Avaliação nutricional e energética do gérmen integral de milho para galinhas de postura

Abstract

The aim of this study was to determine the nutritional value and energy of corn germ (CG) as well as evaluating the effect of its use in feed for laying hens. Two experiments were conducted, one with metabolism and other performance. In the first experiment (metabolism) was determined initially the chemical composition, metabolizable energy and digestibility coefficients of nutrients from the corn germ for laying hens. First, There were determined the chemical composition of corn germ meal and then held a metabolism trial to determine the values of apparent metabolizable energy (AME) and corrected apparent (AMEn) and apparent metabolizable coefficients of dry matter (AMCDM) and gross energy (AMCDGE). The trial lasted eight days (four for adjustment and four for collection of excretes) were used 60 hens, Lohman LSL white with 29 weeks of age. The experiment was a completely randomized design with three treatments and five replicates of four birds. The treatments consisted of one reference and two tests diets with 20% and 30% inclusion of corn germ. The results were submitted to ANOVA and means compared using t test at 5% probability. In the second experiment (Performance) 200 laying hens with at 26 weeks of age were used . The birds were distributed in a completely randomized design with five treatments and five replicates of eight birds each. The treatments consisted of a reference diet (corn, oil and soybean meal based) and four diets with the following levels of inclusion of CG in the diets: 2.0, 4.0, 6.0 and 8.0%. The results were submitted to ANOVA and the means compared in the Dunnett test at 5% probability and regression analysis was used to verify the effect of inclusion of CG on the performance and egg quality. The corn germ showed the following chemical composition: 96.39% dry matter, 49.48% ether extract, 1.87% of ash, 7243 kcal / kg gross energy, 11.48% protein, 0,19% methionine, cystine, 0,21%, 0,48% lysine, 0,40% threonine, 0,72% arginine, 0,35% isoleucine, leucine 0,83%, 0,57% of valine and histidine 0.37%, as fed. The average values of AME, and AMEn AMCDM and AMCDGE of the germ determined were: 4,578 and 4,548 kcal/kg, 4,723 and 4,372 kcal / kg, 64.95 and 61.86% respectively. According to the results obtained in the performance,The levels of the CG didn´t effect on the variables: feed intake, egg production and egg mass. But, the egg weight and feed conversion were affected, but the inclusion of up to 6% did not affect the performance parameters of laying hens. Regarding the regression analysis there was a linear effect for both variables (weight eggs and feed conversion). The parameters studied in relation to eggs (percentage of the shell, albumen and yolk, albumen height, specific gravity and yolk color) were not affected by increasing levels of CG. The inclusion of CG in diets of laying hens in 2% did not influence the production performance and egg quality and that higher levels can increase the weight of the eggs, thus using levels of the 6% can maintain the feed conversion and in some cases may be recommended depending on their market price.