Effect of complementary feeds on the chewing activity of horses

Originally a grassland animal, horses are adapted to a continuous intake of small amounts of feed. Today, horses are primarily kept in box-housing systems and feed intake duration has gained importance. In this study, four complementary feeds with crude fiber content of 10%, 12%, 14.5% and 18% and differently processed (muesli, structured muesli or pellet) were tested on eight Haflinger horses. The intake time of meadow hay was used as a control. Feed intake duration and chewing movements were recorded with an EquiWatch® halter. For the different complementary feeds, the intake duration ranged from 11.6 to 16 min per kg and the number of chewing movements ranged from1136 to 1472 per kg feed. The two complementary feeds with the highest crude fibre contents resulted in the longest feed intake duration. In contrast, the mean intake duration for hay was 33 ± 4.2 min per kg, with 2644 ± 338 chewing movements per kg. Complementary feeds, even when they contain ingredients with higher crude fibre content such as straw or spelt husks, cannot compete with hay feeding in terms of intake duration and chewing activity. With regard to digestive processes in the equine gastrointestinal tract, it is therefore advisable to limit the intake of complementary feed.