Principal components analysis of morphological and functional traits, curve and allometric growth in cattle Guzera evidence of weight gain on pasture

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-12-17T17:32:13Z No. of bitstreams: 2 ricardo_costa_sousa.pdf: 978334 bytes, checksum: 95ce2c281d2839fc0eb4f11a7f66ac37 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-12-17T17:32:39Z (GMT) No. of bitstreams: 2 ricardo_costa_sousa.pdf: 978334 bytes, checksum: 95ce2c281d2839fc0eb4f11a7f66ac37 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2015-12-17T17:32:39Z (GMT). No. of bitstreams: 2 ricardo_costa_sousa.pdf: 978334 bytes, checksum: 95ce2c281d2839fc0eb4f11a7f66ac37 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2011Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG)Foi desenvolvida uma Prova de Ganho em Peso (PGP) a pasto com animais da ra?a Guzer? na fazenda Meleiro no munic?pio Curvelo ? MG, oficializada pela Associa??o Brasileira dos Criadores de Zebu (ABCZ). Foram avaliados 45 machos da ra?a Guzer? rec?m-desmamados, com peso e idade iniciais m?dios e desvio padr?o de 219,9 ? 38,05 kg e 325,8 ? 28,0 dias, respectivamente. Na prova os animais consumiram pastagens de Brachiaria brizantha e suplementa??o m?ltipla, receberam tratamento sanit?rio e foram mantidos em condi??es uniformes de manejo por um per?odo de 294 dias. As avalia??es aconteceram a cada 56 dias. A partir desta PGP buscou-se avaliar uma fun??o n?o-linear que melhor descrevesse a curva de crescimento dos animais, estimar o desenvolvimento relativo da ?rea de olho de lombo, medida por ultrassonografia, da circunfer?ncia escrotal e de medidas morfom?tricas em rela??o ao peso vivo de bovinos da ra?a Guzer? atrav?s do estudo do crescimento alom?trico; avaliou-se tamb?m um conjunto de caracter?sticas, por meio de an?lise de componentes principais, visando identificar as caracter?sticas que representam a maior parte da varia??o fenot?pica. As caracter?sticas avaliadas por componentes principais foram: peso aos 205 dias (P205), peso aos 365 dias (P365), peso aos 550 dias (P55), ganho m?dio di?rio (GMD), circunfer?ncia escrotal (CE), altura na garupa (HG), comprimento corporal (CC), circunfer?ncia tor?cica (CT), ?rea de olho de lombo (AOL), estrutura (E), precocidade (P) e musculosidade (M). No presente estudo, a fun??o de Von Bertalanffy foi a que melhor se ajustou para descrever o crescimento dos machos da ra?a Guzer? na PGP a pasto, j? o crescimento alom?trico apresentou-se heterog?nico negativo para todas as caracter?sticas avaliadas em rela??o ao peso vivo. Quanto a an?lise de componentes principais os tr?s primeiros componentes principais explicaram 74,51% da varia??o total dos dados, sendo estes associados aos maiores autovalores e retendo assim, maior vari?ncia dos dados. As caracter?sticas que tiveram maior participa??o nestes componentes foram P205, P e M.Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2011.ABSTRACT It was developed in a performance test (PGP) to grazing animals on the farm Guzera Meleiro Curvelo the municipality - MG, officiated by the Brazilian Association of Zebu Breeders (ABCZ). We evaluated 45 male weanling Guzer?, with initial average weight and age and standard deviation of 219.9 ? 38.05 kg and 325.8 ? 28.0 days, respectively. At trial, the animals were grazing Brachiaria brizantha and supplementation multiple received sanitary treatment and were maintained under uniform management for a period of 294 days. The evaluations took place every 56 days. From this PGP sought to evaluate a nonlinear function that best describe the growth curve of animals, estimate the relative development of the loin eye area measured by ultrasound, scrotal circumference and morphometric measurements in relation to body weight bovine Guzera through the study of allometric growth, was also evaluated a set of features through principal component analysis, to identify the characteristics that represent most of the phenotypic variation. The characteristics evaluated by principal components were: weight at 205 days (P205), weight at 365 days (P365), weight at 550 days (P550), average weight gain (ADG), scrotal circumference (SC), hip height (HG), body length (CC), thoracic circumference (TC), loin eye area (LEA), structure (E), precocity (P) and muscle (M). In this study, the Von Bertalanffy function was the best fit to describe the growth of males Guzera grazing on PGP, as the allometric growth presented heterogonic negative for all traits in relation to body weight. In this study, the Von Bertalanffy function was the best fit to describe the growth of males Guzera grazing on PGP, as the allometric growth presented heterogonic negative for all traits in relation to body weight. As for principal components analysis the first three principal components explained 74.51% of the total variation of data, which are associated with larger eigenvalues and thus retaining, greater data variance. The characters with the highest participation in these components were P205, P and M