Simple Summary: While regulations and guidelines vary globally and across nations, meat and bone meal (MBM) can be utilized for nutritional purposes for monogastric. Meat and bone meal is commonly included in poultry feed as a source of amino acids, calcium and phosphorus. The optimal inclusion of MBM in poultry diet formulation depends on the accurate estimation of the metabolizable energy content of MBM. The current available apparent metabolizable energy (AME) value of MBM is acquired from reference tables or equations based on assessments conducted with old birds (5 weeks old). This approach overlooks the potential influence of the age of broilers on the digestibility and utilization of energy-derived nutrients, hence AME or nitrogen-corrected AME (AMEn) values of MBM. Therefore, the present study aimed to examine the impact of the age of broilers on the AMEn of MBM from day 1 to 42 of age. The results revealed that the AMEn of MBM increased with the advancing age of broilers. Age-dependent AMEn values of MBM might be adopted in feed formulation for broilers. The influence of broiler age on the apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) of meat and bone meal (MBM) was investigated. A corn–soy basal diet and an experimental diet wherein 300 g/kg of the basal diet was replaced (w/w) with MBM were developed. The diets, in pellet form, were fed to six replicate cages across six age groups, namely d 1 to 7, 8 to 14, 15 to 21, 22 to 28, 29 to 35 or 36 to 42 d post-hatch. Birds were fed either a starter diet from d 1–21 or a finisher diet from d 22–35. Basal and experimental diets were introduced on d 1, 8, 15, 22, 29 and 36 with 10 (d 1–7), 8 (d 8–14) and 6 (d 15–42) birds per replicate. Total collection of excreta was carried out during the last 4 d of each age period. A linear decrease (p < 0.001) in the retention of dry matter and nitrogen was observed with advancing age. The AMEn of MBM showed a linear increase (p < 0.05), rising from 12.56 MJ/kg during d 1–7 to 13.90 MJ/kg during d 29–35, followed by a decline to 13.41 MJ/kg during d 36–42. The current findings showed that the energy utilization of MBM increased with the advancing age of broilers. Age-dependent AMEn values of MBM may need to be considered when MBM is included in feed formulations. [ABSTRACT FROM AUTHOR]