Exigência de lisina digestível para poedeiras semipesadas

Abstract

Two experiments were carried with the aiming at determining the nutritional requirement of digestible lysine for brow-egg laying hens. The first experiment was performed at the end of the first production cycle, in the period from 50 a 66 weeks of age and the second with birds in the period from 74 to 90 weeks of age. In both experiments, 150 layers Shaver Brow laying hens, distributed in a completely randomized design, with five treatments (digestible lysine levels: 0.79, 0.82, 0.85, 0.8 and 0.91%), six replications and five birds for experimental unit. The experimental period lasted 16 weeks and it was divided in four periods of collection of the eggs, being each one corresponding to 28 days. The parameters evaluates were the productive performance (production, mass and egg´ weight), of the intake consumption (feed and lysine), of the feed conversion (mass and egg dozen), egg components (albumen, yolk and shell), of the egg quality (albumen and yolk index, Haugh units and egg shell specific quality). In the first experiment, the productive performance, the feed intake, the feeds conversions, the components percentage, egg quality and yolk index were not influenced (P>0.05) by the levels of digestible lysine, except for the lysine intake which show a linear response (P<0.05) with increase in the digestible lysine levels. For the albumen index and Haugh units, the LRP model (Linear Response Plateau) adjusted better to the data, estimating at 0.832% and 0.883 % of the lysine digestible, respectively. In the second experiment, was observed a linear increase (P<0.05) of lysine intake increased as the level of dietary lysine and quadratic effect (P<0.05) of the yolk percentages, estimating the level of 0,837% digestible lysine for the lowest percentage of yolk. Variables such as performance, consumption, feed conversion, components percents and egg quality had not shown significant differences (P>0.05). Based on productive parameters that were not influenced by levels of lysine diets in both experiments, suggested the level of 0.79% of lysine, for brow-egg laying hens in the period from 50 to 66 weeks and 74 to 90 weeks of age