Metabolisable energy

Metabolisable energy is abbreviated to ME. It is stated in the unit megajoules per kilogram (MJ/kg) and is calculated according to GfE 2014.

In principle, horses do not have the total gross energy of a feed available to them. Part of the energy is excreted in the faeces or lost through intestinal gases or urinary substances such as hippuric acid. So if you want to know the proportion of feed energy that the horse can actually use for performance, you need to use the figure for metabolizable energy (ME).

Until 2014, energy in horse feeding was expressed in Digestible Energy (DE), i.e. “digestible energy”. Here, only losses via the faeces are taken into account. The figure in ME is therefore more precise and has been the standard for declaration since 2014.

Naturally, a horse’s requirement is also no longer calculated in DE today, but in ME as well. Whereas the maintenance energy requirement (MER) of a warmblood used to be set at 73 MJ DE, the MER is now calculated at around 63 MJ ME.

At first, it may seem confusing that the same feed (e.g. marstall Haferfrei) used to be declared at 12.5 MJ DE and today is declared at “only” 11 MJ ME. However, the horse now also only has “only” 63 MJ ME to cover, instead of 73 MJ DE.