A study was realized to validate models to predict apparent metabolizable energy (AMEn) of corn used in chickens diets. Data set with informations of experiments published in national literature among 1994 to 2007 was organized. Chemical composition, gross energy and AMEn of 97 corn samples were including in data set. Studies which AMEn was determined by the traditional method of excreta collection with growing chickens were selected. Five models were evaluates, being four recommended for application in corn and one for application in energetic feedstuffs. The models studied were AMEnC1=36.21*CP + 85.37*EE + 37.26*NNE; AMEnC2 =37.5*CP + 85.37*EE + 38.21*NNE; AMEnC3 =4021.8 - 227.5*ASH; AMEnC4 =4337.27 - 57.17*NDF; e AMEnC5 =4371.18 - 26.48*CP + 30.65*EE - 126.93*ASH - 52.26*CF - 25.14*NDF + 24.40*ADF. The values of AMEn obtained for the models were compared with the observed values using regression analysis. In all the evaluated models there is rejection of the nullity hypothesis, showing differences between estimated and calculated AMEn values. Decomposition of mean squared deviation (MSD) has been demonstrated that calculated values from models AMEnC1, AMEnC3 and AMEnC5 showed that its models failed to simulate the magnitude and pattern of fluctuation. On the other hand, the estimates made with models AMEnC2 e AMEnC4 showed predominance of component bias of prediction that indicates the models failed to simulate the variability of the data around the mean. Energy values predicted using differents models were compared with calculated values by regression analysis. In conclusion any of five models studied allow estimating precisely the apparent metabolizable energy of corn to chickens.
apparent metabolizable energy; feedstuffs; nutrition; simulation models
