ENERGY

The energising components of horse feed is vital for the bodily functions of the horse. Both the musculoskeletal system and the body’s internal processes require energy as ‘fuel’.

The ability of horse owners to adapt feed rations according to the needs of the horse is crucial for its performance and well-being. Let us talk about some important aspects that affect the energy needs of a horse.

Sources of energy
Fibrous energy: The primary source of energy in the diet of a horse consists of forage (i.e. grass, hay, silage, straw, etc.). The energy in the forage feed is absorbed in the large intestine of the horse by way of a microbial fermentation of cellulose. Carbohydrates: Starches and sugars – occurs naturally in hay but also added in the form of for example molasses and cereals. Fat: Found in, for example, oats and also added in the form of vegetable oils.

Increased energy requirements
Intensified exercise and training will always lead to an increased demand for energy. Most horse owners are aware of this and learn how to adapt the supply of energy to the energy needs of their horse. There are also other

– although often overlooked – situations when there is an equally high demand for energy. Cold weather conditions, for example, will always lead to an often underestimated ‘upshift’ in the horse’s need for energy. Many horse owners fail to understand the chill factor of wind and rain combined which can only be counterbalanced by an increased intake of energy. Failing to increase the intake of energy will lead to the horse breaking down stored energy supplies, i.e. fat, in order to produce heat. As a consequence, the horse starts to lose its heat insulating layer of fat which, if the cold weather conditions continue, creates a vicious circle. Other energy-consuming processes include gestation, lactation and growth. The energy needed in the final phase of gestation and the significantly increased demand for energy during lactation are often underestimated. The energy need of a lactating mares is considerably higher than that of a non-lactating mare. The need for extra energy is especially great during the first three months after foaling. It is estimated that a mare’s need for energy doubles during lactation compared to in her first few months of gestation (first trimester of gestation).

Different energy concepts
In Sweden, energy is measured in MJ (megajoules). We will talk about how different countries measure energy later on. First, let us look a little closer at different ways of defining energy. Gross energy – the total amount of energy in the feed consumed. Digestible energy (DE) – the gross energy of the feed minus the energy content of the faeces. Metabolisable energy (ME) – the digestible energy minus energy excreted in urine and as combustible gases. Net energy (NE) – the metabolisable energy minus the energy used when eating and digesting food. In Sweden, the energy content of a feed is measured in MJ metabolisable energy (ME). Denmark and Norway on the other hand measure energy need and food content in NE (net energy) and FU (food units) while in France, the food content is measured as net energy (NE). In Germany, the United Kingdom and the US, the definition of digestible energy (DE) is used. In the US and certain other countries, the definition of Mcal (megacalories) is also used to measure energy. Sometimes the energy content of a feed is specified as energy per kilogram of feed or per kilogram of dry matter. The above shows the importance of horse owners who chose to import their horse feed from abroad to be attentive to the way in which the content of energy is declared. Crude protein is usually not declared as digestible energy (DE) but as crude protein in %.