Estimating maintenance energy requirements of Borgou cattle to improve feeding precision under tropical conditions

Introduction Improving the energetic efficiency of cattle under tropical conditions is essential to enhance productivity while limiting feed costs and greenhouse gas emissions. The indigenous Borgou breed plays a central role in West African beef systems, yet its maintenance energy requirements remain insufficiently quantified under controlled feeding conditions. This study estimated the energy needed for maintenance in growing Borgou bulls, including net energy for maintenance (NEm, the energy required to sustain basic body functions), metabolizable energy for maintenance (MEm, the dietary energy needed to meet maintenance), and the efficiency of metabolizable energy use for maintenance (km). Methods Nine Borgou bulls were assigned to three metabolizable energy supply levels relative to maintenance: 1.0 × M, 1.25 × M, and 1.5 × M, corresponding to maintenance, 25% above maintenance, and 50% above maintenance, respectively, in a 3 × 3 Latin square design. Respiratory gases were measured using the GreenFeed system, and heat production (HP) was calculated according to Brouwer’s equation. To improve the relationship between heat production (HP) and metabolizable energy intake (MEI), HP was log-transformed before regression analysis. Results and discussion Feeding level significantly increased O₂ consumption, CO₂ and CH₄ production, urinary nitrogen excretion, and HP, confirming a clear metabolic response to energy supply. The log-linear model was significant: ln(HP) = −1.2046 + 0.9959 × MEI, with R² = 0.636 and P < 0.001. The estimated NEm was 0.300 MJ/kg BW⁰·⁷⁵/day, while MEm was 0.487 MJ/kg BW⁰·⁷⁵/day, with a corresponding km of 0.616. These values provide locally relevant reference coefficients for formulating more precise rations for Borgou cattle. In practical terms, they can help farmers and advisors better match feed supply to animal requirements, reduce unnecessary feed costs, and improve feeding efficiency in tropical beef production systems.