9 research outputs found

    Genome-Wide Association Study in Mexican Holstein Cattle Reveals Novel Quantitative Trait Loci Regions and Confirms Mapped Loci for Resistance to Bovine Tuberculosis

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    Bovine tuberculosis (bTB) is a disease of cattle that represents a risk to public health and causes severe economic losses to the livestock industry. Recently, genetic studies, like genome-wide association studies (GWAS) have greatly improved the investigation of complex diseases identifying thousands of disease-associated genomic variants. Here, we present evidence of genetic variants associated with resistance to TB in Mexican dairy cattle using a case-control approach with a selective DNA pooling experimental design. A total of 154 QTLRs (quantitative trait loci regions) at 10% PFP (proportion of false positives), 42 at 5% PFP and 5 at 1% PFP have been identified, which harbored 172 annotated genes. On BTA13, five new QTLRs were identified in the MACROD2 and KIF16B genes, supporting their involvement in resistance to bTB. Six QTLRs harbor seven annotated genes that have been previously reported as involved in immune response against Mycobacterium spp: BTA (Bos taurus autosome) 1 (CD80), BTA3 (CTSS), BTA 3 (FCGR1A), BTA 23 (HFE), BTA 25 (IL21R), and BTA 29 (ANO9 and SIGIRR). We identified novel QTLRs harboring genes involved in Mycobacterium spp. immune response. This is a first screening for resistance to TB infection on Mexican dairy cattle based on a dense SNP (Single Nucleotide Polymorphism) chip

    Genomic variability in Mexican chicken population using copy number variants

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    Background: Copy number variations are genome polymorphism that influence phenotypic variation and are an important source of genetic variation in populations. The aim of this study was to investigate genetic variability in the Mexican Creole chicken population using CNVs. Results: The Hidden Markov Model of the PennCNV software detected a total of 1924 CNVs in the genome of the 256 samples processed with Axiom\uc2\uae Genome-Wide Chicken Genotyping Array (Affymetrix). The mapped CNVs comprised 1538 gains and 386 losses, resulting at population level in 1216 CNV regions (CNVRs), of which 959 gains, 226 losses and 31 complex (i.e. containing both losses and gains). The CNVRs covered a total of 47 Mb of the whole genome sequence length, corresponding to 5.12% of the chicken galGal4 autosome assembly. Conclusions: This study allowed a deep insight into the structural variation in the genome of unselected Mexican chicken population, which up to now has not been genetically characterized. The genomic study disclosed that the population, even if presenting extreme morphological variation, cannot be organized in differentiated genetic subpopulations. Finally this study provides a chicken CNV map based on the 600 K SNP chip array jointly with a genome-wide gene copy number estimates in a native unselected for more than 500 years chicken population

    Antecedents of labor shortage in the rural hospitality industry: a comparative study of employees and employers

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    Although the role of human capital in the hospitality sector is critical, the industry faces challenges in attracting workers with a poor industry image frequently mentioned regarding labor shortages. This research paper attempts to investigate the factors influencing labor shortages by presenting the perspectives of employees and employers.Design/methodology/approachPrecisely 232 rural hospitality industry employees (n = 128) and employers (n = 104) in Northern Italy were surveyed using a written close-ended online survey and a quantitative research design as part of a convenience sampling approach. For hypotheses testing, Spearman's rho was used.FindingsA relationship between the shortage of professional workers and a variety of factors was found, including professional, digital, social and green skills, industry-intrinsic characteristics and symbolic image attributes of the industry. The findings show that some factors are more important for employees, while others are more significant for employers.Practical implicationsThis study demonstrates several practical implications for the hospitality sector by addressing the under-researched stakeholder group of existing hospitality employees, e.g. improving working conditions, reduction of manual operations through digital technologies, realistic career planning, employer branding, identification of skill deficiencies and provision of specialized trainings.Originality/valueMost research on labor shortages in the hospitality industry has focused on the perspective of either employees or employers. This study compares both perspectives, including the industry image, to gain a realistic picture of the relevant factors for a rural tourism destination in Northern Italy

    Grossbritannien & China 1793 - 1842

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    1792/93 stellte, den Zeitgenossen wohl eher unbewusst, ein entscheidendes Datum für die Geschichte Chinas dar. Nach dem Aufbruch von Lord Macarnteys Gesandtschaft mit unter anderem dem Ziel, wirtschaftliche Vorteile für Grossbritannien in China zu sichern, verschlechterten sich die Beziehungen zunehmend bis es letzten Endes zum Ersten Opiumkrieg 1839-1842 kam. Innerhalb dieses zeitlichen Rahmens ist eine deutliche Veränderung der Beziehungen zwischen beiden Staaten zu erkennen, welche sich immer mehr zu Gunsten Grossbritanniens entscheiden soll. Chinas Handelssystem, das so genannte Canton-System, wurde im Lauf der ersten Hälfte des 19. Jahrhunderts zunehmend kritisiert und versucht zu umgehen, was den Briten dank Piraterie und Schmuggel auch hinreichend gelang. Jedoch schien das System sich zu halten - und tatsächlich blieb es zumindest auf dem Papier bis zum Ersten Opiumkrieg intakt - und wurde letztlich durch den steigenden Opiumhandel derart unterwandert, dass die Existenz hinfällig wurde. Die Dimension wurde politisch, als Theorien des Freien Handels und der Souveränität der Staaten den Diskurs bestimmten, und Grossbritannien zu militärischen Aktionen gegen seinen Handelspartner führten. Der chinesische Staat schien ohnmächtig, den wachsenden Bedürfnissen nachzukommen, nicht zuletzt dadurch dass hier zwei Ideologien aufeinanderstiessen, welche am Ende nicht mehr vereinbar waren. Die blosse Idee eines gleichgestellten "Barbaren aus dem Westen" war nicht mit dem chinesischen Denken vereinbar und es kam wie es kommen musste: zu bewaffneten Auseinandersetzungen bei welchen China das Nachsehen hatte

    Effects of crossbreeding on milk production and growth characteristics in dual-purpose cattle in humid tropics

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    Crossbreeding effects were evaluated in three dual purpose bovine sub-populations in the tropics, and 5,040 lactations, 4,429 birth weights and adjusted weights at 205 [3,878], 365 [3,017] and 540 [2,276] days (PN, P205, P365 y P540, respectively) from Zebu cattle (CE) and its crosses with Holstein (HS), Brown Swiss (SP) and Simmental (SM). Additive direct breed effects (PG), heterozygosity (HT) and recombination loss (RC) were estimated by a regression analysis within breed group with mixed models. Evaluated fixed effects were herd and year of freshening, season, lactation number and offspring gender for milk yield (PL) and herd, birth year and season for growth traits. Random effects for PL were direct (animal) and permanent environment and for growth traits were genetic direct and maternal and permanent maternal environmental effects. PG/HS, PG/SP y HT/SM had effects (P<0.10) on PL while PG/SP, PG/SM, HT/SM and RC/HS on PN. PG/HS y PG/SP presented effects (P<0.10) on P205, P365 and P540 while PG/SM only on P205. HT and RC had effects (P<0.10) on P205, P365 y P540 for all crosses. Results hereby presented will allow the formulation of strategies for the use of additive and non-additive genetic effects of the crossbred populations present in the Mexican humid tropical regions

    Bimodality and the genetics of milk flow traits in the Italian Holstein-Friesian breed

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    The overall goal of this study was to investigate milk flow traits in Italian Holstein-Friesian cows and, in particular, the bimodality of milk flow, defined as delayed milk ejection at the start of milking. Using a milkometer, 2,886 records were collected from 133 herds in northern Italy from 2001 to 2007. All records included 5 time-period measurements for milk flow, somatic cell score (SCS), milk yield, 8 udder type traits, and the presence or absence of bimodality in milk flow. Genetic parameters were estimated using linear animal models for continuous traits such as milk flow, udder type, SCS, and milk production, whereas bimodality was analyzed as a categorical trait. With the exception of decreasing time (which had a very small heritability value of 0.06), heritability values for milk flow traits were moderate, ranging from 0.10 (ascending time) to 0.41 (maximum milk flow). In addition, moderate to high genetic correlations were estimated between total milking time and other time measures (from 0.78 to 0.87), and among time flow traits (from 0.62 to 0.91). The decreasing time was the trait most genetically correlated with udder type traits, with correlation values of 0.92 with rear udder height, 0.85 with rear udder width, and 0.73 with teat placement. Large udders with strong attachments were also associated with greater milk production. Heritability estimated for bimodality was 0.43, and its genetic correlation with milk flow traits and SCS indicated a sizable genetic component underlying this trait. Bimodality was negatively associated with milk production; shorter milking times and greater peak milk levels were genetically correlated with more frequent bimodal flows, indicating that faster milk release would result in an increase in bimodal patterns. The negative genetic correlation of bimodality with SCS (-0.30) and the genetic correlation between milk flow traits and SCS suggest that the relationship between milkability and SCS is probably nonlinear and that intermediate flow rates are optimal with respect to mastitis susceptibility. Quicker milk flow over a shorter period would increase the frequency of bimodal curves in milking, whereas the correlation between bimodality and both ascending and descending time was less clear

    Looking at genetic structure and selection signatures of the Mexican chicken population using single nucleotide polymorphism markers

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    Genetic variation enables both adaptive evolutionary changes and artificial selection. Genetic makeup of populations is the result of a long-term process of selection and adaptation to specific environments and ecosystems. The aim of this study was to characterize the genetic variability of M\ue9xico's chicken population to reveal any underlying population structure. A total of 213 chickens were sampled in different rural production units located in 25 states of M\ue9xico. Genotypes were obtained using the Affymetrix Axiom\uae 600 K Chicken Genotyping Array. The Identity by Descent (IBD) and the principal components analysis (PCA) were performed by SVS software on pruned single nucleotide polymorphisms (SNPs). ADMIXTURE analyses identified 3 ancestors and the proportion of the genetic contribution of each of them has been determined in each individual. The results of the Neighbor-Joining (NJ) analysis resulted consistent with those obtained by the PCA. All methods utilized in this study did not allow a classification of M\ue9xican chicken in distinct clusters or groups. A total of 3,059 run of homozygosity (ROH) were identified and, being mainly short in length (&lt;4 Mb), these regions are indicative of a low inbreeding level in the population. Finally, findings from the ROH analysis indicated the presence of natural selective pressure in the population of M\ue9xican chicken. The study indicates that the M\ue9xican chicken clearly appear to be a unique creole chicken population that was not subjected to a specific artificial selection. Results provide a genetic knowledge that can be used as a basis for the genetic management of a unique and very large creole population, especially in the view of using it in production of hybrids to increase the productivity and economic revenue of family farming agriculture, which is widely present in M\ue9xico

    Genomic and genetic variability of six chicken populations using single nucleotide polymorphism and copy number variants as markers

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    Genomic and genetic variation among six Italian chicken native breeds (Livornese, Mericanel della Brianza, Milanino, Bionda Piemontese, Bianca di Saluzzo and Siciliana) were studied using single nucleotide polymorphism (SNP) and copy number variants (CNV) as markers. A total of 94 DNA samples genotyped with Axiom\uae Genome-Wide Chicken Genotyping Array (Affymetrix) were used in the analyses. The results showed the genetic and genomic variability occurring among the six Italian chicken breeds. The genetic relationship among animals was established with a principal component analysis. The genetic diversity within breeds was calculated using heterozygosity values (expected and observed) and with Wright\u2019s F-statistics. The individual-based CNV calling, based on log R ratio and B-allele frequency values, was done by the Hidden\u2013Markov Model (HMM) of PennCNV software on autosomes. A hierarchical agglomerative clustering was applied in each population according to the absence or presence of definite CNV regions (CNV were grouped by overlapping of at least 1 bp). The CNV map was built on a total of 1003 CNV found in individual samples, after grouping by overlaps, resulting in 564 unique CNV regions (344 gains, 213 losses and 7 complex), for a total of 9.43 Mb of sequence and 1.03% of the chicken assembly autosome. All the approaches using SNP data showed that the Siciliana breed clearly differentiate from other populations, the Livornese breed separates into two distinct groups according to the feather colour (i.e. white and black) and the Bionda Piemontese and Bianca di Saluzzo breeds are closely related. The genetic variability found using SNP is comparable with that found by other authors in the same breeds using microsatellite markers. The CNV markers analysis clearly confirmed the SNP results

    Evaluaci&#243;n morfol&#243;gica de gallinas de traspatio mexicanas (Gallus gallus domesticus) = Evaluaci&#243;n morfol&#243;gica de gallinas de traspatio mexicanas (Gallus gallus domesticus)

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    The objective was to evaluate some morphological characteristics of backyard chickens (n= 255) coming from 65 rural production units located in 52 municipalities of 18 States of the Mexican Republic. The statistical model included sex, state, and municipality within state. Sex affected all the response variables (P<0.0001), except massiveness index (P=0.3369). State affected all the response variables (P<0.0001) and municipality was only important for wingspan (P<0.0001), body weight (P<0.0271) and stockiness index (P<0.0267). Male chickens had greater (P<0.0001) body length (4.85 cm more), wingspan (5.66 cm more), breast circumference (2.94 cm more), shank length (1.73 cm more), body weight (0.65 kg more) and massiveness index (0.99 percentage points) than female chickens. Body weight increased 126 g (P<0.01) in males and 61 g in females (P<0.01) for each centimeter increment in breast circumference. Body weight showed to be moderately correlated (P<0.01) with body length (r= 0.65), wing span (r= 0.49), length of the shank (r= 0.67) and highly correlated with breast circumference (r= 0.76 in males). The Mexican backyard chicken presented significant morphological differences between males and females for traits studied, except for massiveness index
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