Níveis de lisina, treonina e metionina+cistina digestíveis em rações para suínos machos castrados de alto potencial genético dos 95 aos 125 kg

• Ano de defesa: 2008
• Autor(a) principal: Santos, Fabrício de Almeida
• Orientador(a): Donzele, Juarez Lopes
• Banca de defesa: Kill, João Luis , Abreu, Márvio Lobão Teixeira 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: Aminoácidos; Suínos pesados; Genótipo
• Palavras-chave em Inglês: Amino acids; Heavy swines; Genotype
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL
• Link de acesso: http://locus.ufv.br/handle/123456789/1698

Three experiments were carried out with 224 barrows of high genetic potential for lean deposition, of 95 to 125 kg, to evaluate the levels of digestible lysine, threonine and methionine + cystine, related to performance and carcass characteristics. Animals were distributed in a blocks randomized design, eight repetitions with two animals in each experimental unit. Experimental rations and water were offered ad libitum in all trials during the entire experiment. In experiment I, 80 barrows were used with initial and final weight of 95.55 ± 1.04 and 125.06 ± 2.90kg respectively, and with treatments corresponding of five digestible lysine levels: 0.54; 0.642; 0.744; 0.846 e 0.948%. No effects of digestible lysine levels were observed on animals daily feed intake (DFI). Quadratic effect was observed in digestible lysine levels on average daily gain (ADG), which increased up to the estimated digestible lysine level of 0.803%, and also improve the feed conversion (FC) up to the estimated level of 0.817%. Effects of treatments on daily lysine intake (DLI) was observed, which increased linearly. Treatments had no effect on animals carcass weight (CW). Digestible lysine levels influenced the lean gain (LG) and the daily lean deposition (DLD) linearly, and influenced the back fat thickness (BFT) in P2, decreasing it linearly. Although the DLD increased linearly, the Linear Response Plateau LRP, was the best which adjusted with data, and was estimated in 0.803% of digestible lysine level, were the plateau started. In experiment II, 80 barrows were used with initial and final weight of 95.87 ± 1.26 and 125.26 ± 2.59kg respectively, and with treatments corresponding of five digestible threonine levels (0.470; 0.497; 0.528; 0.557; 0.587%, with digestible threonine: digestible lysine relation, corresponding to 58.0; 61.0; 65.0; 69.0 and 73.0%, respectively). No effect was observed of digestible threonine levels in DFI and ADG. Quadratic effect was observed on threonine levels in FC, which improved until the estimated level of 0.526%. The treatments influenced daily threonine intake DTI, which increased in a linear way. Levels of threonine didn t influenced CW, LG, BFT in P2 and the DLD. In experiment III, 64 barrows were used with initial and final weight of 95.46 ± 1.09 and 125.21 ± 2.49kg respectively, and four treatments corresponding of four methionine + cystine digestible levels (0.427; 0.466; 0.504 e 0.545%, corresponding to digestible methionine + cystine : digestible lysine ratio of 57.0; 62.0; 67.0 and 73.0%, respectively). No effect was observed between digestible methionine + cystine levels and DFI, ADG and FC.Effects of treatments on daily methionine + cystine intake DMC was observed, which increased linearly. Digestible methionine + cystine levels didn t influenced the CW, LG, BFT in P2 and DLD. It is concluded, basing in experiment I, that the digestible lysine levels of 0.803%, corresponding of digestible lysine intake of 24.60 g/day, provide the best results for ADG and DLD, level of 0.817%, corresponding of digestible lysine intake of 25.03 g/day, provide the best results for FC and the level of 0.948%, corresponding of digestible lysine intake of 29.09 g/day, provide the best results for LG and BFT in P2. In experiment II, the digestible threonine level of 0.526%, corresponding of 65% threonine/digestible lysine ratio and daily threonine intake of 18.49 g/day, provide the best results for FC. In experiment III, the digestible methionine + cystine level of 0.427%, corresponding with digestible lysine relation of 57% and a methionine + cystine intake of 14.20 g/day, provide the best results to performance and carcass characteristics.