Hay preferences in horses versus selection by their owners

The objective of the present study was to evaluate the differences in the selection behaviour by horses and by their owners given a choice of three hay types differing in chemical and nutritional composition. Horse groups included 12 French mountain (FM) stallions, 12 Icelandic (IS) and 12 warmblood horses (WB), with the latter groups consisting of mares and geldings. Hays were offered in a free choice experiment over a period of six consecutive days (baseline choice on day 1, adaption period from day 2–5 and a final preference test on day 6). Additionally, the owners of the horses selected among the three hay types, the one which they assumed would best meet their horse's assumed nutritional requirements. Hay types (A, B and C) showed distinct characteristics based on colour, texture morphology and odour and nutrient contents. The latter were analysed with near-infrared spectroscopy. Most horses (69%) preferred hay type B and 31% preferred hay type C, while horses completely avoided hay type A. The group of FM horses exclusively preferred hay B on both test days, the groups of IS and WB horses also showed a preference for hay B, but less pronounced than FM horses choosing both between hay B and C, respectively. Horses did not choose randomly among the hays offered (P < 0.05). In addition, the horses hay preference was influenced by their group assignment (P < 0.05) which, however, cannot be generalized to breed or gender (mares, stallions or geldings). The content of crude protein (r = 0.68), and leaves (r = 0.48) of the hay was positively correlated with the preference of the horses for that particular hay type, although correlations were moderate. Among the owners, 42% chose hay type A, which was completely avoided by the horses, while approximately 30% of the owners chose either hay type B or C, which were richer in energy and protein as the best hay quality for their horses assumed nutritional requirements. Therefore, no significant correlation could be observed between the choice preference of the horses and the selection by the owners. The distinct preference for energy- and protein-rich hay of horses underlines the importance for owners to carefully adjust the hay quality to the horse's activity level and requirements. For horses with lower energy requirements, omission of concentrate feeds, while providing roughage only diets by mixing different hays qualities, appears suitable.