Proteína bruta em dietas para suínos machos castrados e fêmeas da raça Piau, nas fases inicial, de crescimento e de terminação

• Ano de defesa: 2013
• Autor(a) principal: Sousa Junior, Antonio Alcyone Oliveira de
• Orientador(a): Lopes, Paulo Sávio
• Banca de defesa: Carneiro, Antônio Policarpo Souza , Dutra Junior, Wilson Moreira , Matos, Daniele Silva de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Zootecnia
• Departamento: Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul
• País: BR
• Palavras-chave em Português: Avaliação de alimentos; Nutrição animal; Resíduo de cervejaria; Silagem
• Palavras-chave em Inglês: Food evaluation; Animal nutrition; Brewery waste; Silage
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::GENETICA E MELHORAMENTO DOS ANIMAIS DOMESTICOS
• Link de acesso: http://locus.ufv.br/handle/123456789/1830

The objective of the research was to analyze the crude protein levels in diets for both barrows and gilts of the Brazilian breed Piau, separately, during three phases: starting, growing, and finishing. For each phase of the research, two experiments were conducted, one with a group of barrows and the other with a group of gilts. On each experiment conducted, 24 swine were used. The average initial weight and age were: 15.0±2.6 kg, and 75±7.8 days old; 35.0±4.4 kg and 127±13.2 days old; and 65.0±7.1 kg and 172±17.8 days old, for the starting phase, growing phase and finishing phase, respectively. The animals were allotted to a randomized design with four levels of crude protein and six replicates. The four levels of crude protein feed used were: 10.2%, 12.6%, 15.0% and 17.40%, for the starting phase; 9.6%, 12.0%, 14.4% and 16.8%, for the growing phase; and 9.0%, 10.6%, 12.2% and 13.8%, for the finishing phase. At the end of the finishing phase, the animals were slaughtered at 95±2 kg and we evaluated the liver, visceral fat, hot carcass weight, viscera weight, cold carcass weight, muscle and bone weight, subcutaneous fat (backfat) weight, main carcass cuts weight, perirenal fat and kidneys. We also estimated the hot carcass, offal and carcass yields and measured the loin eye area, carcass length, ham length and backfat thickness. In the starting phase, for the barrows, the crude protein level only influenced the feed conversion, which was quadratically reduced to the minimum of 13.3% crude protein. For gilts, there was no effect of protein levels on the variables studied. In the growing phase, for barrows, there was no influence of the level of dietary crude protein on the variables studied. In gilts, the daily feed intake decreased quadratically to the level of 12.9% crude protein in the ration. This decrease in consumption reduced the intake of energy and amino acids, and this had a direct effect on the daily weight gain of the animals, which was quadratically reduced to the level of 13.3%, indicating a lower protein level for this category. In the finishing phase, the levels of dietary crude protein did not affect the performance variables for barrows. As for gilts, in the finishing phase, statistical differences were observed in the variables daily weight gain, which increased quadratically to the level of 10.4% crude protein, and backfat thickness, which also increased quadratically to the level 11.4% crude protein in the ration; however, the increase in backfat thickness, daily feed intake and feed conversion did not change with varying levels of crude protein. Regarding the variables for slaughter, we observed that, in barrows, the visceral fat had a linear effect, with a reduction to the level of 12.1% crude protein in the ration. The other characteristics were not affected by varying levels of dietary crude protein. We did not find that the varying levels of dietary crude protein influenced the responses to the parameters studied in gilts. Regarding carcass characteristics in barrows, the varying levels of dietary crude protein caused no variation of the responses to the parameters studied. In gilts, statistical differences were found only on the shoulder and ham cuts. On the shoulder, the level of crude protein increased exponentially to 11.4%, while the ham showed linear variation and weight loss with the increased level of dietary crude protein. The other variables studied in the carcass were not affected by varying levels of dietary crude protein. In the starting phase, the dietary crude protein levels are 13.3% for Piau barrows and 10.2% for gilts of the same breed; in the growing phase, the level of crude protein in diets is 9.6% for barrows and gilts; and, in the finishing phase, the level of dietary crude protein is 9.0% for barrows and gilts.