Níveis de energia metabolizável e lisina digestível para codornas japonesas em fase inicial de postura criadas em estresse térmico

Abstract

The production environment of the Japanese species can have negative effects, since the bird in thermal risk by heat can reduce the feed take. This causes less circulation of nutrients in the bloodstream to maintain its basal metabolism and, consequently, egg production decreases. Thus, a balanced balancing in the formulation of diets should be made taking into account the environmental temperature and its effects on the physiology, the behavior of the animals and the cost of production. Nutrition corresponds to the majority of production costs, with protein fraction and diet energy being the components that contribute most to diet costs. Energy is the starting point for formulation howerer is not classified as a nutrient but as a major component of oxidation during metabolism. Metabolizable energy is a form expressed nutritional requeriments in birds and is the factor that determines the performance of quails, the consumption of feed is regulated by the energetic measure. Therefore, it is necessary the specific knowledge of the energy of each ingredient to make available the balances of the diets. Currently, knowledge about protein metabolism and the emergence of new industrial amino acids possesses possibilities for the most recent dietary protein nutrients of bird nutritional care applying the ideal protein concept. Lysine is an essential amino acid and the second limiting amino acid in poultry diets and interest in amino acid studies in poultry feed is critical to the fact that lysine has a low supplementation cost and can improve quail performance. The aim of this study was to carry out a review of the literature in order to recapitulate information on the production environment and nutrition of Japanese quails, and showing the nutritional importance of metabolizable energy and lysine digestible aiming the maximum production thereof. In Chapter II, a scientific paper entitled "Levels of metabolizable energy and digestible lysine for early-stage Japanese quails produced under thermal stress" was prepared. The purpose of this study was to evaluate the effects of dietary MS and DL levels in the diet on the zootechnical performance, physical-chemical quality eggs and economic results of Japanese quails in the initial production stage created in a thermal stress. 780 Japanese quails, 63 days with 149 g ± 0,010 by were usedin a randomized design experimente with with 12 treatments in a 3 × 4 factorial design (MS levels: 2,600, 2,875 and 3,150 kcal ME / kg of diet and DL levels: 0.90, 1.05, 1.20, 1.35%), with five replicates and thirteen birds per experimental unit, with an experimental period of four cycles of 28 days. There was an interaction between ME and DL only for energy conversion per gram of egg. Increasing dietary DL levels had linear on digestible lysine intake, correct metabolizable energy intake, net energy intake and caloric increment. The other variables of performance and egg quality as egg weight, specific gravity, thickness and shell weight index were higler with dietary levels of 2,875 and 3,150 kcal ME/kg compared to 2,600 kcal/kg. It is concluded that the level of 3,150 kcal / kg of ME in the diet is the most indicated for maximum egg production and mass and when associated with the level of 0.90% of DL, it promotes a better energy conversion efficiency per gram of egg for Japanese quails in the initial stage of thermal stress posture.