Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-13T11:01:33Z No. of bitstreams: 2 catia_borges_ferreira.pdf: 412834 bytes, checksum: 40122e3e956bdcbc843271a59c4c3b02 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-13T11:01:56Z (GMT) No. of bitstreams: 2 catia_borges_ferreira.pdf: 412834 bytes, checksum: 40122e3e956bdcbc843271a59c4c3b02 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-13T11:02:12Z (GMT) No. of bitstreams: 2 catia_borges_ferreira.pdf: 412834 bytes, checksum: 40122e3e956bdcbc843271a59c4c3b02 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Made available in DSpace on 2015-01-13T11:02:12Z (GMT). No. of bitstreams: 2 catia_borges_ferreira.pdf: 412834 bytes, checksum: 40122e3e956bdcbc843271a59c4c3b02 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2013 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Objetivou-se, com este trabalho, avaliar a redu??o dos n?veis de prote?na bruta (PB) e a suplementa??o de amino?cidos industriais para frangos de corte, tipo caipira, a fim de determinar suas exig?ncias para este nutriente. Foram realizados quatro ensaios, abrangendo as fases iniciais (um a 21 dias), crescimento I (22 a 42 dias), crescimento II (43 a 56 dias) e final (57 a 70 dias). Em cada ensaio, 630 machos de linhagem Colonial com idade correspondente ? fase de cria??o foram alojadas nas instala??es experimentais constitu?das por 30 boxes e piquetes. Todos os boxes dispunham de ?rea coberta e ?rea de pastejo. O delineamento utilizado foi inteiramente casualisado, com cinco tratamentos e seis repeti??es de 21 aves cada. Os n?veis de redu??o da PB avaliados foram: 21,5; 21,0; 20,5; 20,0 e 19,5% (fase inicial); 19,0; 18,5; 18,0; 17,5 e 17% (fase crescimento I); 17,5; 17,00; 16,5; 16,0 e 15,5% (fase crescimento II); 17,0; 16,5; 16,0; 15,5 e 15,0% (fase final). Foram avaliadas as caracter?sticas de desempenho (ganho em peso, consumo de ra??o e convers?o alimentar), de carca?a (peso e rendimento de carca?a e de cortes nobres) e de qualidade da carne (cor, luminosidade, capacidade de reten??o de ?gua, perda de peso por cozimento e maciez objetiva). Os n?veis de PB para frangos de corte tipo caipira podem ser reduzidos para 19,5% para a fase inicial e 17% para a fase de crescimento I, desde que seja feita a suplementa??o de amino?cidos. Para as fases crescimento II e final n?o s?o necess?rios mais que 15,5 e 15,0% de PB, respectivamente, por n?o acarretar em baixo desempenho e rendimento de carca?a e cortes, desde que seja atendida a rela??o ideal dos amino?cidos essenciais com a lisina digest?vel. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT The objective of this study was to evaluate the reduction of crude protein (CP) and industrial amino acid supplementation for broilers hillbilly type in order to determine their requirements for this nutrient. Four experiments were conducted, covering the initial stages (one to 21 days), growth I (22 to 42 days), growth II (43 to 56 days) and final (57 to 70 days). In each trial, 630 broilers males Colonial lineage corresponding to the phase were housed in experimental facilities consisted of 30 boxes and paddocks. Each box had a covered area and grazing area. The experimental design was completely randomized with five treatments and six replicates of 21 birds each. The reduction levels of CP were: 21.5, 21.0, 20.5, 20.0 and 19.5% (initial phase), 19.0, 18.5, 18.0, 17.5 and 17% (growth phase I), 17.5, 17.0, 16.5, 16.0 and 15.5% (growth phase II), 17.0, 16.5, 16.0, 15.5 and 15.0% (final phase). We evaluated the performance characteristics (weight gain, feed intake and feed conversion), carcass (weight and carcass yield and prime cuts) and meat quality (color, brightness, water holding capacity, loss of weight cooking and objective tenderness). The CP levels for broilers hillbilly type can be reduced to 19.5% for the initial phase and 17% for stage growth I, provided it is done the amino acid supplementation. For growth II and final phases is not need more than 15.5 and 15.0% CP, respectively, for not result in poor performance and carcass yield and cuts, provided it is done in proper supplementation of essential amino acids relative to lysine.