A feed is designed by a team of specialists (engineers and veterinary surgeons) with a high level of scientific and technical expertise who choose a selection of raw materials (selected on the basis of origin, along with nutritional and organoleptic quality) with a nutrient content which perfectly fulfils the requirements of the animals for which the feed is intended.

A feed consists of : 
=> water
=> dry matter:
      - organic matter (fat, carbohydrates, protein)
      - mineral matter (macro-elements (minerals) and trace elements)
      - vitamins

This corresponds to the ingredients of a feed after it has been totally dehydrated, in contrast with the crude matter which is the fresh feed.
A source of fibre (cf. cellulose), it is essential for healthy intestinal transit and psychological wellbeing. In the wild or at grass, horses will graze for 16 hours a day. It is therefore important to provide for your horse’s dry matter needs so as to avoid any feeling of hunger, to keep him occupied and to encourage normal tooth wear : 
=> 1 kg of hay = 40 minutes occupation feeding time
=> 1 kg of concentrate = 10 minutes occupation feeding time

A component of plants, this is one of the main sources of fibre. It helps regulate intestinal transit.
The horse’s daily requirements in terms of long fibre are estimated at between 15 and 18 % of the total feed ration. It is essential to be aware of fibre quality :
- Good quality : forage that has been properly harvested and stored (true cellulose)
- Lower quality : straw (primarily consisting of lignin), slightly digestible cellulose.

This is the horse’s source of fuel, and is measured in equine forage units (1 EFU = 1 kg of barley) (3200 kilocalories of raw energy). The INRA [French National Institute for Agronomic Research] provides tables defining the EFU equivalent of raw materials to help calculate feed rations.

These are molecules made up of amino acids which are able to cover the major functions throughout the horse’s life (growth, muscle development, reproduction, exertion).
10 amino acids are described as “essential” (E.A.A.) (lysine, methionine, cystine, threonine, etc.): the horse’s body is unable to completely provide for its E.A.A. requirements. It is therefore essential to provide your horse with a balanced diet containing amino acids so as to prevent any deficiencies or damage to vital functions.
The protein content of a feed is evaluated by means of 2 units: 
=> EDNM (Equine Digestible Nitrogen Matter), developed by the INRA in 1984
=> TNM (Total Nitrogen Matter), but which is not as accurate as EDNM since it does not take protein origin and digestibility into account.
Unlike other species, horses have fairly low protein requirements (500 to 700 g maximum per day).