Does your horse turn his nose up when you offer him a new treat or a different type of hay? What you’re actually observing is so-called food neophobia (in other words, a fear of new foods). While we’ve long been anecdotally describing our horses as being fussy or picky eaters, only recently have researchers conducted studies to take a closer look at horses’ neophobic and neophilic (basically, enjoying new foods) responses to different types of food.

In particular, Mariette van den Berg, BS, MS, and colleagues at the University of New England, in Armidale, New South Wales, Australia, investigated how a feed’s energy level (high- or low-calorie) affected the horse’s acceptance of a new but nutritious forage compared to a familiar forage.

The team employed 12 mature mares with body condition scores (BCS) between 3 and 5 (on a 9-point scale) for their eight-week study. Prior to beginning treatment diets and in between treatments, all horses consumed a maintenance diet that met 100% of their recommended daily intake (RDI) of energy. Between Weeks 1 through 3 and 5 through 7, the researchers randomly assigned horses to consume one of two treatment diets:

• A low-energy (LE) diet, which included 80% of the RDI of energy; or
• A high-energy (HE) diet, which contained 120% of the RDI of energy.

The researchers tested horses’ preferences for familiar and novel forages in two stages: a two-choice test followed by a final preference test. Each horse participated in multiple 10-minute two-choice tests between pairs of a familiar forage (oat or alfalfa chaff) and a novel forage (willow, bamboo, saltbush, or tagasaste leaf chaff). “These were matched based on their nutritional content (energy/protein pairing), and the total amount of food offered did not exceed more than 10% of the RDI of energy,” van den Berg said