Genetic diversity among Canadienne, Brown Swiss, Holstein, and Jersey cattle of Canada based on 15 bovine microsatellite markers.

The genetic diversity among Canadienne, Brown Swiss, Holstein, and Jersey cattle was estimated from relationships determined by genotyping 20 distantly related animals in each breed for 15 microsatellites located on separate chromosomes. The Canadienne, Holstein, and Jersey cattle had an average of six alleles per loci compared with five alleles for Brown Swiss. Furthermore, a number of potentially breed-specific alleles were identified. The allele size variance among breeds was similar, but varied considerably among loci. All of the loci studied were equally heterozygous, as were Brown Swiss, Canadienne, and Holstein cattle (0.68-0.69) whereas Jersey cattle showed lower heterozygosity (0.59). The within-breed estimates of genetic distance were greater than zero and significant. The genetic distance between Canadienne and Holstein (0.156), Brown Swiss (0.243), and Jersey (0.235) was negligible, suggesting close relationship. Concurrently, Brown Swiss and Holstein (0.211) cattle also demonstrated close relationship. In contrast, the Jersey breed was genetically distant from the Brown Swiss and Holstein cattle (0.427 and 0.320, respectively). The characterization of Canadienne cattle, as part of the genetic resource conservation effort currently underway in Canada, underscores the difficulty in scientifically establishing unique breeds. Therefore, the need to consider all relevant morphological characteristics and production performance in combination with available cultural, historical, pedigree, and molecular information becomes relevant when identifying breeds for conservation.     

Breed relationships and definition in British cattle: a genetic analysis

The genetic diversity of eight British cattle breeds was quantified in this study. In all, 30 microsatellites from the FAO panel of markers were used to characterise the DNA samples from nearly 400 individuals. A variety of methods were applied to analyse the data in order to look at diversity within and between breeds. The relationships between breeds were not highly resolved and breed clusters were not associated with geographical distribution. Analyses also defined the cohesiveness or definition of the various breeds, with Highland, Guernsey and Jersey as the best defined and most distinctive of the breeds.     

Microsatellite analysis of genetic population structure of zebu cattle (Bos indicus) breeds from north-western region of India

The present study aims to understand the existing genetic diversity and structure of six native cattle breeds (Rathi, Tharparkar, Nagori, Mewati, Gir, and Kankrej) adapted to the north-western arid and semi-arid region of India based on microsatellite loci. Various diversity estimates, mean number of alleles (12.84); effective number of alleles (5.02); gene diversity (0.769), and observed heterozygosity (0.667) reflected the existence of substantial within-breed diversity in all the investigated cattle breeds. Mean estimates of F-statistics: F(IT) = 0.144 ± 0.023, F(IS) = 0.071 ± 0.021, and F(ST) = 0.078 ± 0.014 were significantly different from zero (P < 0.05). The interbreed relationships indicated moderate level of breed differentiation between the six cattle breeds with least differentiation between Kankrej-Mewati pair. The phylogeny structuring further supported close grouping of Kankrej and Mewati breeds. Correspondence analysis plotted Rathi, Tharparkar, and Gir individuals into three separate areas of multivariate space; whereas, Kankrej, Mewati, and Nagori cattle showed low breed specific clustering. This reflected the existence of discrete genetic structure for Tharparkar, Rathi, and Gir, the prominent dairy breeds of the region; whereas, admixture was observed for Kankrej, Mewati, and Nagori individuals.     

Characterization of the genetic diversity, structure and admixture of British chicken breeds

The characterization of livestock genetic diversity can inform breed conservation initiatives. The genetic diversity and genetic structure were assessed in 685 individual genotypes sampled from 24 British chicken breeds. A total of 239 alleles were found across 30 microsatellite loci with a mean number of 7.97 alleles per locus. The breeds were highly differentiated, with an average F(ST) of 0.25, similar to that of European chicken breeds. The genetic diversity in British chicken breeds was comparable to that found in European chicken breeds, with an average number of alleles per locus of 3.59, ranging from 2.00 in Spanish to 4.40 in Maran, and an average expected heterozygosity of 0.49, ranging from 0.20 in Spanish to 0.62 in Araucana. However, the majority of breeds were not in Hardy-Weinberg Equilibrium, as indicated by heterozygote deficiency in the majority of breeds (average F(IS) of 0.20), with an average observed heterozygote frequency of 0.39, ranging from 0.15 in Spanish to 0.49 in Cochin. Individual-based clustering analyses revealed that most individuals clustered to breed origin. However, genetic subdivisions occurred in several breeds, and this was predominantly associated with flock supplier and occasionally by morphological type. The deficit of heterozygotes was likely owing to a Wahlund effect caused by sampling from different flocks, implying structure within breeds. It is proposed that gene flow amongst flocks within breeds should be enhanced to maintain the current levels of genetic diversity. Additionally, certain breeds had low levels of both genetic diversity and uniqueness. Consideration is required for the conservation and preservation of these potentially vulnerable breeds.     

Genetic diversity and population structure of 20 North European cattle breeds

Blood samples were collected from 743 animals from 15 indigenous, 2 old imported, and 3 commercial North European cattle breeds. The samples were analyzed for 11 erythrocyte antigen systems, 8 proteins, and 10 microsatellites, and used to assess inter- and intrabreed genetic variation and genetic population structures. The microsatellites BoLA-DRBP1 and CSSM66 were nonneutral markers according to the Ewens-Watterson test, suggesting some kind of selection imposed on these loci. North European cattle breeds displayed generally similar levels of multilocus heterozygosity and allelic diversity. However, allelic diversity has been reduced in several breeds, which was explained by limited effective population sizes over the course of man-directed breed development and demographic bottlenecks of indigenous breeds. A tree showing genetic relationships between breeds was constructed from a matrix of random drift-based genetic distance estimates. The breeds were classified on the basis of the tree topology into four major breed groups, defined as Northern indigenous breeds, Southern breeds, Ayrshire and Friesian breeds, and Jersey. Grouping of Nordic breeds was supported by documented breed history and geographical divisions of native breeding regions of indigenous cattle. Divergence estimates between Icelandic cattle and indigenous breeds suggested a separation time of more than 1,000 years between Icelandic cattle and Norwegian native breeds, a finding consistent with historical evidence.     

Analysis of genetic relationships between 10 cattle breeds with 17 microsatellites

To guide genetic conservation programmes with objective criteria, general genetic variability has to be taken into account. This study was conducted to determine the genetic variation between 10 cattle breeds by using 17 microsatellite loci and 13 biochemical markers (11 blood groups, the transferrin and β-casein loci). Microsatellite loci were amplified in 31–50 unrelated individuals from 10 cattle breeds: Charolais, Limousin, Breton Black Pied, Parthenais, Montbéliard, Vosgien, Maine-Anjou, Normande, Jersey and Holstein. Neighbor-joining trees were calculated from genetic distance estimates. The robustness of tree topology was obtained by bootstrap resampling of loci. A total of 210 alleles of the 17 microsatellites were detected in this study and average heterozygosities ranged from 0·53 in the Jersey breed to 0·66 in the Parthenais breed. In general, low bootstrap values were obtained: with the 17 microsatellites, the highest bootstrap values concerned the Holstein/Maine-Anjou grouping with an occurrence of 74%; with the biochemical markers, this node had an occurrence of 79% and the Charolais/Limousin grouping appeared with an occurrence of 74%; when microsatellites and biochemical polymorphism were analysed together, the occurrence of the Holstein/Maine-Anjou grouping was 90% and that of the Charolais/Limousin grouping was 42%. These results suggest that 30 microsatellites, a number currently considered as sufficient to distinguish closely related breeds is, in fact, probably insufficient.     

Characterization of experimental cattle populations from Argentina with a low-density SNP genotyping panel

The objectives of the present experiment were to evaluate a low-density SNP array designed for the molecular characterisation of gene banks and to assess the genetic diversity and population structure of beef cattle herds from an Argentinean research station. Forty-nine animals from three breeds (Angus, Hereford, and Argentinean Creole) were genotyped using the multi-species IMAGE001 60-K SNP array (10 K for cattle). Genotypes of other 19 cattle populations from Argentina, other American countries, and Europe were included in the study. Of special interest was the characterization of the Argentinean Creole, the only autochthonous cattle breed in the country. Due to the merging of different datasets, approximately 5 K SNPs were effectively used. Genetic differentiation (F_ST), principal component analysis, neighbour-joining tree of Reynolds distances and ancestry analysis showed that autochthonous American breeds are clearly differentiated, but all have genetic influences of Iberian cattle. The analysed herds of Argentinean Creole showed no evidence of recent admixture and represent a unique genetic pool within local American breeds. An experimental herd and the local commercial Hereford population have also diverged, probably due to the influence of current selection objectives in the breed. Our results illustrate the utility of using low-cost, low density SNP arrays in the evaluation of animal genetic resources. This type of panels could become a very useful resource in developing countries, where most endangered cattle breeds are located. The results also reinforce the importance of experimental herds as reservoir of genetic diversity, particularly in the case of local breeds under-represented in traditional production systems.     

Microsatellite analysis reveals high genetic diversity but low genetic structure in Ethiopian indigenous cattle populations

Ethiopian cattle are under threat from uncontrolled mating practices and are at high risk of becoming genetically homogeneous. Therefore, to evaluate genetic diversity, population structure and degree of admixture, 30 microsatellite markers were genotyped using 351 DNA samples from 10 Ethiopian cattle populations and the Holstein breed. The mean number of alleles per cattle population ranged from 6.93 ± 2.12 in Sheko to 7.50 ± 2.35 in Adwa. The mean observed and expected heterozygosities were 0.674 ± 0.015 and 0.726 ± 0.019 respectively. Ethiopian cattle populations have maintained a high level of within-population genetic differentiation (98.7%), the remainder being accounted for by differentiation among populations (1.3%). A highly significant deficiency in heterozygotes was detected within populations ( F _IS = 0.071; P  <   0.001) and total inbreeding ( F _IT = 0.083; P  <   0.001). The study populations were highly admixed but distinct from pure Bos taurus and Bos indicus breeds. The various levels of admixture and high genetic diversity make Ethiopian cattle populations suitable for future genetic improvement and utilization under a wide range of agro-ecologies in Ethiopia.     

Indigenous domestic breeds as reservoirs of genetic diversity: the Argentinean Creole cattle

Contrary to highly selected commercial breeds, indigenous domestic breeds are composed of semi-wild or feral populations subjected to reduced levels of artificial selection. As a consequence, many of these breeds have become locally adapted to a wide range of environments, showing high levels of phenotypic variability and increased fitness under natural conditions. Genetic analyses of three loci associated with milk production (alpha(S1)-casein, kappa-casein and prolactin) and the locus BoLA-DRB3 of the major histocompatibility complex indicated that the Argentinean Creole cattle (ACC), an indigenous breed from South America, maintains high levels of genetic diversity and population structure. In contrast to the commercial Holstein breed, the ACC showed considerable variation in heterozygosity (H(e)) and allelic diversity (A) across populations. As expected, bi-allelic markers showed extensive variation in He whereas the highly polymorphic BoLA-DRB3 showed substantial variation in A, with individual populations having 39-74% of the total number of alleles characterized for the breed. An analysis of molecular variance (AMOVA) of nine populations throughout the distribution range of the ACC revealed that 91.9-94.7% of the total observed variance was explained by differences within populations whereas 5.3-8.1% was the result of differences among populations. In addition, the ACC breed consistently showed higher levels of genetic differentiation among populations than Holstein. Results from this study emphasize the importance of population genetic structure within domestic breeds as an essential component of genetic diversity and suggest that indigenous breeds may be considered important reservoirs of genetic diversity for commercial domestic species.     

Estimation of breed contributions to present and future genetic diversity of 44 North Eurasian cattle breeds using core set diversity measures

Extinction of breeds threatens genetic diversity of livestock species. The need to conserve genetic diversity is widely accepted but involves in general two questions: (i) is the expected loss of diversity in a set of breeds within a defined future time horizon large enough to establish a conservation plan, and if so (ii) which breeds should be prioritised for such a conservation plan? The present study uses a marker assisted methodology to address these questions. The methodology combines core set diversity measures with a stochastic method for the estimation of expected future diversity and breed marginal diversities. The latter is defined as the change in the total diversity of all breeds caused by a one unit decrease in extinction probability of a particular breed. The stochastic method was validated by means of simulations. A large field data set consisting of 44 North Eurasian cattle breeds was analysed using simplified determined extinction probabilities. The results show that the expected loss of diversity in this set within the next 20 to 50 years is between 1 and 3% of the actual diversity, provided that the extinction probabilities which were used are approximately valid. If this loss is to be reduced, it is sufficient to include those three to five breeds with the highest marginal diversity in a conservation scheme.     

Microsatellite DNA typing for assessment of genetic variability in Tharparkar breed of Indian zebu (Bos indicus) cattle, a major breed of Rajasthan

The present study estimates genetic variability with a set of 25 microsatellite markers in a random sample of 50 animals of Tharparkar breed of Indian zebu (Bos indicus) cattle. Tharparkar is a dual-purpose breed, valued for its milk as well as draught utility, and is adapted to the inhospitable Thar desert conditions of Rajasthan typified by summer temperature hovering above 50 degrees C, sparse rainfall and vegetation, and scarcity of even drinking water. The observed number of alleles ranged from 4 (ETH3, ILSTS030, INRA5, INRA63 and MM8) to 11 (HEL9 and ILSTS034), with allelic diversity (average number of observed alleles per locus) of 6.20. Observed and expected heterozygosity ranged from 0.25 (INRA63) to 0.77 (ETH10), and from 0.51 (HEL5 and HAUT27) to 0.88 (HEL9) respectively. Wide range of genetic variability supported the utility of these microsatellite loci in measurement of genetic diversity indices in other Indian cattle breeds too. Various average genetic variability measures, namely allele diversity (6.20), observed heterozygosity (0.57), expected heterozygosity (0.67) and mean polymorphism information content (0.60) values showed substantial within-breed genetic variability in this major breed of Rajasthan, despite accumulated inbreeding as reflected by high average inbreeding coefficient (F(IS) = 0.39). The Tharparkar population has not experienced a bottleneck in the recent past.     

Genomic characterization of Pinzgau cattle: genetic conservation and breeding perspectives

A genome-wide scan of Slovak Pinzgau cattle was prepared for the first time in order to estimate their genetic diversity at a more detailed level compared to previously published studies. The aim of this study was to describe the genetic diversity based on the runs of homozygosity (ROH_s), linkage disequilibrium (LD) and effective population size (N_eLD) using genome-wide data. Moreover, Bayesian clustering algorithms and multivariate methods were used to detect the population structure, potential admixture level and relationship between Austrian and Slovak Pinzgau cattle with respect to a large meta-population consisting of 15 European cattle breeds. The proportion of ROH segments ranged from 0.43 to 1.91% in Slovak Pinzgau, depending on the minimum size of an ROH. The genomic inbreeding coefficients were higher than the pedigree ones possibly due to the limited number of available generations in pedigree data. The observed N_eLD was close to the limit value characterizing the endangerment status, based both on genomic and pedigree data. Population structure within analyzed breeds based on the Wright’s F_ST index, Nei’s genetic distances, and unsupervised as well as supervised analysis has been established. Overall, these analyses clearly distinguished populations based on their origin. A detailed analysis of the introgression of each breed into the Pinzgau breeds prepared using a Bayesian approach showed that the contribution of Holstein cattle in Austrian as well as Slovak Pinzgau was larger than contribution of beef breeds. A possible reason is the recent usage of Holstein sires to increase milk production. There are considerable differences between well-defined regions that clearly distinguish Austrian and Slovak Pinzgau, despite their close common history. Generally, the breeding program of Austrian Pinzgau is more focused on meat production than Slovak Pinzgau, which was clearly reflected in the obtained autozygosity islands. Considering the genetic establishment of Slovak Pinzgau population the genetic potential of the breed is insufficiently used. On a long term, more global breeding program including very close populations will be more efficient providing higher genetic progress and diversity. Established methodology how to distinguish genealogically close populations on high-throughput molecular information based of Slovak and Austrian Pinzgau can be proposed as general for analysis of differences in all highly related breeds.     

Characterization of the Russian beef cattle breed gene pools using inter simple sequence repeat DNA analysis (ISSR analysis)

The gene pools of beef cattle breeds bred in Russia were characterized on the basis of inter simple sequence repeat DNA analysis (ISSR analysis). Samples of Aberdeen Angus, Kalmyk, and Kazakh Whitehead breeds from Russia, as well as of Hereford breed, hybrids of Kazakh Whitehead and Hereford breeds, and Kazakh Whitehead breed from the Republic of Kazakhstan, were examined. In the examined breeds, 27 AG-ISSR fragments were identified, 25 of which were polymorphic. The examined breeds were different both in the fragment profiles (the presence/absence of individual ISSR fragments) and in their frequencies. It was demonstrated that the hybrid animals lacked some ISSR fragments that were present with high frequencies in parental forms, suggesting considerable genome rearrangement in the hybrid animals (at the regions of microsatellite localization) in crossings of the individuals from different breeds. The level of genetic diversity in Russian beef breeds was consistent with the values typical of farmed populations (breeds). The genetic diversity parameters assessed by applying Nei’s gene diversity index and the Shannon index varied from 0.0218 to 0.0605 and from 0.0225 to 0.0819, respectively. The highest Shannon index value was detected in the Kalmyk breed (0.0837) and Kazakh Whitehead breed from Russia (0.0819), and the highest level of Nei’s gene diversity index was found in the Kalmyk breed (0.0562) and in both populations of the Kazakh Whitehead breed (0.0509 and 0.0605). The high level of genetic similarity (according to Nei) was revealed between Russian beef cattle breeds and Hereford cattle: 0.839 (for the Kazakh Whitehead breed from Russia) and 0.769 (for the Kalmyk breed).     

On the bovine F blood group system

The F system of three Danish cattle breeds as determined by four specific anti-sera is described. In the Jersey breed three alleles are recognised. In the Danish cattle breeds there was no indication of a null allele. However, the phenotypes observed in zebu cattle by means of four reagents suggest the presence of at least six alleles in the bovine F system. Furthermore, the data show that the factors V₁ and V₂ do not form a linear subtype system in all cattle breeds.     

Genome-wide genetic diversity,population structure and admixture analysis in African and Asian cattle breeds

Knowledge about genetic diversity and population structure is useful for designing effective strategies to improve the production, management and conservation of farm animal genetic resources. Here, we present a comprehensive genome-wide analysis of genetic diversity, population structure and admixture based on 244 animals sampled from 10 cattle populations in Asia and Africa and genotyped for 69 903 autosomal single-nucleotide polymorphisms (SNPs) mainly derived from the indicine breed. Principal component analysis, STRUCTURE and distance analysis from high-density SNP data clearly revealed that the largest genetic difference occurred between the two domestic lineages (taurine and indicine), whereas Ethiopian cattle populations represent a mosaic of the humped zebu and taurine. Estimation of the genetic influence of zebu and taurine revealed that Ethiopian cattle were characterized by considerable levels of introgression from South Asian zebu, whereas Bangladeshi populations shared very low taurine ancestry. The relationships among Ethiopian cattle populations reflect their history of origin and admixture rather than phenotype-based distinctions. The high within-individual genetic variability observed in Ethiopian cattle represents an untapped opportunity for adaptation to changing environments and for implementation of within-breed genetic improvement schemes. Our results provide a basis for future applications of genome-wide SNP data to exploit the unique genetic makeup of indigenous cattle breeds and to facilitate their improvement and conservation.     

Genetic diversity measures of local European beef cattle breeds for conservation purposes

This study was undertaken to determine the genetic structure, evolutionary relationships, and the genetic diversity among 18 local cattle breeds from Spain, Portugal, and France using 16 microsatellites. Heterozygosities, estimates of Fst, genetic distances, multivariate and diversity analyses, and assignment tests were performed. Heterozygosities ranged from 0.54 in the Pirenaica breed to 0.72 in the Barrosã breed. Seven percent of the total genetic variability can be attributed to differences among breeds (mean F_st = 0.07; P < 0.01). Five different genetic distances were computed and compared with no correlation found to be significantly different from 0 between distances based on the effective size of the population and those which use the size of the alleles. The Weitzman recursive approach and a multivariate analysis were used to measure the contribution of the breeds diversity. The Weitzman approach suggests that the most important breeds to be preserved are those grouped into two clusters: the cluster formed by the Mirandesa and Alistana breeds and that of the Sayaguesa and Tudanca breeds. The hypothetical extinction of one of those clusters represents a 17% loss of diversity. A correspondence analysis not only distinguished four breed groups but also confirmed results of previous studies classifying the important breeds contributing to diversity. In addition, the variation between breeds was sufficiently high so as to allow individuals to be assigned to their breed of origin with a probability of 99% for simulated samples.     

Analysis of the Genetic Structure of Endangered Bovine Breeds from the Western Pyrenees Using Dna Microsatellite Markers

In the Western Pyrenees, three out of four native cattle breeds are in grave danger of extinction. Genetic variation of all four breeds was assessed by analyzing 478 animals using 11 microsatellite markers. A moderate/high within-breed variability was found, a favorable factor to consider when planning conservation and improvement programs. Interestingly, the only selected commercial breed, the Pirenaica, showed depressed heterozygosity levels and a low average number of alleles, perhaps explainable by intensive human selection exacerbated by a bottleneck effect. The Pirenaica also exhibited pronounced genetic differences and was the largest contributor of diversity among the breeds from the Western Pyrenees. Among endangered cattle breeds from this region, our results highlight the singularity of the Betizu. Geographic isolation among herds may be responsible for the large F(IS) value found in the Betizu breed. Lastly, our study suggests that the use of highly selected breeds may be one of the causes of distortion in phylogenetic analyses.     

Genetic Diversity and Relationship of Yunnan Native Cattle Breeds and Introduced Beef Cattle Breeds

In this study, random amplified polymorphic DNA (RAPD) analysis was used to estimate genetic diversity and relationship in 134 samples belonging to two native cattle breeds from the Yunnan province of China (DeHong cattle and DiQing cattle) and four introduced beef cattle breeds (Brahman, Simmental, MurryGrey, and ShortHorn). Ten primers were used, and a total of 84 bands were scored, of which 63 bands (75.0%) were polymorphic. The genetic distance matrix was obtained by proportions of shared fragment. The results indicate that the Yunnnan DeHong cattle breed is closely related to the Brahman (Bos indicus), and the Yunnan DiQing cattle breed is closely related to the Simmental, ShortHorn, and MurryGrey (Bos taurus) breeds. Our results imply that Bos indicus and Bos taurus were the two main origins of Yunnan native cattle. The results also provide the basic genetic materials for conservation of cattle resources and crossbreeding of beef cattle breeds in South China.     

中国部分地方黄牛品种线粒体D-loop区的遗传变异与进化分析

测定了13个黄牛品种125个个体的线粒体D-loop区段的全序列,包括12个中国地方黄牛品种的123个个体和德国黄牛2个个体,并进行了分析。结果显示,共检测到93个变异位点,57个单倍型,平均核苷酸差异(average number ofnucleotide differences,k)为22.708,核苷酸多样度(nucleotide diversity,π)为0.0251±0.00479,单倍型多样度(haplotypediversity,Hd)为0.888±0.026,表明我国黄牛品种遗传多样性非常丰富。构建的Neighbor-Joining进化树显示这13个品种主要分成两大类型:普通牛和瘤牛;新发现的特殊类型Ⅲ只有一个西藏阿沛甲咂牛的个体,它与牦牛D-loop序列最相近,证明西藏地区的黄牛与牦牛之间存在基因渗入现象。普通牛和瘤牛在日喀则驼峰牛中占的比例分别是64.3%和35.7%,在阿沛甲咂牛中占的比例分别是50.0%和50.0%,证明了西藏的黄牛也有瘤牛类型。云南牛品种的单倍型非常丰富证明了云南在中国黄牛起源上的重要地位;在27个中国黄牛品种中(本研究11个品种以及GenBank上的16个品种)找到了中国瘤牛的核心单倍型i1,并且对它进行了讨论。同时证明了西藏瘤牛独立于中国瘤牛核心类群的特殊性。     

Genetic diversity and relationships of endangered Spanish cattle breeds

Information on the genetic structure and variability of autochthonous livestock breeds is essential for effective conservation programs. Here we present a molecular characterization on the basis of 30 microsatellite markers of 5 Spanish endangered cattle breeds Betizu (BET), Mallorquina (MAL), Menorquina, Monchina (MON), and Serrana de Teruel (ST) and of 2 fighting bull populations, Casta Navarra (CN) and Casta Vistahermosa. The feral and critically endangered BET is divided into 2 subpopulations, one of which has exceptionally low diversity values. A low number of alleles was also observed in the island population MAL. Although the small population size and genetic drift have caused a considerable divergence between the breeds, phylogenetic analysis is in accordance with historical and geographical data. The 2 northern Spanish feral breeds BET and MON cluster together. The local fighting breed CN is relatively close to the more inbred Casta Vistahermosa, which is the progenitor of most other fighting bulls in Spain. Comparison with nonendangered breeds suggests admixture of Alpine and/or Pyrenean mountain cattle in the ST, which may contribute to the high level of linkage disequilibrium in this population.