Revista Colombiana de Ciencias Pecuarias
versão impressa ISSN 0120-0690
POSADA, Sandra L et al. Energy requirements for beef cattle: concepts and experimental results in tropical conditions. Rev Colom Cienc Pecua [online]. 2011, vol.24, n.4, pp. 617-622. ISSN 0120-0690.
Life, interpreted as a combustion process, has been the basic principle guiding the study of energy metabolism, whether from calorimetric or slaughtering techniques. The relationships between metabolizable energy intake, retained energy, and heat production -together with the separation of maintenance and production functions- are the basis for the discussion of the factors affecting energy requirements and utilization efficiency in beef cattle. Energy metabolism is influenced by factors intrinsic and extrinsic to the animal, including age, weight, breed, body composition, sexual condition, production potential, environmental conditions, activity and feeding level, whose effects are discussed in this review. The understanding of these factors represents an opportunity to direct research programs seeking to determine the energy requirements under tropical conditions, in a similar way to the research conducted in developed countries.
Palavras-chave : efficiency; energy requirements; maintenance; production; zebu cattle.