Avaliação nutricional de grãos secos de destilaria contendo solúveis (DDGS) para frangos de crescimento lento

Abstract

Two experiments were conducted to evaluate the effect of dried distillers grains with solubles (DDGS) from corn as a substitute for soybean meal in the diet of slow-growing broiler chickens from 1 to 56 days of age, and the chemical composition and metabolizable energy (AME) and apparent metabolizable energy corrected for nitrogen balance (AMEn) values of the DDGS. In the first experiment, 480 slow-growing Label Rouge chicks, male and female, were distributed in a completely randomized design with four treatments, six replicates, and 20 birds/replicate. The treatments consisted of DDGS replacement levels with soybean meal at 0, 15, 30, and 45%, corresponding to 0, 4.9, 9.90, and 14.7% DDGS in the starter diets; 0, 4.3, 8.6, and 13.0% DDGS in the grower diets and 0, 3.9, 7.9, and 11.8% DDGS in the finisher diets. The parameters evaluated were: weight gain, feed intake, feed conversion ratio, and viability at 21, 42, and 56 days. At 56 days of age, 24 birds, one per replicate, were slaughtered to obtain carcass yield, commercial cut yield, and abdominal fat determination. Blood was collected from the same number of birds for serum dosages of total protein, albumin, glucose, total cholesterol, HDL, LDL, and VLDL. In the second experiment, a metabolic assay was conducted using the total collection method. 180 slow-growing Label Rouge broiler chicks, 13 days old, were housed in metabolic cages. The birds were distributed in a completely randomized design, consisting of two treatments, with six replicates, 10 birds per experimental unit, and a reference diet. The treatments consisted of the reference diet + DDGS and the reference diet + DDGZ + enzyme complex. For the composition of the test diets, DDGS replaced 30% of the reference diet, with and without the addition of the enzyme complex. The enzyme complex consisted of the enzymes: xylanase, beta-glucanase, and xyloglucanase and was added at 0.002 mg/kg. At the end of the experiment, the amount of feed consumed per experimental unit and the total amount of excreta produced were determined. From the results of the laboratory analyses, AME, AMEn, CMEMA, CMMS, CMPB, and CMMFDN were calculated. The data were subjected to analysis of variance using the F-test at 5% significance using the R Studio software. At 21 days, significant differences (p<0.05) were observed in feed conversion, which was better for chickens fed diets containing 15 and 30% DDGS replacing soybean, compared to the treatment without DDGS. Chickens fed DDGS showed higher blood concentrations of triglycerides and VLDL compared to birds that did not receive DDGS in their diet. There was no significant effect of the use of an enzyme complex on the AME and AMEn values of DDGS. The AME values obtained were: 3,735.5 and 3,703.9 kcal/kg and the AMEn values were 2,875.4 and 2,746.6, respectively, for the diets with DDGS and DDGS + enzyme complex. The values for CME, CMMS, CMPB, and CMFDN for DDGS were 87.85%, 78.77%, 71.18%, and 35.36%, respectively, as well as for DDGS with added enzyme, which were 87.60%, 77.04%, 69.37%, and 34.86%, respectively. The use of DDGS is recommended at levels up to 30% as a replacement for soybean meal, corresponding to 9.90% in the diet of slow-growing broilers up to 21 days of age, and up to 45%, corresponding to 13.0% and 11.8% in the diet for the growing and finishing phases, respectively. DDGS in the diet of slow-growing broilers at 21 days of age did not affect the metabolizability coefficients. The addition of an enzyme complex associated with DDGS did not affect the metabolizability coefficients of the nutrients.