This study was conducted to develop equations to predict the digestible (DE) and metabolizable energy (ME) for growing pigs by using the chemical compositions of five corn, two wheat and six rice samples. A total of 13 castrated boars were chosen and fed 13 diets formulated with different cereal feed ingredients according to a 13 × 6 Youden square design. The DE and ME contents, the ratio of ME to DE, and the nutrient digestibility among the 13 cereal feed ingredients were different (p < 0.05), and the DE and ME ranged from 13.77 MJ/kg to 17.05 MJ/kg and 13.40 MJ/kg to 16.73 MJ/kg, respectively. The DE and ME were negatively correlated to the NDF (p < 0.10) and ADF (p < 0.05) contents among the test cereals; however, the DE and ME contents were positively correlated with the starch content. Based on the chemical analysis, the models for predicting the DE and ME in the cereal feed ingredients were DE (MJ/kg) = 0.1364 × Starch (%) - 0.2352 × ADF (%) + 11.4467 and ME (MJ/kg) = 0.9838 × DE (MJ/kg) - 0.0165 × CP (%) + 0.0538. In conclusion, the different chemical compositions of different cereal feed ingredients led to large variations in the energy concentration and digestibility of nutrients for growing pigs. The number of cereal samples needs to be further increased to improve the accuracy of the equations for predicting energy contents.
Keywords: available energy; cereals; growing pigs; nutrient digestibility; prediction equations.