Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-11-18T13:31:11Z No. of bitstreams: 2 igor_nero_kelles_lage.pdf: 553484 bytes, checksum: f586c23a68b5565ba2fdb50202e3ac93 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-11-18T13:31:37Z (GMT) No. of bitstreams: 2 igor_nero_kelles_lage.pdf: 553484 bytes, checksum: f586c23a68b5565ba2fdb50202e3ac93 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2015-11-18T13:31:37Z (GMT). No. of bitstreams: 2 igor_nero_kelles_lage.pdf: 553484 bytes, checksum: f586c23a68b5565ba2fdb50202e3ac93 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2010 / Objetivou-se com este trabalho avaliar quanto ? classe sexual de bovinos influencia as caracter?sticas de desempenho, consumo, efici?ncia alimentar, al?m das caracter?sticas de carca?a e qualidade de carne. O experimento foi realizado em delineamento inteiramente casualizado, utilizando-se 15 bovinos, sendo 5 machos castrados, 5 f?meas castradas e 5 f?meas. Os animais foram distribu?dos aleatoriamente em baias individuais, onde receberam a mesma dieta por um per?odo de 106 dias. Ao final do experimento, foram abatidos e coletados os dados referentes ?s caracter?sticas de carca?a: pH, temperatura, peso das carca?as quentes e frias, ?rg?os e v?sceras. Da meia carca?a direita foram pesados os cortes: ac?m, paleta, ponta de agulha, cox?o e alcatra completa. Na meia carca?a esquerda, foram mensuradas a ?rea de olho de lombo, a espessura de gordura subcut?nea e o comprimento da carca?a. A sec??o HH foi retirada de cada animal, entre a 9? e a 11? costela; e dela foram separados e pesados os m?sculos, gordura e ossos. Foi coletada uma amostra do m?sculo Longissimus dorsi, correspondente a cada animal para an?lises de composi??o qu?mica, ?ndice de fragmenta??o miofibrilar, for?a de cisalhamento, porcentagem de col?geno sol?vel e teor de col?geno total, colora??o e c?lculo das perdas. Entre as classes sexuais n?o houve diferen?a estat?stica para ganho de peso, consumo e digestibilidade da mat?ria seca e dos nutrientes, efici?ncia alimentar e caracter?sticas de carca?a. Avaliando-se o m?sculo Longissimus dorsi dos bovinos pertencentes ?s diferentes classes sexuais, verificou-se tamb?m que n?o houve diferen?a estat?stica para as vari?veis: maciez, cor, pH, percentual de col?geno sol?vel e quantidade total de col?geno, perdas e composi??o qu?mica. De acordo com as caracter?sticas de carca?a, desempenho, consumo, efici?ncia alimentar e das caracter?sticas qualitativas da carne avaliadas, verifica-se que n?o h? necessidade de castra??o de f?meas e machos bovinos com o intuito de aumentar o desempenho, melhorar as caracter?sticas de carca?a e qualidade de carne. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2010. / ABSTRACT The goal of this work was to evaluate how cattle gender profile influences performance, intake, feed efficiency, as long as carcass and traits beef quality. The experiment was carried out in a complete randomized design, using 15 animals (5 steers, 5 spayed heifers and 5 intact heifers.) They animals were distributed randomly in individual pens. All animals receive the same diet for a period of 106 days. At the end of the experiment, they were slaughtered and data related to the carcass were collected: pH, temperature, of hot and cold carcass weight, organs and visceral weight. The right half carcass was processed into chuck, shoulder, flank boneless, round, and d-rump. From de left half carcass was taken of measure of the rib eye area, fat thickness and carcass length. From the 9th to 11th left half carcass, the rib was cut off (HH section) and then dissected into muscle, fat and bones. A sample of the Longissimus dorsi muscle from each carcass was collected and analyze for it?s chemical composition, myofibrillar fragmentation index, shear force, percentage of total and soluble collagen, color, and losses. Among the sexual classes there wasn?t any difference on performance, intake and digestibility of dry matter and nutrients, feed efficiency or carcass characteristics. Evaluating the Longissimus dorsi muscles of the cattle from different sexual classes it was verified that there wasn?t any difference for the variables: MFI, Shear force, color, pH, percentage of total and soluble collagen, loss and chemical composition. From the data of carcass traits, performance, intake, feed efficiency and meat quality evaluated it can be concluded that there isn?t necessary to castrate heifers and steers in order to increase performance and improve carcass traits and meat quality.