Metabolizable and Net Energy Values of Corn from Various Regions and Prediction Equation Development for Arbor Acres...

This study aimed to determine the apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and net energy (NE) values of corn for Arbor Acres (AA) broilers aged 12-14 and 26-28 days and to develop prediction equations. Ten corn samples with varying chemical compositions were selected. Test diets were formulated using the substitution method, in which corn replaced 40% of the energy-supplying components in a basal diet. A total of 396 male AA broilers at 9 days of age and another 396 at 23 days of age were used across the two metabolism trials. AME, AMEn and NE were determined using the substitution method combined with respiratory calorimetry. Correlations between energy values and chemical components were analyzed. Multiple linear stepwise regression in SPSS was used to establish prediction equations for AME, AMEn, and NE. The results showed that for 12-14-day-old broilers, AME, AMEn, and NE ranged from 13.84-15.66 MJ/kg, 13.39-15.35 MJ/kg, and 8.61-12.56 MJ/kg, respectively. For 26-28-day-old broilers, the corresponding values ranged from 14.62-16.30 MJ/kg, 14.42-16.05 MJ/kg, and 10.42-13.06 MJ/kg. Notably, NE values and AME/GE (gross energy) ratios were significantly higher in 26-28-day-old broilers than in 12-14-day-old broilers (p < 0.05), which increased by 9.33% and 3.96%, respectively. Correlation analysis showed that phytic acid (PA) was significantly negatively correlated with AME, AMEn, NE, AME/GE, and AMEn/GE in the younger group, whereas ash content was significantly negatively correlated with AME and AMEn in the older group. The prediction equations exhibited good fit, with the coefficient of determination (R²) of the best equation reached 0.97. These findings support the precise application of corn in feed formulation and provide a scientific basis for its efficient utilization in poultry production.