The horse feeding diet should always be based on the nutritional content of the forage. After that, you can add the necessary supplements in the form of hard feed (cubes, oats, etc) and minerals and vitamins.
Under feeding is Common Horse Feeding Mistakes. Under feeding can be a problem with senior horses and horses that are working hard. However, keep in mind that the bulk of your horse’s diet should be made up of grass or hay. Under feeding hay or pasture, and over feeding grains and concentrates can lead to colic
Horses have evolved to eat food that takes time to collect, chew and swallow. The stomach in a mature horse makes up less than 10% of the volume of the digestive canal; the hindgut, on the other hand, makes up 80%. The horse has a relatively short small intestine – foregut – but has an appendix which is one metre long and can hold 25–35 litres. The hindgut can hold 3 times as much as the foregut and is 3–4 metres long. The digestive canal makes up about 15% of the horse’s weight. Since the horse’s stomach is relatively small, the food passes out of it very quickly. Unlike humans, the horse has not developed any stretch receptors in its stomach which signal when the walls of the stomach are distended, i.e. that it is full. The horse simply does not feel when its stomach is full, and can therefore easily eat too much if it has access to large amounts of quickly-eaten feed.
An adult horse is estimated to be able to consume forage equivalent to about 2% of its body weight. This means that the horse must have at least 1.5 kg of dry matter per kg of body weight per day. For example, a horse weighing 500 kg is to have at least 7.5 kg of dry matter per day. Since haylage can contain a higher concentration of nutrients than ordinary hay, the amount of hard feed should be reduced in relation to the amount of haylage given. This is not just more economical for you as owner, it is also more nutritionally appropriate for your horse. Studies have shown that horses allowed to choose between hay, haylage and silage show a clear preference for haylage.
It is however important to bear in mind that haylage contains more water than ordinary hay, which means that more of it must be fed. This is good for the horse, which is able to eat for longer and keep its digestive functions going for a longer period – an optimal situation. In its natural environment, a horse will graze for 14–18 hours a day, so that its digestive functions are working consistently and in balance. The longest break from eating that a naturally grazing horse will take is about 4 hours. 90% of all natural grazing breaks are about 2 hours long. The horse is a specialised herbivore with a digestive system that has evolved to digest and metabolise food that contains a lot of plant fibres.
Levels of the amino acid lysine in grass; the horse’s requirements
The amount of forage that a horse must eat to meet its energy needs should also meet its protein requirements. We can accept lower protein levels in forage for mature horses and performance horses than we would for breeding stock and growing youngstock. Protein levels in forage are strongly related to the stage at which the grass was mown. Levels of amino acids – primarily lysine and methionine – reflect protein content. These amino acids are the ones that are believed to be growth-limiting for young horses. Lysine is the number one growth-limiting amino acid, because it is the one with the greatest shortfalls in relation to equine dietary requirements. If we make sure that the horse is getting enough lysine, then we know that it is getting enough of the other amino acids.
The proteins in a mare’s milk contain balanced amounts of essential amino acids specially adapted to the needs of the growing foal. The balance between lysine and other amino acids in mare’s milk agrees well with that of the horse’s musculature. Forage with high levels of protein contains amino acids at levels that agree well with horses’ requirements. Diets containing a lot of cereals should be supplemented with protein feed, since cereals are inferior to forage in providing the horse with the amino acids that it needs. (Oats contain most lysine compared to other cereals).
How many kg of forage a day should I feed my horse, based on the dry matter (DM) content of the forage and my horse’s weight?
|Forage||DM, %||1 kg DM as kg of forage (e.g. 1/0.84 = 1.2 kg forage)|
|Hay||84%||1,2 kg feed|
|Haylage||45%||2,2 kg feed|
|Haylage||50%||2,0 kg feed|
|Haylage||55%||1,8 kg feed|
|Haylage||60%||1,7 kg feed|
|Haylage||65%||1,5 kg feed|
|Haylage||70%||1,4 kg feed|
Horse feed Calculation
1 kg DM, measured in %, is converted to the corresponding amount of kg of forage (the more water in the haylage, the more forage per kg of dry matter you have to feed).
For example: a horse weighing 500 kg is to be fed a minimum of 1.5 kg DM per 100 kg body weight and day, which means that the horse should be given 7.5 kg of DM per day. 1 kg DM in hay is equivalent to 1.2 kg of hay, which means that the horse needs a minimum of 9 kg of hay per day.
How to calculate Horse feeding
1.2 kg DM hay x 7.5 kg DM recommended for the horse per day = 9 kg hay/day/horse (or 7.5 kg DM hay/0.84 (DM in hay) = 9 kg hay)
Using the same example for haylage with 55% DM: 1.5 kg DM x 5.00 (500 kg body weight) = 7.5 kg DM, recommended feeding per horse. 1 kg of DM at 55% DM haylage is equivalent to 1.8 kg haylage. Thus: 1.8 kg of haylage x 7.5 kg DM (recommended feed per day/horse) = 13.5 kg haylage per day/horse.