February 2014 - How much do horses eat when they are kept in a group?
The article is written by Dr. Dag Austbø at the Norwegian University of Life Sciences institution. Dr. Dag Austbø and Dr. Knut Hove are two of the key people behind the development of PC-Horse. Their scientific work and international networks contribute to the continued development of PC-Horse and to secure that our calculations are based on established scientific data.
Many horses are kept outdoors in groups during the daytime and receive a substantial part of their roughage outdoors . Under such conditions it is difficult to know exactly how much each horse eats.
Competition for feed
Many factors affect how much each individual horse eats. In any group of horses, there will always be a hierarchy, where the dominant horses will ensure for themselves the best access to feed and will chase away the less dominant individuals. There are also individual differences in appetite. It is therefore important that the horses have enough space and that feeds are positioned to cause the least possible conflicts between horses. If the horses have too little space, aggression levels will increase considerably.
It has been demonstrated that the main factors affecting the social order of a herd are age and how long each individual has been in the group. Young horses are always ranked lower than adult horses. It is therefore important to create separate groups for young and adult horses respectively. Within any herd of young or of older horses, there will always be a hierarchy that affects each individual's access to the feed. There may be individuals with aggressive, dominant behaviour or else very submissive individuals that should preferably be taken out of the group. Although separated from their group, they can still have eye contact with the others. This will help to stimulate their appetite.
It is very important that the person responsible observes each horse closely. Dominant horses tend to put on weight and can grow too fat, while submissive individuals may lose condition and become too thin. Corrections to feeding will have to be made individually for horses indoors in the evening and early morning.
What does the literature say on voluntary feed intake of horses?
How much can we expect the horses to eat? In the U.S. Nutrient Requirements of Horses (NRC-2007) , which is an important reference work for horse feeding, figures for voluntary feed intake is given. The results show that both young and adult horses will have a daily intake of between 2 kg and 3 kg dry feed (dry matter) per 100 kg body weight. Highest feed intake will be from mixed roughage and concentrate rations. If the horses are being fed roughage only, the total feed intake can be lowered slightly, but this depends largely on the quality of the roughage. Given roughage of good quality (high energy) the horses will be able to maintain a high level of voluntary feed intake.
What does this mean in practice?
Daily intake of roughage varies based on feed quality, production classes, individual appetite and each individual's place in the herd hierarchy. This means that we must observe horses in a herd closely and make corrections to the feed offered each individual at night-time or early morning to avoid some individuals growing too fat or too thin.
Giving young horses special attention
Young horses have a high energy requirement per kg body weight. It is therefore particularly important that roughage for young horses is of high quality with a satisfactory content for both energy and protein. This is to ensure optimal growth and development. If we then manage to create conditions for young horses to maintain a high intake of roughage, we can reduce the use of concentrates.