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National animal gene banks have acquired substantial quantities of germplasm that protect and preserve a wide range of livestock breeds. New challenges and growth opportunities are emerging. A key challenge will be increased gene bank use, but this requires increased characterization of phenotypes and genotypes for populations and collections.
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Bancos de Espécimes Biológicos , Desenvolvimento Psicológico , Animais , Gado/genética , Genótipo , FenótipoRESUMO
Egyptian Baladi cattle is one of the few native taurine breeds which remain in the original domestication area of Bos taurus, the Nile Valley (Upper Egypt). Apart from its evolutive relevance, the breed is well-adapted and integrated into the traditional family farming systems, with great potentialities for local sustainable rural development. The diversity and structure of the Baladi population were assessed using 28 genetic microsatellite markers. Within and between-breeds diversity, its relations with other cattle breeds, and an inference on its origin and evolution, were analyzed. Results reported high levels of diversity, with an average number of alleles (Na) of 11.39, observed heterozygosity (Ho) of 0.68, and expected heterozygosity (He) of 0.75. The studied population was in Hardy-Weinberg disequilibrium, which could be ascribed to its internal structure. The comparison between breeds using factorial correspondence analysis, Reynolds genetic distance evaluation, and genetic structure analysis suggested slight influences of Bos indicus. Upper Egypt's rural communities have preserved the Baladi cattle breed, protecting this historical and biological heritage against the constant and indiscriminate introduction of exotic genetic resources along the history of development of the breed. Developing and implementing conservation and breeding programs is crucial for the preservation and improvement of the breed.HIGHLIGHTSBaladi cattle breed is a well-defined and highly diverse breed.Higher diversity levels are found in northern and central governorates.A clear geographical cluster is formed around the Nile Delta.Baladi cattle may be reminiscent of the ancient 'pharaoh' cattle.Assiut's population acted as the most ancestral population nucleus.
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Variação Genética , Repetições de Microssatélites , Bovinos/genética , Animais , Variação Genética/genética , Heterozigoto , Marcadores Genéticos , Repetições de Microssatélites/genética , AlelosRESUMO
This is the first comprehensive study to reveal genetic variation and population structure at genome level in six Anatolian (Anatolian Black, East Anatolian Red, South Anatolian Red, South Anatolian Yellow, Turkish Grey Steppe, and Zavot) and two cosmopolitan (Brown Swiss and Holstein Friesian) cattle breeds reared in Türkiye. Being 20 samples from each population, a total of 160 blood samples retrieved from representative herds were utilized to generate genomic libraries by ddRADseq method. Genomic libraries sequenced by Illumina HiSeq X Ten instrument revealed a total of 211,119 bi-allelic SNPs with high call rate. Compared to cosmopolitan cattle breeds, a higher genetic variation was observed in native Turkish cattle with an average of 0.380 observed heterozygosity. Genetic distances were comparatively low between native cattle breeds, whereas the highest genetic distance (0.064) was detected between South Anatolian Yellow and Brown Swiss. Population structure analyses showed that the native Turkish and cosmopolitan cattle breeds were clearly different from each other according to their phylogenetic origin. Besides, a high level of genetic admixture was detected among Anatolian Black, Turkish Grey Steppe, South Anatolian Red, and South Anatolian Yellow, whereas East Anatolian Red and Zavot were distinct from the other native and cosmopolitan cattle breeds. TreeMix algorithm under the assumption of one and two migration events revealed a migration route from Anatolian clade to Anatolian Black, while a second migration edge was drawn from Brown Swiss to East Anatolian Red. This study demonstrates the importance of national conservation studies in the native breeds whose population size has dramatically decreased. In addition, SNP arrays and next-generation sequencing platforms are recommended for future studies to reveal the genetic variation of other local Turkish livestock species to arrange effective conservation programs.
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Variação Genética , Polimorfismo de Nucleotídeo Único , Animais , Bovinos/genética , Filogenia , Turquia , Polimorfismo de Nucleotídeo Único/genética , Heterozigoto , Alelos , Variação Genética/genética , GenótipoRESUMO
Following the recent domestication process of the European rabbit (Oryctolagus cuniculus), many different breeds and lines, distinguished primarily by exterior traits such as coat colour, fur structure and body size and shape, have been constituted. In this study, we genotyped, with a high-density single-nucleotide polymorphism panel, a total of 645 rabbits from 10 fancy breeds (Belgian Hare, Champagne d'Argent, Checkered Giant, Coloured Dwarf, Dwarf Lop, Ermine, Giant Grey, Giant White, Rex and Rhinelander) and three meat breeds (Italian White, Italian Spotted and Italian Silver). ADMIXTURE analysis indicated that breeds with similar phenotypic traits (e.g. coat colour and body size) shared common ancestries. Signatures of selection using two haplotype-based approaches (iHS and XP-EHH), combined with the results obtained with other methods previously reported that we applied to the same breeds, we identified a total of 5079 independent genomic regions with some signatures of selection, covering about 1777 Mb of the rabbit genome. These regions consistently encompassed many genes involved in pigmentation processes (ASIP, EDNRA, EDNRB, KIT, KITLG, MITF, OCA2, TYR and TYRP1), coat structure (LIPH) and body size, including two major genes (LCORL and HMGA2) among many others. This study revealed novel genomic regions under signatures of selection and further demonstrated that population structures and signatures of selection, left into the genome of these rabbit breeds, may contribute to understanding the genetic events that led to their constitution and the complex genetic mechanisms determining the broad phenotypic variability present in these untapped rabbit genetic resources.
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Dissecting genetic variation of local breeds is important for the success of conservation. In this research, we investigated the genomic variation of Colombian Creole (CR) pigs, with a focus on the breed-specific variants in the exonic region of 34 genes with reported effects on adaptive and economic traits. Seven individuals of each of the three CR breeds (CM, Casco de Mula; SP, San Pedreño; and ZU, Zungo) were whole-genome sequenced along with 7 Iberian (IB) pigs and 7 pigs of each of the four most used cosmopolitan (CP) breeds (Duroc, Landrace × Large White, and Pietrain). Molecular variability in CR (6,451,218 variants; from 3,919,242, in SP, to 4,648,069, in CM) was comparable to that in CP, but higher than in IB. For the investigated genes, SP pigs displayed less exonic variants (178) than ZU (254), CM (263), IB (200), and the individual CP genetic types (201 to 335). Sequence variation in these genes confirmed the resemblance of CR to IB and indicates that CR pigs, particularly ZU and CM, are not exempt from selective introgression of other breeds. A total of 50 exonic variants were identified as being potentially specific to CR, including a high-impact deletion in the intron between exons 15 and 16 of the leptin receptor gene, which was only found in CM and ZU. The identification of breed-specific variants in genes related to adaptive and economical traits can bolster the understanding of the role of gene-environment interactions on local adaptation and points the way for effective breeding and conservation of CR pigs.
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Aclimatação , Genoma , Suínos , Animais , Colômbia , Fenótipo , GenômicaRESUMO
Animal genetic resources in the world are rich and varied. Local species have strong adaptability to the local environment. They are precious resources, and need to be protected by the whole world. In this paper, we summarize the current situation of conservation activities of livestock and poultry resources abroad, including the relevant policies and measures, financial support, genetic material conservation, research projects, and the benefits of conservation animal genetic resources. The actions of conservation of animal genetic resources reflects the increasing recognition of the importance of biodiversity by people around the world. The variety of conservation activities of genetic materials in the world and its benefits reflect that the concept of biodiversity has already been accepted by public and the government. Conservation of animal genetic resources is the primary action for the revitalization of Chinese seed industry. This paper has enlightenment significance for strengthening the conservation of animal genetic resources in China.
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Conservação dos Recursos Naturais , Gado , Animais , China , Biodiversidade , Aves Domésticas/genéticaRESUMO
In southern Africa, the Nguni cattle breed is classified as an indigenous and transboundary animal genetic resource (AnGR) that manifests unique adaptation abilities across distinct agroecological zones. The genetic integrity of various ecotypes is under potential threat due to both indiscriminate crossbreeding and uncontrolled inbreeding. The aim of this study was to assess the genetic diversity and autozygosity that exist both across countries (ES: eSwatini; SA: South Africa) and within countries (SA), between purebred stud animals (SA-S) and research herds (SA-R). Subsets of 96 ES, 96 SA-S, and 96 SA-R genotyped for 40,930 common SNPs were used to study genome-wide profiles of runs of homozygosity (ROH) and heterozygosity (ROHet) as well as inbreeding levels and population structure. The highest percentage (39.8%) of the 2168 ROH segments was 4-8 Mbp in length, whereas 65% of the 935 ROHet segments fell within the 0.5-1 Mbp length category. Inbreeding coefficients indicated positive but low inbreeding (FROH>1Mbp range: 0.025 for SA-S to 0.029 for SA-R). Principal component (PCA) and population structure analyses illustrated genome-level distinctness of (1) the Nguni from global indicine (Boran) and taurine (Hereford) breeds (K = 3), (2) the SA Nguni populations from the ES Nguni population (K = 4), and (3) different Nguni ecotypes within countries (K = 8). Furthermore, greater admixture was observed for the SA-R population compared to purebred SA-S population (shared ancestry = 0.631 ± 0.353 compared to 0.741 ± 0.123), and fewer genomics-defined ES ecotypes were observed than phenotypically (pre)defined. Overall, the results illustrated that genetic uniqueness within the sampled Nguni cattle resulted from both geographic isolation and exposure to different breeding strategies (and, selection pressures). A further loss of genetic variability should be monitored to prevent the endangerment of unique and beneficial ecotypes.
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Genoma , Endogamia , Bovinos/genética , Animais , África do Sul , Essuatíni , Genômica/métodos , Genótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Brazilian hair sheep constitute a genetic diversity hotspot. These animals are found in the harsh environments of the Brazilian Northwest (semi-arid) region. Genotypes (50K SNP chip) from seven Brazilian sheep breeds (five hair and two coarse wool types) and 87 worldwide breeds were used to test for population structure, admixture and genetic diversity. Moreover, phylogenetic trees evaluating migration events between genetic groups were built. Brazilian Somali, a fat-tailed breed, had a close relationship with East African breeds and clustered distinctly from other Brazilian breeds. Brazilian Blackbelly and Barbados Blackbelly had a close relationship. The Morada Nova breed did not show close relationships with European or African breeds, revealing a single migration event from an Algerian hair breed. Brazilian Fat-tail and Morada Nova share a common ancestor, but the former showed introgressions from Brazilian Somali and Afrikaner breeds, explaining the fat-tail phenotype. The Santa Inês breed received a substantial contribution from Brazilian Bergamasca and showed an admixed origin with recent introgressions from other breeds, mainly from Suffolk. Furthermore, Brazilian Somali and Brazilian Fat-tail are the most endangered sheep genetic resources in Brazil and should be the focus for ex situ conservation programs. In conclusion, Brazilian hair sheep show an African origin and are characterized by diverse genetic composition, reinforcing the need for conservation of these genetic resources, and at the same time, this highly diverse group has variability that can be used in breeding programs.
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Pelo Animal , Cruzamento , Genoma , Genótipo , Carneiro Doméstico/genética , Pelo Animal/fisiologia , Animais , Brasil , FilogeniaRESUMO
To establish the diversity, structure, and phylogenetic relationships among Colombian Creole cattle, six native breeds and one introduced breed were genotyped for 20 microsatellite loci. The average number of alleles per breed ranged from 7050 (Romosinuano) to 10,100 (Casanareño), and the expected heterozygosity ranged from 0.691 (San martinero) to 0.785 (Casanareño). The deviation from the Hardy-Weinberg equilibrium (HWE) was statistically significant (p < 0.05) in 59 out of 120 tests carried out in the six breeds for the 20 microsatellite loci analyzed. Colombian Creole bovine breeds have maintained a high level of genetic differentiation within the same populations (93%), and the rest is explained by differences between breeds (7%). The differentiation pattern and the genetic relationships between the Colombian Creole bovine breeds showed high consistency with the evolutionary history of each. Both the Bayesian grouping analysis and the neighbor-joining tree exhibited a reliable grouping pattern, which revealed two main groups: one comprised by the breeds Blanco Orejinegro, Hartón del Valle, Costeño Con Cuernos, Romosinuano, and San Martinero, and the other one by the Creole breed Casanareño and Zebu. These were probably caused by different historical, reproductive, and geographic isolation precedents, as well as by different levels of inbreeding. This study will help understand the genetic characteristics of Colombian Creole cattle and will benefit future conservation programs.
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Bovinos/genética , Variação Genética , Genética Populacional , Repetições de Microssatélites , Animais , Teorema de Bayes , Colômbia , FilogeniaRESUMO
There are few animal germplasm/gene bank collections in Brazil, and basic studies are needed to attend the future internal and external demands from international partners. The aim of this work was to validate a "proof of concept" that integrates spatial (georeferenced data) and genetic data regarding the local of origin from 3518 DNA samples from 17 different genetic groups or breeds of sheep in the Brazilian Germplasm bank. Spatialisation shows that not all genetic groups have samples in the bank, and collection is concentrated in the conservation nuclei spread nationwide. Only 21% of states with a specific breed have samples in the gene bank. The mean number of animals sampled per collection was 32, while the mean distance travelled to collect samples was 262 km from the conservation nuclei. For example, the Brazilian Somali were only collected in the conservation nucleus in Ceará State. No samples were collected to date for the Cariri breed, which is recognised by the Brazilian Ministry of Agriculture. Only two farms and one breed in the bank are from the northern region. Of the 27 states, there are samples in the gene bank of sheep from 13, so several states have no samples, requiring collection from herds outside the official system of conservation to make sure that studies using this germplasm realised are not biased. Significant genetic differences are seen above 332 km, which should guide future sampling efforts. Suggestions are given for improving the quantity, quality and diversity of samples in the gene bank.
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Biodiversidade , Cruzamento , Variação Genética , Ovinos/genética , Agricultura , Animais , Bancos de Espécimes Biológicos , Brasil , Conservação dos Recursos NaturaisRESUMO
The Chino Santandereano (CHS) creole cattle breed has undergone an adaptation process of more than 500 years to the Colombian mountainous tropics. Despite its advantages, the breed has been replaced by specialized cattle that put it at risk of extinction. The aim of this work was to estimate the genomic diversity and population structure of the nucleus of conservation of the CHS breed. Thirty-seven CHS and 20 Brahman animals were genotyped due to the possible introgression of genes with the GGP Bovine LD v3 chip. Quality control was performed, and linkage disequilibrium (LD), effective population size (Ne), ROH segments, homozygosity, and genomic inbreeding in the breed were estimated. Subsequently, 50 K genomic information of the Holstein (n = 30) and Romosinuano (n = 8) breeds were included to estimate the minor allele frequency (MAF) with common markers and constructing the graphs of the principal component analysis (PCA). Pairwise FSTs were estimated and a neighbor-joining tree was constructed using the IBS matrix. Admixture was used with k = 2 to 10 for the racial composition. LD (r2) was found up to a distance of 0.13 Mb, r2 > 0.3 at a distance of 340.3 kb, and Ne of 32 ± 1. ROH inbreeding was 5.36 ± 0.86%, with a higher contribution from recent inbreeding (4.55%). The PCA showed that the creole breeds were closer together, and the Brahman was more distant. The admixture analysis suggested k = 5 possible ancestral groups and shows that within the CHS breed, there seem to be two different groups with little Holstein and Brahman introgression. The genetic diversity parameters obtained in this work show minimal diversity in this breed and reinforce the need to protect this resource and the conservation banks.
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Genoma , Melhoramento Vegetal , Animais , Bovinos/genética , Genômica , Endogamia , Desequilíbrio de LigaçãoRESUMO
Among the animal species first introduced in Brazil during the country's discovery, horses (Equus caballus) stand out because of their evolutionary history and relationship with humans. Among the Brazilian horse breeds, the Pantaneiro draws attention due to its adaptative traits. Blood samples of 116 Pantaneiro horses were divided into six populations based on their sampling location, aiming to identify the existence of genetic structure and quantify genetic diversity within and between them. Populations were compared to elucidate genetic variability and differentiation better and assess the impact of Pantanal's natural geographic barriers on gene flow between populations. Data from the GGP Equine BeadChip (Geneseek-Neogen, 65.157 SNPs) was used to assess basic diversity parameters, genetic distance (FST), principal component analysis (PCA), and population structure (ADMIXTURE) for the sampled animals. Mantel test was also performed to investigate the correlation between the populations' genetic and geographic distances. Results showed high genetic variability in all populations, with elevated levels of admixture in their structure. High levels of admixture make it challenging to establish a racial pattern and, consequently, populations within the breed, being that only one of the populations differentiated itself from the others. No significant correlations between genetic and geographic distances were observed, indicating that environmental barriers did not hinder gene flow between populations, and neither farmers' selection practices might have change breed genetic composition significantly. Low genetic distance and similar heterozygosity values were observed among populations, suggesting strong genetic proximity and low differentiation. Thereby, the Pantaneiro breed does not exhibit genetic subpopulations and could be considered, for conservation purposes, a single big population in the Panatnal region. This study will support sampling strategies for National genebank.
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Variação Genética , Genética Populacional , Animais , Brasil , Cavalos/genética , Fenótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
The indigenous cattle population of Benin is a diverse mix of taurine and hybrid breeds shaped by diverse ecological and climatic conditions with eight agro-ecological zones (AEZ). Presumably, the taurine breeds face current endangerment due to ongoing indicine introgression following climate change and transboundary transhumance. The aim of the study was to investigate the genetic diversity and population structure of the indigenous breeds Lagune, Somba, Pabli and Borgou considering spatial agro-ecological and socio-economic factors (transhumance) based on 50k SNP and microsatellite data. Among the four sampled breeds, six genetic clusters were identified using model-free (discriminant analysis of principal components) and model-based (TESS and ADMIXTURE) methods separating taurine from hybrid breeds. Results based on an extension with publicly available historic SNP data sets from taurine and indicine West African cattle and additional outgroups provided additional insight into changes of genetic structure in the sampled breeds over time. Both taurine breeds, Somba and Lagune, showed a stable foundation but also spatially limited partial indicine introgression associated with transhumance leading to high genetic diversity. In addition, we found evidence for spatial diversity and changes in genetic structure over time in the Borgou breed in comparison of our samples with the historic samples which could be explained by potential continuous indicine introgression into the Borgou breed in two sample regions. Results for the Pabli breed do not conclusively point to full absorbance by the Borgou in comparison with all available Borgou samples. Further research is needed in this regard.
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Cruzamento , Variação Genética/genética , Genética Populacional , Agricultura , Animais , Benin , Bovinos , Análise Discriminante , EcologiaRESUMO
The Nguni cattle breed has distinct populations that are adapted to the different ecological zones of Southern Africa. This study was carried out to assess genetic diversity and establish the relationships among South African (SA), Mozambican (Landim), and Swazi Nguni cattle populations, using 25 microsatellite markers. Genotypic data were generated from deoxyribonucleic acid (DNA) samples of 90 unrelated individuals of the three cattle populations, collected from government conservations and stud herds. DNA profiles of five local beef breeds were used as the reference populations. Most of the 25 microsatellite markers were highly polymorphic across the studied populations, with an overall polymorphic information content (PIC) mean of 0.676. Genetic diversity within populations was high with expected heterozygosity varying from 0.705 ± 0.024 (Landim) to 0.748 ± 0.021 (SA Nguni) and mean number of alleles being highest in the SA Nguni (7.52 ± 0.42). Average observed heterozygosity (0.597 ± 0.046) compared to the expected heterozygosity (0.719 ± 0.022) was lowest for the Swazi Nguni, which also had a high number of Hardy-Weinberg Equilibrium (HWE) deviated loci (13), confirming the relatively high level of inbreeding (0.158 ± 0.058) in that population. Analysis of molecular variance revealed only 9.61% of the total variation between the populations and 90.39% within populations. A short genetic distance (0.299) was observed between Landim and Swazi Nguni, with the SA Nguni (> 0.500) being the most genetically distant population. The distant relationship between SA Nguni and the other two Nguni cattle populations was further confirmed by a principal coordinates analysis. The three Nguni populations clustered independently from each other, despite some evidence of admixture. Therefore, it can be concluded that SA Nguni, Landim, and Swazi Nguni populations in Southern Africa exhibit high levels of genetic diversity and are genetically distant; with the two latter populations being less genetically apart. These results present useful information for the development of strategies for regional management of animal genetic resources, through conservation and sustainable utilisation.
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Bovinos/genética , Variação Genética , África Austral , Alelos , Animais , Cruzamento/métodos , Bovinos/classificação , DNA/química , DNA/isolamento & purificação , Genética Populacional , Genótipo , Cabelo/química , Heterozigoto , Endogamia , Repetições de Microssatélites , Análise de Componente PrincipalRESUMO
Local breeds are recognized as an important element for the maintenance of various and specific farming systems. Challenges for local breeds' management, in a context of crossbreeding with exotic highly productive breeds, have been mainly studied in tropical countries. However, similar situation and challenges are likely to exist in Mediterranean countries subjected to climatic and feed scarcity issues. The objective of this work is to identify the challenges for local breed management in a regional context of informal crossbreeding with highly productive breeds. For this purpose, the case of dairy sheep farming in the region of Thessaly, in Central Greece, was examined. Semi-structured interviews were performed in 46 farms and processed through hierarchical classification on principal components. A follow-up on seven farms raising the Karagouniko sheep breed, the main local breed of the region, was carried on during one milk campaign. Results showed that a diversity of breeding strategies involving local purebred and crossbred flocks coexist in the region. The Karagouniko breed is facing several challenges. The supply in exotic breeding males and their crosses could be wide-scaled and involved a diversity of operators, whereas the supply in breeding males of Karagouniko breed was restrained to between-farm supply among flocks under milk recording scheme. In addition, the heterogeneity of access and quality of collective rangelands affected the farming of Karagouniko breed ewes, whose purebred flocks were significantly associated with the grazing on native grasslands. Finally, unfavorable dairies' policies led Karagouniko farmers to seek higher flock milk production through levers that could impact the vulnerability of the farm, such as earlier lambing period or earlier weaning age. Farmers also questioned the use of highly productive breeds as a potential lever to reach higher flock milk production.
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Cruzamento/métodos , Indústria de Laticínios/métodos , Carneiro Doméstico , Animais , Feminino , Grécia , MasculinoRESUMO
The economic evaluation of farm animal genetic resources plays a key role in developing conservation programs. However, to date, the link between diversity as assessed by neutral genetic markers and the functional diversity is not yet understood. Two genome-wide comparisons, using over 44,000 Single Nucleotide Polymorphisms, identified the markers with the highest difference in allele frequency between the Alpago endangered breed and two clusters, composed of four specialized dairy sheep, and four meat breeds respectively. The genes in proximity of these markers were mapped to known pathways of the Gene Ontology to determine which ones were most represented. Our results indicated that the differences of the Alpago breed from the more productive sheep rely upon genes involved in cellular defense and repair mechanisms. A higher number of different markers and genes were detected in the comparison with the specialized dairy sheep. These genes play a role in complex biological processes: metabolic, homeostatic, neurological system, and macromolecular organization; such processes may possibly explain the evolution of gene function as a result of selection to improve milk yield.
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Mapeamento Cromossômico , Espécies em Perigo de Extinção , Estudos de Associação Genética , Variação Genética/genética , Genoma/genética , Ovinos/genética , Animais , Cruzamento , Marcadores Genéticos/genética , Genótipo , Polimorfismo de Nucleotídeo Único/genética , Especificidade da EspécieRESUMO
Local breeds of livestock are of conservation significance as components of global biodiversity and as reservoirs of genetic variation relevant to the future sustainability of agriculture. One such rare historic breed, the Chillingham cattle of northern England, has a 350-year history of isolation and inbreeding yet shows no diminution of viability or fertility. The Chillingham cattle have not been subjected to selective breeding. It has been suggested previously that the herd has minimal genetic variation. In this study, high-density SNP genotyping with the 777K SNP chip showed that 9.1% of loci on the chip are polymorphic in the herd, compared with 62-90% seen in commercial cattle breeds. Instead of being homogeneously distributed along the genome, these loci are clustered at specific chromosomal locations. A high proportion of the Chillingham individuals examined were heterozygous at many of these polymorphic loci, suggesting that some loci are under balancing selection. Some of these frequently heterozygous loci have been implicated as sites of recessive lethal mutations in cattle. Linkage disequilibrium equal or close to 100% was found to span up to 1350 kb, and LD was above r(2) = 0.25 up to more than 5000 kb. This strong LD is consistent with the lack of polymorphic loci in the herd. The heterozygous regions in the Chillingham cattle may be the locations of genes relevant to fitness or survival, which may help elucidate the biology of local adaptation in traditional breeds and facilitate selection for such traits in commercial cattle.
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Bovinos/genética , Heterozigoto , Endogamia , Polimorfismo de Nucleotídeo Único , Animais , Conservação dos Recursos Naturais , Inglaterra , Feminino , Loci Gênicos , Genótipo , Técnicas de Genotipagem , MasculinoRESUMO
The objective of this study was to characterize the declining Somba cattle population in its production system context. Two-hundred-twenty-four (224) cattle farm-households were surveyed in the Boukombe district, the natural habitat of the breed in North-West Benin. Information on their socioeconomic characteristics and on their herd management practices were recorded using a semi-structured questionnaire. In addition, 15 body measurements were recorded from 102 adult cattle. Three types of breeders were distinguished: the owners-herders (54.0 %); the absentee owners (40.2 %) and the professional herders (5.8 %). The average cattle herd sizes were 4.7 ± 3.70 and 58.6 ± 22.83 heads for owner-managed and entrusted herds, respectively. Offtakes were more associated with sociocultural purposes (75.5 %) than market. While crop farming was the main occupation and income source of their owners, the Somba cattle were used for ploughing during the rainy season. In contrast to the widely accepted belief that this indigenous genetic resource is mainly threatened by crossbreeding and/or replacement, our findings suggest high mortalities due to diseases, feed and water shortages and poor reproduction management as the main causes of the decline of this cattle population. Somba cattle generally have short horns and a small body size. However, bulls have significantly (P ≤ 0.05) longer horns (21.2 ± 16.44 cm against 13.9 ± 7.21 cm), higher height at withers (99.7 ± 6.97 cm against 95.9 ± 5.76 cm) and body length (149.7 ± 12.87 cm against 146.8 ± 11.01 cm) than cows. All surveyed farmers expressed their willingness and readiness to participate in and contribute materially or financially to any program towards a sustainable use and preservation of this breed which they perceived as hardy and embedded in their culture. We therefore argue that strategies for its sustainable use and conservation should consist of simultaneously improving general herd management practices, organizing farmers and involving them in participatory breed improvement programs.
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Criação de Animais Domésticos/economia , Doenças dos Bovinos/epidemiologia , Bovinos/fisiologia , Agricultura , Animais , Benin , Cruzamento , Características da Família , Feminino , Humanos , Hibridização Genética , Masculino , Estações do Ano , Inquéritos e Questionários , Clima TropicalRESUMO
One problem in modern dogs is a high occurrence of physical diseases, defects and disorders. Many breeds exhibit physical problems that affect individual dogs throughout life. A potential cause of these problems is inbreeding that is known to reduce the viability of individuals. We investigated the possible correlation between recent inbreeding and health problems in dogs and used studbook data from 26 breeds provided by the Swedish Kennel Club for this purpose. The pedigrees date back to the mid-20th century and comprise 5-10 generations and 1 000-50 000 individuals per pedigree over our study period of 1980-2010. We compared levels of inbreeding and loss of genetic variation measured in relation to the number of founding animals during this period in the investigated dog breeds that we classified as 'healthy' (11 breeds) or 'unhealthy' (15) based on statistics on the extent of veterinary care obtained from Sweden's four largest insurance companies for pets. We found extensive loss of genetic variation and moderate levels of recent inbreeding in all breeds examined, but no strong indication of a difference in these parameters between healthy versus unhealthy breeds over this period. Thus, recent breeding history with respect to rate of inbreeding does not appear to be a main cause of poor health in the investigated dog breeds in Sweden. We identified both strengths and weaknesses of the dog pedigree data important to consider in future work of monitoring and conserving genetic diversity of dog breeds.
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Cães/genética , Variação Genética , Saúde , Endogamia/estatística & dados numéricos , Alelos , Animais , Feminino , Efeito Fundador , Masculino , Linhagem , SuéciaRESUMO
Developing country livestock production systems are diverse and dynamic, and include those where existing indigenous breeds are currently optimal and likely to remain so, those where non-indigenous breed types are already in common use, and systems that are changing, such as by intensification, where the introduction of new breed types represents significant opportunities. These include opportunities to improve the livelihood of the world's poor, increase food and nutrition security and enhance environmental sustainability. At present, very little research has focused on this issue, such that significant knowledge gaps in relation to breed-change interventions remain. The purpose of this study is to raise awareness of this issue and suggests strategic research areas to begin filling these knowledge gaps. Such strategic research would include (i) assessing the impact of differing breed types in developing country livestock productions systems, from a range of viewpoints including intrahousehold livelihood benefit, food and nutrition security at different scales, and environmental sustainability; (ii) identification of specific livestock production systems within developing countries, and the type of livestock keepers within these system, that are most likely to benefit from new breed types; and (iii) identification of new breed types as candidates for in-situ testing within these systems, such as through the use of spatial analysis to identify similar production environments combined with community acceptance studies. Results of these studies would primarily assist stakeholders in agriculture, including both policy makers and livestock keepers, to make informed decisions on the potential use of new breed types.