EXIGÊNCIA DE LISINA PARA ALEVINOS DE TAMBATINGA UTILIZANDO DIFERENTES TÉCNICAS DE FORMULAÇÃO DE RAÇÕES.

• Autor(a) principal: SOUSA, Marilene da Costa
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFMA
• Texto Completo: https://tedebc.ufma.br/jspui/handle/tede/tede/2717
• topic: Aminoácido essencial; Desempenho zootécnico; Composição corporal; Nutrição de peixe; Proteína ideal; Essential amino acid; Zootechnical performance; Body composition; Fish nutrition; Ideal protein; Nutrição e Alimentação Animal.

Lysine is an essential amino acid present in high proportion in fish muscle tissue, being one of the most limiting amino acids in fish feed. The objective was to determine the requirement of digestible lysine in diets for tambatinga (Colossoma macropomum x Piaractus brachypomum) fingerlings using different experimental feed formulation techniques. A total of 1,800 fingerlings weighing 0.82 ± 0.39g were used in a 6 x 2 factorial scheme (digestible lysine level x diet formulation technique), in a randomized complete block design, totaling 12 treatments, with two blocks and three replicates of each treatment per block, with 25 fish per experimental unit. The treatments were composed of isoenergetic, isocalcium and isophosphoric diets containing different levels of digestible lysine (1.20, 1.38, 1.56, 1.74, 1.92 and 2.10%) formulated by two different techniques: supplementation of amino acids and dilution of diets. Performance, food efficiency and body composition parameters were evaluated. With the exception of feed consumption, treatments influenced all variables of performance and food efficiency. Elevation of lysine levels linearly increased digestible lysine consumption and increased quadratic weight gain, specific growth rate, improved feed conversion, digestible lysine efficiency for weight gain and deposition of fish body protein up to the levels estimated at 1.80%, 1.83%, 1.81%, 1.50% and 1.82%, respectively. There was interaction between lysine levels and the feed formulation technique only for body fat deposition and nitrogen retention efficiency. Fish fed diets formulated with the dilution technique presented higher weight gain, specific growth rate and body protein deposition. The elevation of digestible lysine levels increased quadratically the body fat deposition and nitrogen retention efficiency in fish fed with rations formulated by the supplementation technique up to the level of 1.70% and 1.80%, respectively. For fish fed with rations formulated by the dilution technique, it was observed that in rations containing 1.56% and 2.10% of digestible lysine presented higher deposition of body fat and worse retention of nitrogen, respectively. The recommendation of digestible lysine level in rations for tambatinga fingerlings that optimizes body weight gain and deposition is 1.80%, corresponding to 1.89% of total lysine, and the dilution technique can be used in formulation of experimental diets to determine the amino acid requirement.