Forage feeding systems

Abstract

Horses are adapted to grass intake and low forage and high cereal intakes are associated with many health problems. Therefore, diets dominated by forage have many advantages but maybe also some limitations. One challenge using forage-dominated diets is the large variation in energy and nutrient content that different harvests and batches may display. A forage analysis of dry matter, estimated energy, crude protein (CP), Ca, P and Mg content (using appropriate methods) is therefore crucial for a successful use of forage-dominated diets, and depending on the requirements of the individual horses, a careful selection of suitable batches must be done. The maximal voluntary intake and intake rate of forage is correlated to fiber content. The organic matter digestibility is highly dependent on the fibre content and the importance of the hindgut digestion increases with increased levels of forage in the diet. In horses fed a forage-only diet a higher faecal microbial stability has been observed compared to a concentrate rich diet. By selecting forage with proper energy and CP content, forageonly diets may provide all energy and CP (and amino acids) that horses need, including athletic horses, growing horses and mares in peak lactation. If such forages are not available, the forage has to be supplemented based on the forage analysis. However, in many pleasure and sedentary horses the forage allowance has to be restricted because of the high consumption capacity and the risk for obesity. This could be a welfare problem and forages with a low energy and high fibre content should be used to extend feed intake time. It is concluded that: (1) all healthy horses can (after adaptation) meet their energy and protein requirements on forage-only diets but forage batches have to be selected based on feed analyses; (2) changes between forage batches should be made gradually; (3) forage diets shall be supplemented with minerals based on the forage analysis; (4) supplementation with vitamin A and E could be considered in growing and heavily exercising horses; (5) There is a need for increased availability of forages with different nutritional values; and (6) there is a need for information and education of horse owners on the use of forages.