Basics of Horse Feed StorageBy Dr. Kathleen Crandell · January 18, 2012
Choosing and purchasing the right feed products for your horse is an important step in providing optimal nutrition. What happens to feeds or supplements once they arrive at the farm is equally important, as horses should be offered only fresh, unadulterated products. Appropriate storage is therefore an important horse-keeping consideration.
The type of feed affects its shelf life. Straight whole grains can conceivably be stored for years as long as they are kept under ideal conditions (low moisture [<13%], low humidity, few or no broken kernels, free from insects or rodents). On the other hand, commercial grain mixes have a shorter shelf life. Most manufacturers will recommend consumption of the feed within 30-60 days of manufacture if the product is stored under proper conditions. If stored under ideal conditions, the feed could possibly last longer, but placing an expiration date on the package protects the manufacturer from liability should problems occur if the feed is consumed after that date.
What are the proper conditions? Factors that affect shelf life of feed include humidity and temperature of the storage facility (including both the feed dealer’s warehouse and the farm), presence of rodents or insects, and exposure to air. High temperatures can speed natural degradation of feed, especially when there is also high humidity. Degradation includes growth of mold and bacteria as well as oxidation that results in loss of vitamins and causes rancidity of essential fatty acids. The most important single factor affecting stability of grain is humidity. At a relative humidity in excess of 70%, deterioration will occur even at temperatures as low as 40° F (5° C).
Feed bags stored on pallets are less susceptible to moisture damage than those stacked on the ground or on concrete. Grain in a sealed bag should last longer than that in an open bag. Once the bag has been opened by humans or chewed into by rodents, it is imperative to use the feed quickly because exposure to air will increase the opportunity for development of molds, oxidation, and insect invasion. Open bags can be stored in containers or dumped into bins to protect the feed from further ravage by pests, but once in the bins, the product should be used within a reasonable amount of time.
Pelleted feeds may have a longer shelf life than some textured feeds because of their lower moisture content as well as the heat treatment they go through during manufacture. With a greater moisture content, textured feeds will have a shorter shelf life if stored in hot, humid conditions.
Susceptibility of high-fat feeds to rancidity is reduced by the use of preservatives. Manufacturers include preservatives in feeds to inhibit mold growth, but they can only slow the growth, not prevent it. By the time humans can detect rancidity in a feed through smell (acrid instead of sweet), horses will surely have sensed it because they are more sensitive to spoilage. They may have already refused the feed.
Feeds contaminated with visible mold should be discarded immediately. Horses are much more sensitive to molds and bacteria than some other livestock.
If it is not possible to store feeds in proper conditions (cool temperatures, low humidity, and free from rodents and insect exposure), buying in small quantities that will be used within 10-14 days is the best solution for providing safe, high-quality nutrition to a horse.