Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-10-26T13:23:58Z No. of bitstreams: 2 camila_tangari_meira.pdf: 312940 bytes, checksum: a4627c11344e9979ceee55d723fadc4a (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-10-26T13:24:42Z (GMT) No. of bitstreams: 2 camila_tangari_meira.pdf: 312940 bytes, checksum: a4627c11344e9979ceee55d723fadc4a (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Made available in DSpace on 2015-10-26T13:24:42Z (GMT). No. of bitstreams: 2 camila_tangari_meira.pdf: 312940 bytes, checksum: a4627c11344e9979ceee55d723fadc4a (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2010 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Objetivou-se com este estudo avaliar um conjunto de caracter?sticas morfofuncionais, caracter?sticas morfom?tricas e pontua??o da marcha, atrav?s da an?lise de componentes principais (ACP), e estimar os par?metros gen?ticos, para as caracter?sticas relevantes ap?s an?lise multivariada em cavalos da ra?a Mangalarga Marchador. Dados de 14288 animais, nascidos de 1990 a 2005, foram submetidos ? ACP, objetivando reduzir a dimensionalidade do conjunto de caracter?sticas. Foram consideradas as seguintes caracter?sticas: altura na cernelha, altura na garupa, comprimento da cabe?a, comprimento do pesco?o, comprimento do dorso, comprimento da garupa, comprimento da esp?dua, comprimento do corpo, largura da cabe?a, largura das ancas, per?metro do t?rax, per?metro da canela e a pontua??o da marcha. A partir desta an?lise, sugeriram-se sete vari?veis para descarte, por apresentarem maiores coeficientes de pondera??o, em valor absoluto, a partir do ?ltimo componente principal. Assim, recomendaram-se as seguintes caracter?sticas para serem mantidas em trabalhos que utilizar?o esta mesma base de dados: pontua??o da marcha (PM), altura na garupa (AG), comprimento do dorso (CD), comprimento da garupa (CG), largura da cabe?a (LC) e per?metro da canela (PC). Estas caracter?sticas foram submetidas a uma an?lise gen?tica a fim de estimar suas herdabilidades e correla??es gen?ticas e fenot?picas. Os componentes de (co)vari?ncia necess?rios ? estima??o dos par?metros gen?ticos das caracter?sticas estudadas foram estimados pelo m?todo da M?xima Verossimilhan?a Restrita (REML). O modelo animal multicaracter?stica incluiu efeito gen?tico aditivo direto de animal, como aleat?rio, e os efeitos fixos de grupos contempor?neos, al?m da covari?vel idade do animal ao registro. Altas estimativas de herdabilidade (0,66 para PM a 0,94 para CD) foram encontradas, evidenciando a possibilidade de resposta direta ? sele??o. Foram estimadas correla??es gen?ticas e fenot?picas de ausentes a moderadas magnitudes e discretas tend?ncias gen?ticas ao longo dos anos para maior parte das caracter?sticas avaliadas. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2010. / ABSTRACT This study aimed to evaluate a set of morphofunctional traits, morphometric traits and marcha score data through the principal component analysis (PCA) and genetic parameters for the relevant traits in a multivariate analysis in horses Mangalarga Marchador . Data from 14,288 animals born from 1990 to 2005 were submitted to PCA aimed at reducing the dimensionality of the data set. There had been considered the following characteristics: height at withers, height at croup, lengths of head, neck, back, croup, hip length and body, widths of head, hip width, thorax perimeter, cannon bone circumference and marcha score. From this analysis, it was suggested seven variables to be discarded, because they have higher weightings (eigenvectors) in absolute value from the last major component. Based on the results, there was recommended the following characteristics to be maintained in future work: marcha score, height at croup, length of back, length of croup, width of head and cannon bone circumference. In a second step, these features were subjected to a genetic analysis to estimate their heritability?s and genetic and phenotypic correlations. The components of (co) variance needed to estimate the genetic parameters studied were estimated by Restricted Maximum Likelihood (REML). The trait animal model included direct genetic effect as random and fixed effects of contemporary groups and the covariate age record. High heritability estimates were found, suggesting the possibility of direct response to selection. Genetic and phenotypic correlation were estimate of absence to moderate magnitudes between traits and observed discrete genetic trends over the years for most traits.