A: This is a concern that I hear fairly frequently. We hear a lot regarding processed foods and human nutrition and the fact that they’re not the best choice. I think it’s important to fully understand why and how feeds are processed when thinking about equine feed.
Wait. Hay is Processed Feed?
Equine feed processing takes many forms. For example, we don’t often think about it this way, but hay is processed grass: Farmers cut, dry, and then bale it. These are all processing steps that allow forage suppliers to store and sell hay in other geographic locations or when horses don’t have pasture access.
This hay might be further chopped and then turned into hay pellet, a process that involves heat in the form of steam and the application of pressure to form the pellets. All this processing increases the cost of the product; however, it makes the hay more digestible because the relative surface area of the hay has been increased by chopping it more finely to make pellets. The resulting product requires less chewing to eat, which is beneficial for horses with poor teeth, but might be a less beneficial choice for horses with good teeth, because chewing results in stomach-acid-buffering saliva.
Pros and Cons for Horse Health
I think that rather than demonizing all processing, it’s important to step back and be objective about the form of processing and its pros and cons.
Would I recommend feeding a hay pellet to a healthy horse with no dental issues that does very well on hay if its is plentiful and affordable? Probably not, because of reduced chew time and the fact that the greater digestibility might result in the horse needing less forage. While this could reduce manure production and help decrease feed costs, eating more forage is often better for horses. However, if I have a senior horse with poor teeth or a hard keeper who struggles with weight maintenance, hay pellets could offer a great solution, and I might be willing to live with the reduced chew time because of these other benefits. It’s a matter of balancing the pros and cons for the individual horse. To me it’s unreasonable to label all processing as bad.
We change the structure of some ingredients fed to horses—most commonly starch—through processing. The way that starch in barley, corn, and wheat is structured makes it somewhat resistant to digestion in the horse’s small intestine. This can lead to starch that isn’t fully digested entering the hindgut, where it can lead to rapid fermentation and disruption of beneficial intestinal bacterial. Research has shown that if heat treated, however, the starch in these grains becomes more digestible and less likely to enter the hindgut. Therefore, these grains are typically fed after being steam flaked or extruded. Traditionally people would cook the grains whole on their stove tops.
Flaking and extruding also have the benefit of increasing the grains relative surface area, resulting in a greater area for digestive enzymes to work on. These processing techniques have positive health implications for the horse. Interestingly the starch in oats is far more digestible and does not need to be heat processed to increase absorption, which is one of the reasons oats are a relatively safe grain to feed horses.
When it comes to oats, I tend to recommend feeding whole (unprocessed) oats to horses with good teeth rather than rolled or crimped oats, because these processing techniques do less for digestion and open the grain up to oxygen and potentially greater spoilage.
Owners often believe that they’re seeing whole undigested grain in their horse’s manure when they feed whole oats, but it’s worth checking to ensure that it isn’t just the empty husk. If it is whole grain, have your horse’s teeth checked and consider feeling crimped or rolled oats instead.
Other ways that processing can change the chemical composition of feeds is by rendering nonnutritional compounds inert. Soybeans provide a great balance of plant-based amino acids in many horse feeds; however, they contain phytic acid that can complex, with certain minerals reducing their absorption. Heat processing inactivates the phytic acid so this isn’t an issue.
Beet Pulp and Other (Nutritious, Low-Starch) Byproducts
Byproducts of other processing techniques are often used as feed ingredients, for example beet pulp and wheat millrun. Often thought of as floor sweepings, wheat millrun or wheat mids aren’t sweepings at all. They’re the wheat grain parts left after flour production that have a far lower starch content than the original grain, while providing a rich source of key vitamins and a good amount of protein as well as calories.
Because owners have requested that the feed industry provide feeds with lower starch content but that still provide ample calories for performance, wheat millrun and mids have provided a great solution. Yet they are perhaps some of the most processed ingredients in horse feeds.
Certainly, there’s the risk that during processing some nutrients are negatively impacted, especially those that aren’t heat-stable. Manufacturers might then need to add these nutrients back in other forms. However, in many cases feed processing can benefit your horse. Before deciding all forms of feed processing are detrimental consider the type of processing and the pros and cons for each before determining whether it is something that might be a benefit or detriment to your horse. I personally find that in most cases the processing benefits outweigh the cons.