Mestrado em Zootecnia (EVZ)
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Navegando Mestrado em Zootecnia (EVZ) por Por Orientador "Carmo, Adriana Santana do"
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Item Impacto da seleção de touros pelo mérito genético para fertilidade na eficiência reprodutiva de rebanhos Leiteiros(Universidade Federal de Goiás, 2020-02-04) Santos, Marcello Mamedes dos; Carmo, Adriana Santana do; http://lattes.cnpq.br/0782572407995106; Okada, Eliane Sayuri Miyagi; Peres, Rogerio Fonseca Guimaraes; Carmo, Adriana Santana doThe widespread use of artificial insemination favored that different genotypes were distributed in different regions around the world. The lack of adaptation to some environmental conditions can cause an effect called genotype x environment interaction, especially in polygenic traits, causing changes in animal performance. Thus, the objective of this study was to evaluate and validate the effect of daughter pregnancy rate (DPR) based sire selection on the fertility of the national herds, contributing to the good direction in the genetic improvement of Holstein cows. Reports about performance reproductive information were collected from six herds located in three different states. The properties were selected based on the following criteria: a) milk production in feedlot systems, b) at least 300 lactating cows, c) use of fixed time artificial insemination in female reproductive management and d) participation in the program of genetic improvement of the Holstein breed. Variance analysis was performed to assess the impact of different categories of DPR and CCR (cow conception rate) on the number of days open in the herd. All statistical analyses were performed using custom packages and scripts of the R program. Although the results are not statistically significant (P <0.05), the decrease in open days and the increase in conception rates have a favorable impact on the profitability of production systems. Pearson's correlation between the RPD and RCC groups is 88%, which shows that bulls with high RPD mostly have RCC of the same magnitude.Item Marcadores moleculares na identificação de corridas de homozigose e endogamia nas raças curraleiro pé-duro e pantaneiro(Universidade Federal de Goiás, 2021-11-25) Santos, Marcelo Fernandes dos; Magnabosco, Claudio Ulhoa; http://lattes.cnpq.br/1852112832119187; Rey, Fernando Sebastián Baldi; http://lattes.cnpq.br/2142265309634106; Carmo, Adriana Santana do; http://lattes.cnpq.br/0782572407995106; Carmo, Adriana Santana do; Freitas, Thais Miranda Silva; Leite, Carla Daniela SuguimotoThe runs of homozygosity (ROHs) can be used to estimate more accurate population parameters and genomic regions under selection in different species and breeds. Therefore, this approach can be used in locally adapted breeds to identify genes of economic interest and estimate autozygosity, enabling the optimization of selection and mating strategies and mitigating their extinction risk. The objective of this work is to identify and characterize the ROHs present in locally adapted breeds Curraleiro Pé-Duro (CPD) and Pantaneiro (PANT) in order to identify genes under selection and estimate their inbreeding coefficient (FROH). The ROHs were identified in 126 and 35 animals of the CPD and PANT breeds, respectively, with data from 54,000 SNP markers. For the identification of ROHs, the following criteria were used: a) sliding window of 50 SNPs, b) minimum number of 100 consecutive SNPs in each ROH, c) minimum length of 1 Mb, c) maximum interval between homozygous consecutive SNPs of 0, 5 Mb, d) maximum of five SNPs with absent genotypes, 1083 and 140 ROHs were found in the CPD and PANT breeds, respectively, and that the predominant pattern of ROHs in the studied breeds are those of medium to long size, which demonstrates recent events of autozygosity. Six islands of homozygosity were identified in both breeds on autosomal chromosomes 6, 8, 10, 13, 14 and 17. Genes and QTLs previously related to traits of interest are located in the segments found, highlighting QTLs associated with production and quality traits of milk (57%), as those involved in the content of proteins such as caseins and genes associated with the immune system, such as the genes of the beta defensin family. The estimated inbreeding coefficient showed that both breeds have low autozygosity (2-4%), which differs from what is expected for populations with a reduced genetic base such as those studied. The present work identified six homozygous islands in common in the Curraleiro Pé-Duro and Pantaneiro breeds, located in genomic regions previously reported to be associated with characteristics of economic interest, such as disease resistance and milk protein content, which can be considered candidate regions the selection. The inbreeding coefficient estimated based on the ROHs showed that inbreeding is low (2 to 4%) in the studied populations, diverging from what was expected in small populations.Item Identificação de assinaturas de seleção e variações no número de cópias em bovinos da raça Curraleiro Pé-Duro(Universidade Federal de Goiás, 2020-02-27) Teixeira, Ana Lúcia Coutinho; Mascioli, Arthur dos Santos; http://lattes.cnpq.br/6557055478323026; Carmo, Adriana Santana do; http://lattes.cnpq.br/0782572407995106; Carmo, Adriana Santana do; Hellmeister Filho, Paulo; Freitas, Thais Miranda SilvaThe use of new molecular technologies in animal production has grown significantly in recent years, as it allows us to understand the genetic architecture of the traits of interest. Thus, the present work aimed to identify the selection signatures and the copy number variations (CNVs) present in Curraleiro Pé-Duro (CPD), in order to identify genes related to the productive and adaptive capacity of this breed. For this purpose, Illumina® BovineHD BeadChip genotypes of 120 CPD cattle from 20 different properties were used. For selection signature detection, the quality control of SNPs was performed based on the SNP and sample call rate equal to or greater than 90% and SNPs with minor allelic frequency less than 3% using the software Plink. The construction of chromosomal haplotypes was performed using the Beagle software. Signatures were identified by the following methodologies: Haplotype Integration Score (iHS), Extended Haplotype Homozygosis (EHH) and Long Range Haplotype Test (LRH). The identification of CNVs was performed using PennCNV software, adjusting the Guanine and Cytosine (GC) content of a 500 base pair (bp) genomic window. Quality control was performed using LRR standard deviation less than 0.3, BAF standard deviation less than 0.01 and wave factor less than 0.05, samples with more than 150 CNVs and markers smaller than 5,000 bp has been removed. The identification of selection signatures proved to be effective in identifying genomic regions associated with production traits, and they are mainly related to adaptability, as they are related to thermotolerance and disease resistance. CNVs are in regions of the genome that harbor genes related to thermotolerance, reproduction and negative energy balance. The results found in both studies reinforce regions of the BTA 20 chromosome as potential candidates for the selection of these characteristics.