The behaviour and welfare of stabled horses can be drastically changed by the way in which they are offered their hay, researchers have found.
The study team in France found that the way in which hay is fed not only had the potential to influence behaviour and welfare, but the horse-human relationship.
Researchers Céline Rochais, Séverine Henry and Martine Hausberger set out to examine how different devices for feeding roughage affected horse behaviour.
Their study involved the observation of 24 geldings and 14 mares at the French National Stud in Saumur, each housed in 3-metre by 3-metre straw-bedded stalls. Each stall had an automatic drinker and each horse received commercial pellets, distributed by an automatic feeder. The horses each received a daily ration of 9 kilograms of hay.
The researchers, writing in the journal Applied Animal Behaviour Science, noted that devices such as hay-nets/bags and “slow-feeders” had been developed in a bid to increase the time horses spent feeding on roughage, mimicking their natural grazing behaviour.
The horses in the study received their hay one of three ways – either on the ground in the stall, in hay-bags hung at one of the stall walls, or in a plastic slow-feeder positioned in the corner of their stall.
The slow feeder was known as a Pacefeeder and was sourced from Ireland. They are a triangular plastic container standing 780mm high in which the hay is placed and covered with a plate with holes, which descends as the hay is eaten.
All horses were submitted in a random order to the three hay-feeding methods for three weeks each time.
The hay was fed morning and afternoon when given on the ground or in the hay-bag, whereas the full ration was put in the slow feeder each morning.
Rochais and her colleagues found that both the hay-bag and the slow-feeder increased feeding time when compared to the hay being fed on the ground.
“While the hay-bag distribution was associated with an increase of frustration behaviours, the slow-feeder reduced ‘undesirable’ behaviours, such as stereotypic behaviours, and increased ‘friendliness’ towards humans,” the researchers, all from the University of Rennes 1, reported.
These results emphasized the importance of identifying feeding strategies and/or devices that improved feeding distribution and horse welfare, they said.
“This study reveals that behaviour and welfare of horses could be drastically changed by the method in which stalled horses were offered food, i.e. feeding system chosen,” they wrote.
The slow-feeder appeared to be associated with a more positive state – that is, less frustration and fewer stereotypic and abnormal repetitive behaviours when compared to being fed on the ground. The increase in positive reactions towards humans suggested a boost in horses’ welfare state, they said.
However, despite its positive effects on the time spent feeding on hay, the hay-bag was associated with the development of device-directed frustration behaviours. These included more time spent with ears back than in both the other hayfeeding methods, and in stereotypic behaviours, compared to the slow-feeder situation.
These results were remarkable, they said, in that the behavioural modifications were observed after the horses had spent only three weeks using the method considered.
The use of the slow-feeder seemed to have several advantages over a hay-bag, they said. There was still hay 11 hours after the slow-feeder was filled, whereas the hay-bags were often empty by midday, four hours after their morning fill and three hours before they were refilled with the rest of the day’s ration.
“In addition, horses with the hay-bag showed more frustration towards the device per se, including pulling on the hay-bag with teeth, pushing with the head, etc. No such behaviour was observed with the slow-feeder.
“It was evident during observations that the hay-bag position in the stall (i.e. hung at the wall) involved hay-bag movements and hence, difficulties in feeding on the hay.”
In conclusion, they said seemingly insignificant changes in the way the hay was fed had large consequences on the internal state of horses.
“While all three modalities tested here on the same horses aimed at increasing the time spent feeding, they did clearly affect horses’ behaviour, including their relationship towards humans.
“The slow-feeder reduced undesired behaviours, including aggressiveness towards humans while the hay-bag tended to increase frustration.
“It is therefore proposed that more thought be given to potential strategies (and devices) when feeding stalled horses, that aim at improving feeding time and promote welfare and reduce frustration.”
“Hay-bags” and “Slow feeders”: Testing their impact on horse behaviour and welfare
C Rochais, S Henry, M Hausberger