Question

When it gets really cold, some of my horse feed freezes into a solid block, making it difficult for me to scoop. I can deal with that, but is it safe for my horses to eat?

Answer

No matter how frigid it gets, plain oats will stay slippery, free-flowing, and easy to handle. However, as ingredients are added to create textured feeds—also known as sweet feeds—the likelihood of feeds becoming solid in subfreezing temperatures increases. The ingredients that contribute to this change include vegetable oil and molasses, both of which increase in viscosity as temperatures drop. Viscosity is the measure of a liquid’s resistance to flow.

While they generally do not freeze solid as water does at a specific temperature, oils become so viscous they are essentially solidified when subjected to very cold temperatures. Soybean oil, a common ingredient in feeds, is thought to reach this point at about 3° F (-16° C), while corn oil and canola oil have higher “freezing” points, 12° F (-11° C) and 14° F (-10° F). Similarly, molasses becomes much thicker and difficult to pour as it is exposed to colder temperatures. The result, at least in terms of sweet feed, can be an impenetrable brick of feed, as you mention.

“Some feed manufacturers understand this problem and avoid it by reducing the amount of molasses added to feeds in the winter,” said Mike Lennox, who oversees formulation and quality assurance at Kentucky Equine Research. “Other manufacturers may change the composition of the molasses by adding oil or altering the concentration of sugar.”

While feed becomes difficult, sometimes impossible, to scoop in the traditional manner, frozen feed is in no way harmful to horses. Most horses will consume the feed as they normally would. A word of caution: be careful to break up chunks of feed. If large chunks are fed intact, they could represent a choking hazard, especially for greedy eaters.

While textured feeds remain popular, horse owners that contend with cold temperatures for long periods of time often rely on pelleted feeds.