Relações de treonina e triptofano com a lisina digestível em rações para alevinos de tilápia do Nilo

• Autor(a) principal: Takishita, Sylvia Sanae
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1875
• topic: Tilápia (Peixe) - Nutrição - Necessidades; Aminoácidos na nutrição animal; Tilápia (Peixe) - Registros de desempenho; Tilápia (Peixe) - Registros de desempenho; Tilápia (Peixe) - Carcaças; Peixe - Criação; Aquicultura; Tilapia (Fish) - Nutrition - Requirements; Amino acids in animal nutrition; Tilapia (Fish) - Records of performance; Tilapia (Fish) - Records of performance; Tilapia (Fish) - Carcasses; Fish - Creation; Aquaculture; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL::EXIGENCIAS NUTRICIONAIS DOS ANIMAIS

Two experiments were carried to determine the ideal ratio of digestible threonine (Experiment I) and tryptophan (Experiment II):lysine in diets for Nile tilapia (Oreochromis niloticus) fingerlings, Thailand strain. The experiments were conducted at the Laboratory of Fish Nutrition, Department of Animal Science, Federal University of Viçosa. The fish were maintained in aquariums of 130 liters arranged in water recirculation system, controlled temperature and individual aeration and they were fed ad libitum six daily in experimental period of 30 days in each experiment. In the experiment I aimed to evaluate the ideal ratio of digestible threonine:lysine in diets containing suboptimal level of 1.53% digestible lysine. Were used 420 fingerlings with a initial weight of 0.95 ± 0.01 g, distributed in a completely randomized experimental design. The treatments consisted of five diets with different ratios of digestible threonine:lysine (70, 77, 84, 91 and 98%), maintained with equal content of energy. In the experiment II aimed to evaluate the ideal ratio of digestible tryptophan:lysine in diets containing suboptimal level of 1.53% digestible lysine. Were used 360 fingerlings with a initial weight of 1.16 ± 0.19 g, distributed in a completely randomized block design. The treatments consisted of five diets with different ratios of digestible tryptophan:lysine (19.5, 21, 22.5, 24 and 25.5%), maintained with equal content of energy. In both experiments were evaluated the performance parameters and feed efficiency, body composition, rate daily deposition protein and fat and nitrogen retention efficiency. In the experiment I there was quadratic effect of digestible threonine:lysine ratio on feed intake, weight gain, feed conversion, specific growth rate and nitrogen retention efficiency. For feed conversion 1.358% was obtained as optimal level, which corresponded to the ideal ratio of digestible threonine:lysine of 88%. In the experiment II no effect was observed of ratios digestible tryptophan:lysine on performance parameters and feed efficiency, body composition, rates daily deposition protein and fat, and nitrogen retention efficiency. The ideal ratio of digestible threonine: lysine and digestible tryptophan:lysine recommended in diets for Nile tilapia fingerlings are 88% and 19.5%, respectively.