stress, among other harsh production conditions. Damara sheep, native to Southern Africa, have recently been exported to other areas of the world, particularly Australia, aiming to produce lamb in semi-arid regions. Damaras have a unique hanging fat tail, a fat depot able to be mobilized under nutritional stress. In this article we perform an in-depth characterization of the fatty acid profiles of the fat tail in underfed and control Damara rams. Profiles were very similar between experimental groups, with the exception of palmitic acid (16:0) that was lower (P = 0.014) in underfed animals. However, the most striking result was the very high proportions of non-terminal branched chain fatty acids found in the fat tail adipose tissue, as well as the gastrocnemius muscle of Damara rams. The muscle of Dorper and Merino rams used in the same experiment did not present non-terminal branched chain fatty acids, suggesting that Damara rams have a unique lipid metabolism. Herein, we interpret this trait relating it to a higher ability of Damara sheep to digest fibrous fodder and to putative differences in the propionate metabolism by comparison to other sheep breeds.

Classification of four ovine breeds of southern peninsular zone of India: Morphometric study using classical discriminant function analysis

Six morphometric traits (height at withers, body length, chest girth, ear length, tail length and body weight) were analyzed to characterize from a breed point of view 1981 sheep from four ovine breeds (Bellary, Kenguri, Hassan and Mandya) of southern peninsular zone of India. Discriminant Function Analysis was used to distinguish between four breeds by morphometric traits. The population variability showed Kenguri ewes were the largest and heaviest followed by Bellary, Hassan and Mandya whereas Kenguri rams were followed by Bellary, Mandya and Hassan. Overall sexual dimorphism (m/f) was 1.13, with Kenguri males being 47% heavier than females. The coefficient of variation of all traits in four breeds ranged from 4.06% to 30.28%. The flocks and age effects showed a high heterogeneity among females of different flocks. Height at withers was most discriminating trait in separating the four sheep breeds. The Mahalanobis distance of the morphological traits between Kenguri and Mandya sheep was most while the least differentiation was observed between Kenguri and Bellary sheep. Nearest neighbour discriminant analysis showed that most Kenguri sheep were classified into their source population followed by Mandya. However, varied percentages of misclassification between different breeds were observed showing the level of genetic exchange that has taken place between the breeds overtime. UPGMA based dendrogram showed formation of two separate groups; Mandya and Hassan clustered together while Bellary and Kenguri formed other group.

Evaluation of two Iranian domestic ovine breeds for their pathological findings to gastrointestinal infection of Haemonchus contortus.

The generally warm, moist environmental conditions in the Northwestern Iran are ideal for survival and growth of the egg and larval stages of Haemonchus contortus and other gastrointestinal nematodes (GIN) of sheep and goats.A total of 2,421 animals were slaughtered and examined from July 2010 to July 2011 in Urmia abattoir. In case of sheep, 225 out of 2,421 were positive and prevalence of H. contortus infestation was 9.3%. Sex wise prevalence of H. contortus in sheep was 33.08% (76/229) in male and 66.22% (149/225) in female. The females indicated significantly (P<0.05) higher prevalence (66.22%) as compared to males (33.08%). The highest prevalence was recorded in the spring (April) and the lowest was in summer (July), respectively. On microscopic examination, infiltration of mononuclear cells and eosinophils in gastric glands, periglandular hyperemia and hemorrhage, mucous gland hyperplasia, connective tissue proliferation and necrosis was observed. Also, in mixed abomasal infection with Haemonchus and Ostertagia species, mucosal hyperplasia and increased mucous glands and sometimes cystic glands were seen. Statistical analysis using SPSS software, and Chi-square test, demonstrated a non-significant difference between ages and abomasal PH values of infected and healthy sheep (P<0.05). But the difference between sexes, seasons and abomasal lesions was significant (P>0.05).

Characterization of the Mayo-Kebbi Sheep: a Previously Unrecognised Ovine Breed of the Agro-Pastoral Zone of South-West Chad

The characterisation is main activitie in order to identify important trait of ruminants. Information of phenotypic and morpho-biometric characteristics of the Mayo-Kebbi sheep is not available yet. The aim of the study is to describe the qualitative and morpho-biometric characteristics of Mayo-Kebbi sheep. The location of the study was South-West of Chad. A total of 1511 sheep from 50 sites and 350 farms were inventoried. The samples were taken as many as possible based on the field conditions to observe pattern of colour, other visible traits and morphobiometric data. The results indicate that the Mayo-Kebbi sheep is closer to the Arab, the bicolour or white Peul ovine rather than to the local Djallonke breed called kirdimi” in Chad. The dominant distinctive visible traits are the straight to hooked chamfer (90.3%), the tail length (hock level, 62.1%), the close-cropped hair (70.1%), the short hair (70.9%) and the white dress with spots on the head (65.0%) or more specifically ocular spots (25.3%), also referred to as black glasses. The averages wither height, body length, chest depth and ear length were 75.25±3.72, 65.25±4.11, 30.00±4.05 and 15.50±1.95 cm by males respectively. Wither height, tail length and chamfer length were affected by sex (p0.05). The zoo-economic parameters include prolificacy and better than average fertility. High frequency of twining and average daily gains for both sexes of 87.5 g between days 8 and weaning (4 months) are worth mentioning. The characteristics reported here suggest that this sheep represented rather a distinct breed than a local variety or race, of an already recognized breed.

CARACTERÍSTICAS FÍSICO-QUÍMICAS E CITOLÓGICAS DO LÍQUOR DE OVINOS SADIOS DA RAÇA SANTA INÊS

The occurrence of neurological disease is widespread in clinical medicine of domestic animal, but there are few studies documenting the normal composition of cerebrospinal fluid (CSF) in ovine, especially Santa Ines breed. This study establishes the parameters for normal physiochemical and cytological analysis of cerebrospinal fluid as an aid for diagnosis of neurological disorders in this breed. For this, 40 adult ovine animals, aged between six and 18 months, were used for puncture of lumbosacral CSF. The aspect and color shower a clear and colorless pattern. The average density was 1.006 ± 0.0064, protein concentration was 25.27 ± 6.64 mg/dL and glucose concentration was 46.89 ± 10.99 mg/dL. Enzymes had concentration averages of 116.72 ± 80.79 U/L for creatine kinase; 17.43 ± 11.91 U/L for lactate dehydrogenase and 17.08 ± 3.85 U/L for aspartate aminotransferase. The results for the global cell count were 4.61 ± 4.96 leukocytes/µL (0 to 15 lymphocytes, 0 to 10 monocytes, 1 to 14 neutrophils). Considering the lack of reference data for the physiochemical and cytological CSF analysis of Santa Ines ovine breed, it is recommended that the results obtained in this study are considered normal values for the breed.KEYWORDS: biochemistry; CFS; cytology; small ruminant; standard features.

Study of Wool Characteristics in the Aranese Ovine Breed

SUMMARY: To date, no ethnological study on the wool characteristics of the Spanish Aranese ovine breed has been published.Fifty three animals belonging to this breed are tested as fleece samples. Each sample is analyzed for fleece type and length, yield byisoalcohol scouring, fiber length for each kind of fiber, variation in fiber diameter, and proportions of non-medullated and me dullated orkemp fibers. Fiber length appears shorter than that previously reported for the breed by other authors. Fleeces of the Aranese sheep breedcan be described as square, simple, semi-open and short with a relatively high yield by isoalcohol scouring and low medullati on levels,thus indicating good potential quality and greater suitability for potential processing than other similar meat breeds. KEY WORDS: Fiber diameter; Fleece; Kemp; Medullation; Sheep; Yield. INTRODUCTION The Aranese sheep breed is one of the three local sheepbreeds that exist in Catalonia (NE Spain). The other two sheepbreeds common in the country are Ripollesa and Xisqueta(Esteban, 2003). Although all of these breeds are used mainlyfor meat production as wool is sold as a by-product at a verylow price, even so, wool data from the Aranese must be seenas an important contribution to the breed ethnologicalcharacterization which is precisely the purpose of this study.The native region of the breed is the Aran Valley.The Aran Valley is a small region (620.47 km

Genetic Variation and Relationship of Six Indian Sheep Breeds Adapted to the Northwestern Arid Zone of Rajasthan

This study illustrates the genetic diversity and relationships within and among six Indian sheep breeds of the northwestern arid region of Rajasthan, based on microsatellite markers. The range of allele diversity was 7.72-9.56, and gene diversity was 0.686-0.766, revealing that these breeds possessed substantial amounts of genetic diversity. Positive F (IS) values suggested a deficit of heterozygotes in all six breeds. Despite the declining status of the Marwari, Chokla, Jaisalmeri, Magra and Pugal breeds, an absence of a recent genetic bottleneck was evident from the data. The genetic differentiation estimate (F (ST)=6.1%) suggested low levels of differentiation between the breeds. Genetic distance estimates revealed a close relationship between the Magra-Pugal and Nali-Jaisalmeri breed pairs. This information forms a framework for designing genetic management and conservation programs for these valuable ovine breeds.

Technical note: A simplified PCR-based assay for the characterization of two prolactin variants that affect milk traits in sheep breeds

In the present study, a rapid and cost-effective PCR-based assay was developed for the genetic identification of 2 different variants within intron 2 of the prolactin gene. This polymorphism has previously been associated with milk traits in some ovine breeds and was recently proposed as a potential marker for future breeding schemes in dairy sheep. Until now, 2 alleles (A and B) have been identified by PCR-RFLP that included HaeIII digestion of a 2.5-kb PCR fragment. By partial sequencing of the prolactin gene intron 2, it was found that the B variant results from a 23-bp deletion of the A variant of the prolactin gene and not from an extra HaeIII digestion site, as had been reported. This finding assisted the design of new primers for analysis of prolactin intron 2 variants based on the size of an easily amplified short PCR product, thereby avoiding the need and cost for additional digestions. The method was validated by genotyping 80 animals from 2 breeds and showed 100% sensitivity and specificity compared with the PCR-RFLP assay. The established simplified PCR assay was then successfully used to genotype 356 Chios sheep.

Dietary properties of lamb meat and human health

The quality of meat obtained by Fabrianese heavy lambs (33 kg) reared in the Italian Sibillini mountains national park under extensive conditions had been investigated. Twenty entire male lambs had been used in this experiment; the Longissimus Thoracis et Lumborum muscle, taken from all the 20 animals, was analyzed for chemical composition, fatty acid, cholesterol and mineral contents. Protein content was 22.1%, fat content 4.5%, cholesterol 63.5 mg/100 g. The most represented fatty acid was oleic acid (37.62% of total fatty acids), followed by palmitic acid (26.31% of total fatty acids). Phosphorus and potassium were the two most represented minerals in muscles examined, respectively 285.6 and 329.5 mg/100 g. The results of this study demonstrated the good quality of the meat obtained by a local ovine breed slaughtered at higher final body weight when compared with the most common suckling lambs normally commercialized in Italy.

Searching for genes of interest in Sheep

SUMMARY In the past, several studies have been performed to look for genes affecting traits of interest using microsatellite markers in sheep. Even if numerous chromosomal regions have been detected, few genes and causal mutations have been identified. The recent availability of high density SNP chip in sheep is a technological revolution for genomic researches and breeding selection. Firstly, genomic research in small ruminants will be boosted towards the identification of causative mutations underlying large genetic effects on sustainability traits, or the identification of very closely linked genetic markers that allow selecting genes in ovine breeding programmes. Secondly, such new molecular tools allow considering a new type of selection: the genomic selection. The principle of this selection is to use marker effects (without any information about the underlying genes) estimated within a part of the population which is phenotyped and genotyped (called the training population) and applying these effects to the rest of the genotyped population. However, the genomic selection might not always be a profitable strategy in sheep.

Characterization and Genetic Study of the Ovine α S2 -Casein (CSN1S2) Allele B

An interesting and quite complex protein pattern has been described at ovine milk proteins but the genetic control of the variation observed was assessed only in few cases. The aim of this work was to characterize the ovine alpha ( s2 )-casein (CSN1S2) B variant, first observed in the Italian Gentile di Puglia, a fine-wooled ovine breed, and to investigate its occurrence in two further breeds, the Sarda and Camosciata, which are the most widespread dairy breeds in Italy. The B variant differs from the most common form A with two amino acid exchanges: Asp(75) --> Tyr(75) and Ile(105) --> Val(105). The first substitution, resulting in a loss of a negative charge, is responsible for the higher isoelectric point of the B protein variant, which allows its detection by isoelectric focusing electrophoresis (IEF). The occurrence of CSN1S2*B in Sarda and Comisana was demonstrated. Since the Asp(75) --> Tyr(75) substitution modifies the protein electric charge, milk properties may result affected to some extent.

A Genome Wide Survey of SNP Variation Reveals the Genetic Structure of Sheep Breeds

The genetic structure of sheep reflects their domestication and subsequent formation into discrete breeds. Understanding genetic structure is essential for achieving genetic improvement through genome-wide association studies, genomic selection and the dissection of quantitative traits. After identifying the first genome-wide set of SNP for sheep, we report on levels of genetic variability both within and between a diverse sample of ovine populations. Then, using cluster analysis and the partitioning of genetic variation, we demonstrate sheep are characterised by weak phylogeographic structure, overlapping genetic similarity and generally low differentiation which is consistent with their short evolutionary history. The degree of population substructure was, however, sufficient to cluster individuals based on geographic origin and known breed history. Specifically, African and Asian populations clustered separately from breeds of European origin sampled from Australia, New Zealand, Europe and North America. Furthermore, we demonstrate the presence of stratification within some, but not all, ovine breeds. The results emphasize that careful documentation of genetic structure will be an essential prerequisite when mapping the genetic basis of complex traits. Furthermore, the identification of a subset of SNP able to assign individuals into broad groupings demonstrates even a small panel of markers may be suitable for applications such as traceability.

The study of the ovaries' state in local Bulgarian ewe's breeds by real-time ultrasonography

The aim of this study was the characterization of the ovaries' state in local Bulgarian ovine breeds at the moment of ovulation by real-time transrectal ultrasonography. It was observed 32 ewes of Bulgarian local breeds Karakachanska and West-Oldmountainous between 1,5 and 4 years old, housed under closely to their natural conditions. Ovaries were examined ultrasonically after estrus synchronization with the implantation of intravaginal sponges containing 45 mg of Cronolone over 14 days. The effect of age and breed on the variability of the ovary's size and preovulatory follicle's size was studied.