A: Spoilage is more of a concern with in commercial feed than with stored hay.
You can store hay indefinitely if the stack is managed correctly; although, in humid climates, using hay within three years of harvest is ideal. Hay growers need to bale it at correct moisture levels because if it’s baled too damp the hay will generate heat, which leads to molding. Barn storage, especially long term, is best as it will prevent damage from weather. Rodents and other animals should be kept out and hay should be stored off the floor. Bales places directly on concrete could sweat and, if placed on the ground, might wick up moisture, which could result is losing up to 50% of your bottom bales. Placing hay on pallets or a thick layer of old hay or straw is recommended.
Long-term hay storage will result in some nutritional losses. Most will occur in the first couple of months with overall dry matter losses up to about 5% in the first year. After the first couple of months losses in protein and energy are minimal such that the energy and protein profile of hay that is a year or two old will be fairly similar to when it was about six months old.
The one nutrient that is lost in storage is vitamin A or, more specifically the pre-cursor to vitamin A, beta-carotene. Hay loses about 10% of its beta-carotene per month, so year-old hay is not a good source of this important fat soluble vitamin. However many commercial feeds and supplements provide additional vitamin A sources at levels greater than requirement, so the horse’s needs should be met by feeding these.
One thing to note is that aged hay can lose its “nose,” meaning that it might no longer smell sweet the way that hay fresh off the field smells. Don’t be put off by this lack of smell.
Grains and Commercial Feeds
When it comes to grains and commercial feeds, unprocessed whole grains might last for a long time. For example, whole oats are good for 12 months if stored correctly. However, once rolled it might only take three weeks in the warm summer months before rancidity occurs.
Heat processed feeds typically have a longer storage length (think hay or alfalfa pellets) due to the fact that the heat kills off some bacteria. Generally, experts accept that commercial pellets are viable for about six months. Textured feeds are best used within three months of manufacture date.
The higher the fat content of a feed the more at risk it is of going rancid. Consider storing lower quantities of feeds with higher fat contents (those with 8% fat or more). Not only are there concerns about the grain components of commercial feeds, but most vitamins and some minerals added feeds lose efficacy after about three months.
Weigh how many pounds of feed you are feeding each day and multiply this by 90 to determine how much feed you will actually use in three months, and then do not buy more than this amount at one time. Be cautious, though, because even three months might be too long to store some feeds in certain climates at specific times of year.
Understanding Dates on Feed Tags
How do you know how old a feed is when you buy it given they don’t come with use-by dates? Most feed companies stamp the manufacture date on the bag’s seam. Different companies use different nomenclature. I’ve seen several different feed-bag dating methods; for example 5MAR09 for 2015 March 9, 2015, or the Julian date 2016080, which is the 80th day of 2016 (or March 21).
Bottom line: Check these dates when you purchase feed and make sure to use textured feed within 90 days of this date and pelleted feed within 180 days.
Do you buy your horse feed and/or hay in bulk?