Nothing beats a freshly cooked meal, and this holds true not only for humans, but for animals, too. Perhaps it is not the exact same thing, but a stale, oxidized meal is certainly not the best way to ensure high feed intake in modern hyper-producing animals.
So, how long does feed remain fresh? The right answer is, of course, "not a single day." Feed components start deteriorating as soon as they undergo the feed mixing process. Here are some examples:
- Some vitamins lose potency when intermixed with certain trace minerals.
- Lipids start deteriorating (oxidized) as soon as they come into contact with oxygen.
- Cooked starch starts going "stale" as soon as it cools down.
Now, feed does not become unsuitable to consume that fast, but the point is made when we consider the significant time required from mixing feed to actually being consumed by animals -- the more so in the case of commercially produced feeds. Thus, the golden rule is to have animals consume feed within three months from its production date.
But, this is the rule, and it should be adjusted accordingly. Feed exposed to high temperature (and) or high humidity, or feeds containing increased levels of sensitive ingredients, will have a reduced shelf life; this is why some additives are used to prolong their useful life. For example, a feed rich in lactose and lysine lost about 10 percent of its lysine potency within a week when exposed to the normal conditions found inside a typical piglet nursery facility. On the other hand, a broiler diet without any reducing sugars, stored in an outside silo, would not be expected to have such dramatic losses. To this effect, it always pays to heed the old advice of keeping sensitive feeds to a dark, cool and dry place.