American Cattle Research Articles

Potential emigration of Siberian cattle germplasm on Chirikof Island, Alaska

Feral cattle residing in Chirikof Island, Alaska, are relatively distinct from breeds used in commercial production in North America. However, preliminary evidence suggested that they exhibit substantial genetic relationship with cattle from Yakutian region of Siberia. Thus, our objective was to further elucidate quantify the origins, admixture and divergence of the Chirikof Island cattle relative to cattle from Siberia and USA. Subject animals were genotyped at 15 microsatellite loci. Compared with Turano-Mongolian and North American cattle, Chirikof Island cattle had similar variation, with slightly less observed heterozygosity, fewer alleles per locus and a positive fixation index. Analysis of the genetic distances revealed two primary clusters; one that contained the North American breeds and the Kazakh White head, and a second that contained the Yakutian and Kalmyk breeds, and the Chirikof population. Thus, it is suggested that Chirikof Island cattle may be a composite of British breeds emanating from North America and Turano-Mongolian cattle. A potential founder effect, consistent with historical records of the Russian-American period, may contribute to the adaptation of the Chirikof Island cattle to their harsh high-latitude environment. Further study of adaptive mechanisms manifest by these cattle is warranted.

Beyond the Branding Iron: Cattle Brands as Heritage Place Names in the State of Montana

For more than two centuries, American cattle ranchers have used hot-iron brands as the primary means of identifying and asserting ownership of their animals. American cattle brands consist of highly visible symbols containing letters, numbers, and/or images which may appear individually or in any combination. Every cattle brand symbol has a corresponding name that occurs in spoken and written (alphabetized) form. By virtue of purposeful naming strategies, cattle brands display a range of associations with other types of names. These onomastic relationships reflect underlying connections between cattle brands and various elements in their socio-cultural surroundings, and offer some fascinating insights into the history, culture, and social structure of American cattle-ranching communities. This paper specifically examines the practice of naming towns and ranches after cattle brands in the State of Montana, and explains how this phenomenon comprises a unique aspect of the region’s cultural heritage.

A new genotype of bovine leukemia virus in South America identified by NGS-based whole genome sequencing and molecular evolutionary genetic analysis.

BackgroundBovine leukemia virus (BLV) is a member of retroviridae family, together with human T cell leukemia virus types 1 and 2 (HTLV-1 and -2) belonging to the genes deltaretrovirus, and infects cattle worldwide. Previous studies have classified the env sequences of BLV provirus from different geographic locations into eight genetic groups. To investigate the genetic variability of BLV in South America, we performed phylogenetic analyses of whole genome and partial env gp51 sequences of BLV strains isolated from Peru, Paraguay and Bolivia, for which no the molecular characteristics of BLV have previously been published, and discovered a novel BLV genotype, genotype-9, in Bolivia.ResultsIn Peru and Paraguay, 42.3 % (139/328) and over 50 % (76/139) of samples, respectively, were BLV positive. In Bolivia, the BLV infection rate was up to 30 % (156/507) at the individual level. In Argentina, 325/420 samples were BLV positive, with a BLV prevalence of 77.4 % at the individual level and up to 90.9 % at herd level. By contrast, relatively few BLV positive samples were detected in Chile, with a maximum of 29.1 % BLV infection at the individual level. We performed phylogenetic analyses using two different approaches, maximum likelihood (ML) tree and Bayesian inference, using 35 distinct partial env gp51 sequences from BLV strains isolated from Peru, Paraguay, and Bolivia, and 74 known BLV strains, representing eight different BLV genotypes from various geographical locations worldwide. The results indicated that Peruvian and Paraguayan BLV strains were grouped into genotypes-1, -2, and -6, while those from Bolivia were clustered into genotypes-1, -2, and -6, and a new genotype, genotype-9. Interestingly, these results were confirmed using ML phylogenetic analysis of whole genome sequences obtained by next generation sequencing of 25 BLV strains, assigned to four different genotypes (genotypes-1, -2, -6, and -9) from Peru, Paraguay, and Bolivia. Comparative analyses of complete genome sequences clearly showed some specific substitutions, in both structural and non-structural BLV genes, distinguishing the novel genotype-9 from known genotypes.ConclusionsOur results demonstrate widespread BLV infection in South American cattle and the existence of a new BLV genotype-9 in Bolivia. We conclude that at least seven BLV genotypes (genotypes-1, -2, -4, -5, -6, -7, and -9) are circulating in South America.Electronic supplementary materialThe online version of this article (doi:10.1186/s12977-016-0239-z) contains supplementary material, which is available to authorized users.

Cross-Reactivity of Neutralizing Antibodies among Malignant Catarrhal Fever Viruses

Some members of the gamma herpesvirus genus Macavirus are maintained in nature as subclinical infections in well-adapted ungulate hosts. Transmission of these viruses to poorly adapted hosts, such as American bison and cattle, can result in the frequently fatal disease malignant catarrhal fever (MCF). Based on phylogenetic analysis, the MCF viruses (MCFV) cluster into two subgroups corresponding to the reservoir hosts’ subfamilies: Alcelaphinae/Hippotraginae and Caprinae. Antibody cross-reactivity among MCFVs has been demonstrated using techniques such as enzyme linked immunosorbent and immunofluorescence assays. However, minimal information is available as to whether virus neutralizing antibodies generated against one MCFV cross react with other members of the genus. This study tested the neutralizing activity of serum and plasma from select MCFV-infected reservoir hosts against alcelaphine herpesvirus 1 (AlHV-1) and ovine herpesvirus 2 (OvHV-2). Neutralizing antibody activity against AlHV-1 was detected in samples from infected hosts in the Alcelaphinae and Hippotraginae subfamilies, but not from hosts in the Caprinae subfamily. OvHV-2 neutralizing activity was demonstrated in samples from goats (Caprinae) but not from wildebeest (Alcelaphinae). These results show that neutralizing antibody cross reactivity is present to MCFVs within a virus subgroup but not between subgroups. This information is important for diagnosing infection with MCFVs and in the development of vaccines against MCF.

Prediction of enteric methane emission from cattle using linear and non-linear statistical models in tropical production systems

The objective of this study was to develop linear and nonlinear statistical models to predict enteric methane emission (EME) from cattle (Bos) in the tropics based on dietary and animal characteristic variables. A database from 35 publications, which included 142 mean observations of EME measured on 830 cattle, was constructed to develop EME prediction models. Several extant equations of EME developed for North American and European cattle were also evaluated for suitability of those equations in this dataset. The average feed intake and methane production were 7.7 ± 0.34 kg/day and 7.99 ± 0.39 MJ/day, respectively. The simple linear equation that predicted EME with high precision and accuracy was: methane (MJ/day) = 1.29(±0.906) + 0.878(±0.125) × dry matter intake (DMI, kg/day), [root mean square prediction error (RMSPE) = 31.0 % with 92 % of RMSPE being random error; R 2 = 0.70]. Multiple regression equation that predicted methane production slightly better than simple prediction equations was: methane (MJ/day) = 0.910(±0.746) + 1.472(±0.154) × DMI (kg/day) – 1.388(±0.451) × feeding level as a multiple of maintenace energy intake – 0.669(±0.338) × acid detergent fiber intake (kg/day), [RMSPE = 22.2 %, with 99.6 % of MSPE from random error; R 2 = 0.84]. Among the nonlinear equations developed, Mitscherlich model, i.e., methane (MJ/day) = 71.47(±22.14.6) × (1 - exp{−0.0156(±0.0051) × DMI (kg/day), [RMSPE = 30.3 %, with 97.6 % of RMSPE from random error; R 2 = 0.83] performed better than simple linear and other nonlinear models, but the predictability and goodness of fits of the equation did not improve compared with the multiple regression models. Extant equations overestimated EME, and many extant models had low accuracy and precision. The equations developed in this study will be useful for improved estimates of national methane inventory preparation and for a better understanding of dietary factors influencing EME for tropical cattle feeding systems.

Bovine thoracic ultrasonography

Bovine respiratory disease (BRD) continues to be the major animal health concern facing the North American cattle feeding industry. Despite improvements in technologies and the development of new antimicrobials, morbidity and mortality rates have remained flat or even increased. Thoracic ultrasonography (TUS) is a technology that has shown promise as a chute-side diagnostic tool for BRD. Degree of lung consolidation, as determined by TUS, has been negatively correlated to clinical outcome in cattle pulled for signs attributable to BRD and not treated with antimicrobials (negative controls). Thoracic ultrasonography is relatively simple to perform, and many of the available ultrasound machines and probes used for bovine reproductive ultrasonography can also be used to examine the lungs and pleura. While the procedures and techniques for large-scale use in a production setting remain to be validated, practitioners may currently be able to use the technology to add accuracy and value to their recommendations for case management of individual animals.

The effect of storage temperature and percentage of condensed distillers solubles on the shelf-life of distillers wet grains stored aerobically

Distillers wet grains with solubles (DWGS) are widely used as a supplemental protein source in North American cattle rations. However, due to its short shelf-life, its use is limited to feedlots within close proximity of an ethanol production plant. It is known that the shelf-life of DWGS in the summer diminishes drastically compared to in the winter. This effect is primarily due to temperature, which drives mold growth in high moisture feedstocks. The purpose of this study was to understand and quantify the effect of temperature (10, 20, and 25 °C) and condensed distillers solubles (CDS) levels [0%, 20% and 30%] on the shelf-life of DWGS under warm and cool aerobic storage conditions. Sample conditions which indicate shelf-life and product deterioration such as moisture content (m.c.), pH, fat acidity (FA), fungal growth and mycotoxin levels were measured in the DWGS samples before and after seven days of storage under three temperature levels (10, 20, and 25 °C). It was found that changes in temperature had the most significant effect on sample conditions (P < 0.05). After seven days of storage, m.c. and water activity (aw) decreased with increase in temperature. In comparison, it was determined that FA, pH, fungal growth and mycotoxin levels increased with temperature after seven days of storage. Also, FA and CFU increased with increase in CDS level in DWGS. It was concluded that after seven days of storage at both warm and cool aerobic storage conditions, FA, aflatoxin, fumonisin and zearalenone levels increased. DWGS deteriorated less at 10 °C than at 20 °C and 25 °C, likewise less deterioration in 0% CDS than in 20% and 30% was noted.

Scoping review to identify potential non-antimicrobial interventions to mitigate antimicrobial resistance in commensal enteric bacteria in North American cattle production systems.

A scoping review was conducted to identify modifiable non-antimicrobial factors to reduce the occurrence of antimicrobial resistance in cattle populations. Searches were developed to retrieve peer-reviewed published studies in animal, human and in vitro microbial populations. Citations were retained when modifiable non-antimicrobial factors or interventions potentially associated with antimicrobial resistance were described. Studies described resistance in five bacterial genera, species or types, and 40 antimicrobials. Modifiable non-antimicrobial factors or interventions ranged widely in type, and the depth of evidence in animal populations was shallow. Specific associations between a factor or intervention with antimicrobial resistance in a population (e.g. associations between organic systems and tetracycline susceptibility in E. coli from cattle) were reported in a maximum of three studies. The identified non-antimicrobial factors or interventions were classified into 16 themes. Most reported associations between the non-antimicrobial modifiable factors or interventions and antimicrobial resistance were not statistically significant (P > 0·05 and a confidence interval including 1), but when significant, the results were not consistent in direction (increase or decrease in antimicrobial resistance) or magnitude. Research is needed to better understand the impacts of promising modifiable factors or interventions on the occurrence of antimicrobial resistance before any recommendations can be offered or adopted.

Spread of vaccinia virus to cattle herds, Argentina, 2011.

Spread of vaccinia virus to cattle herds, Argentina, 2011.

The Coupling of South American Soybean and Cattle Production Frontiers: New Challenges for Conservation Policy and Land Change Science

Different drivers and places of land use change in South America have often been studied in isolation. Evidence suggests, however, that in many instances, both places and drivers are becoming increasingly interconnected. The growing diversification and internationalization of agricultural commodity chains is creating new linkages across production frontiers and sectors that have important implications for conservation. In this article, we explore the implications of the sectoral and geographical coupling of soybean and cattle production frontiers for forest conservation in South America, with particular attention to the potential for policy-induced deforestation leakage. We conclude that the existence of coupled frontiers creates a need for more actor-centered approaches to conservation policy and research.

A novel Ehrlichia genotype strain distinguished by the TRP36 gene naturally infects cattle in Brazil and causes clinical manifestations associated with ehrlichiosis

A novel Ehrlichia genotype most closely related to E. canis was reported in North American cattle in 2010, and a similar agent was subsequently identified in the hemolymph of Brazilian Rhipicephalus (Boophilus) microplus ticks and isolated in 2012. The purpose of this study was to determine whether this or other novel ehrlichial agents naturally infect Brazilian cattle. Using PCR targeting the genus-conserved dsb gene, DNA from this novel ehrlichial agent in Brazilian cattle was detected. Attempts to isolate the organism in vitro were performed using DH82 cells, but morulae and ehrlichial DNA could only be detected for approximately one month. In order to further molecularly characterize the organism, PCR was performed using primers specific for multiple E. canis genes (dsb, rrs, and trp36). Sequence obtained from the conserved rrs and dsb genes demonstrated that the organism was 99–100% identical to the novel Ehrlichia genotypes previously reported in North American cattle (rrs gene) and Brazilian ticks (rrs and dsb genes). However, analysis of the trp36 gene revealed substantial strain diversity between these Ehrlichia genotypes strains, including divergent tandem repeat sequences. In order to obtain preliminary information on the potential pathogenicity of this ehrlichial agent and clinical course of infection, a calf was experimentally infected. The calf showed clinical signs of ehrlichiosis, including fever, depression, lethargy, thrombocytopenia, and morulae were observed in peripheral blood monocytes. This study reports a previously unrecognized disease-causing Ehrlichia sp. in Brazilian cattle that is consistent with the genotype previously described in North America cattle and ticks from Brazil. Hence, it is likely that this is the organism previously identified as Ehrlichia bovis in Brazil in 1982. Furthermore, we have concluded that strains of these Ehrlichia genotypes can be molecularly distinguished by the trp36 gene, which has been widely utilized to define E. canis strain diversity.

Revisiting AFLP fingerprinting for an unbiased assessment of genetic structure and differentiation of taurine and zebu cattle.

BackgroundDescendants from the extinct aurochs (Bos primigenius), taurine (Bos taurus) and zebu cattle (Bos indicus) were domesticated 10,000 years ago in Southwestern and Southern Asia, respectively, and colonized the world undergoing complex events of admixture and selection. Molecular data, in particular genome-wide single nucleotide polymorphism (SNP) markers, can complement historic and archaeological records to elucidate these past events. However, SNP ascertainment in cattle has been optimized for taurine breeds, imposing limitations to the study of diversity in zebu cattle. As amplified fragment length polymorphism (AFLP) markers are discovered and genotyped as the samples are assayed, this type of marker is free of ascertainment bias. In order to obtain unbiased assessments of genetic differentiation and structure in taurine and zebu cattle, we analyzed a dataset of 135 AFLP markers in 1,593 samples from 13 zebu and 58 taurine breeds, representing nine continental areas.ResultsWe found a geographical pattern of expected heterozygosity in European taurine breeds decreasing with the distance from the domestication centre, arguing against a large-scale introgression from European or African aurochs. Zebu cattle were found to be at least as diverse as taurine cattle. Western African zebu cattle were found to have diverged more from Indian zebu than South American zebu. Model-based clustering and ancestry informative markers analyses suggested that this is due to taurine introgression. Although a large part of South American zebu cattle also descend from taurine cows, we did not detect significant levels of taurine ancestry in these breeds, probably because of systematic backcrossing with zebu bulls. Furthermore, limited zebu introgression was found in Podolian taurine breeds in Italy.ConclusionsThe assessment of cattle diversity reported here contributes an unbiased global view to genetic differentiation and structure of taurine and zebu cattle populations, which is essential for an effective conservation of the bovine genetic resources.

Worldwide Patterns of Ancestry, Divergence, and Admixture in Domesticated Cattle

The domestication and development of cattle has considerably impacted human societies, but the histories of cattle breeds and populations have been poorly understood especially for African, Asian, and American breeds. Using genotypes from 43,043 autosomal single nucleotide polymorphism markers scored in 1,543 animals, we evaluate the population structure of 134 domesticated bovid breeds. Regardless of the analytical method or sample subset, the three major groups of Asian indicine, Eurasian taurine, and African taurine were consistently observed. Patterns of geographic dispersal resulting from co-migration with humans and exportation are recognizable in phylogenetic networks. All analytical methods reveal patterns of hybridization which occurred after divergence. Using 19 breeds, we map the cline of indicine introgression into Africa. We infer that African taurine possess a large portion of wild African auroch ancestry, causing their divergence from Eurasian taurine. We detect exportation patterns in Asia and identify a cline of Eurasian taurine/indicine hybridization in Asia. We also identify the influence of species other than Bos taurus taurus and B. t. indicus in the formation of Asian breeds. We detect the pronounced influence of Shorthorn cattle in the formation of European breeds. Iberian and Italian cattle possess introgression from African taurine. American Criollo cattle originate from Iberia, and not directly from Africa with African ancestry inherited via Iberian ancestors. Indicine introgression into American cattle occurred in the Americas, and not Europe. We argue that cattle migration, movement and trading followed by admixture have been important forces in shaping modern bovine genomic variation.

Meta-Analysis of Mitochondrial DNA Reveals Several Population Bottlenecks during Worldwide Migrations of Cattle

Several studies have investigated the differentiation of mitochondrial DNA in Eurasian, African and American cattle as well as archaeological bovine material. A global survey of these studies shows that haplogroup distributions are more stable in time than in space. All major migrations of cattle have shifted the haplogroup distributions considerably with a reduction of the number of haplogroups and/or an expansion of haplotypes that are rare or absent in the ancestral populations. The most extreme case is the almost exclusive colonization of Africa by the T1 haplogroup, which is rare in Southwest Asian cattle. In contrast, ancient samples invariably show continuity with present-day cattle from the same location. These findings indicate strong maternal founder effects followed by limited maternal gene flow when new territories are colonized. However, effects of adaptation to new environments may also play a role.

Curious stories surrounding the discovery and development of conventional antithrombotics

ZusammenfassungDie Entdeckung eines therapeutischen Effektes war früher meist ein Zufallsereignis. Vielfach war der Weg bis zur Anwendung lang und steinig und nicht selten von merkwürdigen Geschichten begleitet, so bei den Antithrombotika Heparin, Aspirin und Warfarin.Heparin: Wem gebührt die Anerkennung als Entdecker? Dem Studenten Jay McLean, der neben den gesuchten thromboplastisch wirksamen Cephalin-Komponenten zufällig eine gerinnungshemmende Komponente fand? Oder seinem Chef, der die „zufällige Entdeckung“ McLeans später aufgriff und eben-falls gerinnungshemmende Komponenten isolierte, die sich jedoch chemisch von den McLean´schen unterschieden und zur Ausgangssubstanz des heutigen Heparins wurden?Aspirin: Als schmerz- und fiebersenkendes Mittel längst bekannt, erfuhr es eine zweite Karriere in der kardiovaskulären Medizin. Erst 1967 erkannte man, dass die Plättchenaktivität inhibiert wird. Die zweite Karriere begann mit der Zulassung für TIA und Herzinfarkt anfangs 1980. Bis dato unbekannt war die Geschichte des Dr. Craven, der bereits 1950 in „obskuren“ Zeitschriften seine Beobachtung publizierte, dass alle seine unter Aspirin stehenden Patienten von Herzinfarkt verschont blieben.Warfarin:Um 1920 starben tausende Rinder in Nordamerika an inneren Blutungen. Die Ursache fand man im Verzehr des gelagerten „sweet clover“. Erst nach Jahren hatte man die Erklärung: die Umwandlung des ungiftigen Coumarin im Heu in das gerinnungshemmende Dicoumarol durch Pilzinfektion. Bald folgte die Synthese und damit auch der klinische Einsatz als Antithrombotikum. Viel größeren Erfolg aber hatte die Substanz als Rattengift mit dem Namen Warfarin. Die erneute Anwendung beim Menschen erfolgte erst wieder, nachdem ein Soldat seinen Suizidver-such durch Vitamin K-Gabe überstanden hatte.

Accuracies of direct genomic breeding values in Hereford beef cattle using national or international training populations1

The objective of this study was to estimate accuracies of direct genomic breeding values (DGV) for nationally evaluated traits of 1,081 American (AMH), 100 Argentine (ARH), 75 Canadian (CAH), and 395 Uruguayan (URH) Hereford animals genotyped using the Illumina BovineSNP50 BeadChip. Deregressed EBV (DEBV) were used as observations in a weighted analysis to derive DGV using BayesB and BayesC methods. The AMH animals were clustered into 4 groups, using either K-means or random clustering. Cross validation was performed with the group not used in training providing validation of the accuracies of estimated DGV. Genomic predictions were also evaluated for AMH animals by training on older animals and validating on younger animals. Bivariate animal models were used for each trait to estimate genetic correlations between DEBV and DGV. Genomic predictions were separately evaluated for foreign animals from each country using marker estimates from training on AMH or pooled international data. Pedigree estimated breeding values were developed for AMH animals, using traditional, pedigree-based BLUP (PBLUP) for comparison purposes. Using BayesB (BayesC) method, the average simple correlations between DGV and DEBV in AMH animals was 0.24 (0.21), 0.39 (0.36), and 0.32 (0.30) when training and validation sets were formed by K-means clustering, random allocation or year of birth of the animals, respectively. Genetic correlations between DEBV and DGV ranged from 0.20 (0.18) to 0.52 (0.45) in AMH animals. The DGV from BayesB were more accurate than from BayesC for most traits in AMH animals. Genomic predictions for foreign animals were less accurate than those obtained in AMH animals. Among foreign animals, genomic predictions were more accurate for CAH animals, which reflect the greater use of AMH sires in CAH in comparison with ARH and URH populations. Small changes in accuracies of DGV were observed for foreign animals by using admixed training populations. On average, genomic predictions across countries were more accurate for CAH and URH animals using BayesB. On average, accuracies of genomic predictions using BayesB (BayesC) method were 66% (55%) greater than those obtained from PBLUP. These results demonstrate the feasibility of developing DGV for American Hereford beef cattle. However, foreign breeders, especially South American Hereford breeders, need to genotype more animals to obtain more accurate genomic predictions.

Genetic diversity and differentiation of exotic and American commercial cattle breeds raised in Brazil

The Brazilian cattle population is mainly composed of breeds of zebuine origin and their American derivatives. Comprehensive knowledge about the genetic diversity of these populations is fundamental for animal breeding programs and the conservation of genetic resources. This study aimed to assess the phylogenetic relationships, levels of genetic diversity, and patterns of taurine/zebuine admixture among 9 commercial cattle breeds raised in Brazil. Analysis of DNA polymorphisms was performed on 2965 animals using the 11 microsatellite markers recommended by the International Society of Animal Genetics. High genetic diversity was detected in all breeds, even though significant inbreeding was observed within some. Differences among the breeds accounted for 14.72% of the total genetic variability, and genetic differentiation was higher among taurine than among zebuine cattle. Of note, Nelore cattle presented with high levels of admixture, which is consistent with the history of frequent gene flow during the establishment of this breed in Brazil. Furthermore, significant genetic variability was partitioned within the commercial cattle breeds formed in America, which, therefore, comprise important resources of genetic diversity in the tropics. The genetic characterization of these important Brazilian breeds may now facilitate the development of management and breeding programs for these populations.

Genetic Footprints of Iberian Cattle in America 500 Years after the Arrival of Columbus

BackgroundAmerican Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, and may have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources.Methodology/Principal FindingsWe sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu.Conclusions/SignificanceNearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental conditions.

Evaluation of BTA1 and BTA5 QTL Regions for Growth and Carcass Traits in American and Korean Cattle.

Previously identified QTL regions on BTA1 and BTA5 were investigated to validate the QTL regions and to identify candidate genes for growth and carcass traits in commercial cattle populations from the USA and Korea. Initially, a total of 8 polymorphic microsatellite (MS) markers in the BTA1 and 5 QTL regions were used for Chi-square tests to compare the frequencies of individual alleles between high and low phenotypic groups for the US (Michigan Cattleman’s Association/Michigan State University; MCA/MSU) cattle. For a subsequent study, 24 candidate genes containing missense mutations and located within the QTL regions based on bovine genome sequence data were analyzed for genotyping in the two commercial cattle populations. Re-sequencing analyses confirmed 18 public missense SNPs and identified 9 new SNPs. Seventeen of these SNPs were used for genotyping of the MCA/MSU cattle (n = 98) and Korean native cattle (n = 323). On BTA1, UPK1B, HRG, and MAGEF1 polymorphisms residing between BM1312 and BMS4048 were significantly associated with growth and carcass traits in one or both of the MCA/MSU and Korean populations. On BTA5, ABCD2, IL22 and SNRPF polymorphisms residing between BL4 and BR2936 were associated with marbling and backfat traits in one or both of the MCA/MSU and Korean cattle populations. These results suggested that BTA 1 and 5 QTL regions may be segregating in both Korean Hanwoo and USA commercial cattle populations and DNA markers tested in this study may contribute to the identification of positional candidate genes for marker-assisted selection programs.

Is Trypanosoma vivax genetically diverse?

Is Trypanosoma vivax genetically diverse?