Energia metabolizável de alguns alimentos energéticos para frangos de corte, determinada por ensaios metabólicos e por equações de predição

Abstract

Two metabolism assays were carried out with chicks in growth (traditional method of total collection of excreta) in the Animal Science Department of UFLA, Lavras - MG, to determinate of the nitrogen-corrected Apparent Metabolizable Energy (AMEn) of some feedstuffs, as well as the determination of the energy values by prediction equations presented in the national and international literature. In the assay I, it was determined AMEn of some energy alternative feedstuffs to the corn (corn germ, corn quirera, ground and grain millet and ground and grain sorghum) and, in the second, AMEn of the seven corn hybrids. At same time to the experiments, it were realized laboratory analyses for determination centesimal composition of the tested feedstuffs. The food composition it was used in the prediction AMEn by equations. The calculated values were, then, compared with observed, using the Spearman correlation and SCOTT-KNOTT test. In addition, confidence intervals were obtained by the metabolic assays. Ground millet AMEn was similar to AMEn grain millet (3223 and 3279 kcal/kg DM respectively), being the same observed for the sorghum (3529 and 3573 kcal/kg DM, ground and grain, respectively). The AMEn for the corn germ was 3503 kcal/kg DM, while, for the corn quirera, it was 3351 kcal/kg DM. The corn hybrids energy values varied from 3665 to 3804 kcal/kg DM. Among the studied equations, the 4021.8 - 227.55ash equation only correlated (P<0,01) with AMEn mean value observed in vivo, estimating the largest number of energy values inside of calculated confidence intervals. The other equations were not correlated (P<0,01) with the AMEn values. The results obtained in this assays, allow concluded that the 4021.8 - 227.55ash equation should be used to predict EMAn values of the studied feedstuffs.