This study sought to investigate feeding behaviour and diet selection of horses exposed to concentrate feed of differing flavours and nutrient contents in different situations. Firstly behaviour was studied in a simple choice test. The results showed that when the
horses have no previous experience of the testing procedure, they sample the options equally. However, when the horses have previously been exposed to a choice with a different flavour on one side, the selection of some horses appears to be affected by previously formed associations between flavour and position.
Secondly, the ability of horses to form associations between flavours of foods and the post-ingestive consequences were investigated. When presented with a choice between distinctly flavoured higher and lower energy diets, horses showed a shift in preference
towards the flavour associated with the higher energy. When the flavours were subsequently presented in iso-energetic options, the horses tended to consume equal amounts of both flavours.
The ability of the horses to discriminate between the higher and lower energy diets was then investigated to determine if the higher energy was intrinsically more palatable. When presented with a choice between the higher and lower energy diets, only 2 out of 8 horses showed a preference for the higher energy and 1 horse showed a preference for the lower energy. The ability of added cue flavours to predominate and mask the orosensory characteristics of the higher and lower energy diets was investigated by exposing the horses to a choice between mint flavoured higher energy and mint flavoured lower energy. No horses discriminated between the diets.
The effect of exercise on behaviour in a choice test was then investigated. No effect was seen on intake rate, number of switches between buckets and time spent with the first bucket before sampling the second, when given a choice between iso-energetic options.
When exposed to a choice of a higher or lower energy diet following a period of rest, preference for the higher energy was greater than following a period of lungeing. However, when exposed to a choice between a higher and a lower energy diet 3 times per day, preference for the higher energy was less when horses were rested, than on days when horses were exercised for between 1 and 3 hours per day. The inconsistent results are likely to relate to differences in management and level of exercise.
This study suggests that the horse may be able to adapt its behaviour appropriately when provided with a choice of concentrate feeds in some situations, but information is still required on the physiological mechanisms and their behavioural control mechanisms