net energy, broiler, feed ingredients


Metabolizable energy (ME) is the main system used globally in poultry industry for feed formulation and for evaluating feed ingredients and mixed feeds (de Boer and Bickel, 1988). ME is considered a reliable index of what is available to the bird for maintenance and production but is not a predictor of how efficiently the bird uses the available energy (MacLeod, 2000). The ME system developed by Hill and Anderson (1958) was reported to provide less variation in energy values for feed and ingredients than the Fraps PE system, but MacLeod (1994, 1997, 1999) suggest that the low variation of ME values is because the ME system ignores the metabolic responses to feed. A dietary net energy (NE) system is needed that is sensitive to daily rapid protein gain plus changing daily energy maintenance needs caused by the accretion of lean mass (Hilton et al, 2019).