The competition for environmental resources in horse herds can result in agonistic behaviors (behaviors associated with conflict) with the dominant animal usually winning. These behaviors may result in increased stress, lower growth, and even lower survival.
There is also disagreement on the most appropriate height of feed troughs for horses. Some claim that the trough must be positioned above the height of the horse’s chest allowing for the correct angulation of the horse’s neck. In contrast, some suggest the use of troughs at ground level allow greater elongation of the neck and back of the animal and to emulate a “natural” grazing position. Researchers from Brazil recently evaluated whether the distance, proportion and height of feeding troughs affect agonistic behaviors in group fed horses.
Researchers simultaneously varied three independent factors: the distance between the feeding troughs (5 feet or 33 feet) the proportion of troughs (1 trough per horse or 1.5 troughs per horse) and the height of feed troughs (ground level or 2.3 feet from the ground). Eight adult geldings were used and agonistic behaviors (bite, kick, rush and pinned back ears) were recorded for 30 minutes while horses were feeding. Pinned back ears was the most frequently observed agonistic behavior. Initially, a distance of 33 feet between troughs, ground level feeding and 1.5 troughs per horse reduced pinned back ears. However, as the horses established a hierarchy, only distance between troughs reduced pinned back ears. When it came to kicking behavior a distance of 33 feet and a trough height of 2.3 feet reduced this behavior.
Researchers concluded that both the distance between feeding troughs and height affected agonistic behaviors in group fed horses. Researcher recommend that feed troughs should be spaced at least 33 feet apart to reduce agonistic behavior, regardless of the social hierarchy of the herd.
For more information on this study, click here.
This article was written by Krishona Martinson, PhD, University of Minnesota. You can click here to subscribe to the University of Minnesota horse newsletter.