Estimation of the net energy requirement for maintenance in broilers

Area of Science:

• Animal Nutrition and Metabolism
• Poultry Science
• Energy Balance Studies

Background:

• Accurate determination of energy requirements is crucial for optimizing broiler growth and feed efficiency.
• The net energy for maintenance (NE_m) is a key parameter in formulating diets for broilers.
• Indirect calorimetry (ICM) and comparative slaughter (CSM) are established methods for energy evaluation.

Purpose of the Study:

• To determine the net energy requirement for maintenance (NE_m) in broilers.
• To compare the NE_m values obtained using the indirect calorimetry method (ICM) and the comparative slaughter method (CSM).
• To provide reliable NE_m data for broiler diet formulation.

Main Methods:

• A 2x4 factorial experimental design was used, with evaluation method (ICM or CSM) and feed intake levels (25%, 50%, 75%, 100% of ad libitum) as factors.
• Birds (Arbor Acres male broilers, 15 days old) were subjected to ICM or CSM protocols.
• Metabolizable energy intake (MEI), heat production (HP), and retained energy (RE) were measured; NE_m was calculated using linear and logarithmic regression models.

Main Results:

• No significant differences were found between ICM and CSM for metabolizable energy (ME), net energy (NE), NE:ME ratio, MEI, HP, or RE.
• Feed intake significantly affected MEI, HP, and RE (p<0.01), with no interaction between evaluation method and feed intake.
• NE_m values estimated by linear regression were 386 kJ/kg BW^0.75/d (ICM) and 404 kJ/kg BW^0.75/d (CSM); logarithmic regression yielded 448 kJ/kg BW^0.75/d (ICM) and 462 kJ/kg BW^0.75/d (CSM).

Conclusions:

• The NE_m values determined by both ICM and CSM are comparable and suitable for practical application.
• The study provides essential NE_m data that can be used as a reference for formulating broiler diets.
• These findings contribute to more precise energy calculations in poultry nutrition.