Ever wonder why your horse might select and prefer one feed over another? Redgate, Cooper, Hall, Eady and Harris reported on feed selection in the Journal of Animal Science (published online February 4, 2014); “Dietary experience modifies horses’ feeding behavior and selection patterns of 3 macronutrient rich diets.”
Some species have been shown to select food based on their macronutrient (fat, carbohydrate, protein) content, while others (like horses) have reportedly selected feeds based on sensory characteristics (scent, etc.).
A challenge in study design to investigate feed selection is the method in which feeds are introduced. The present study aimed to investigate if there were preferences between hydrolysable carbohydrate- (simply digested sugars and starches) protein-, or fat-rich feeds when offered initially all at the same time, as well as after a period of single presentation (one feed type at a time for 3 days), and a repeat of offering the horses a choice of all 3 feed types at the same time. By offering a single feed over a few days, a horse can develop post-ingestive, long-term consequences of a feed (that may be related to energy balance and feed intake behaviour).
The study reports that after a period in which horses had access to the different feeds at a time (and perhaps develops some post-ingestive experience with a feed), horses prefer feeds higher in hydrolysable carbohydrate or protein, compared to fat-rich feeds. The authors conclude that horses appear to be able to associate nutrient content with sensory characteristics of the feed.