What is the difference between a VFD expiration date and duration of use?

• A. Expiration date: can't use after this; Duration of Use: length of time the feed containing the VFD drug is allowed to be fed to the animals
• B. Expiration date: the time the product was issued; Duration of use: the time the product is manufactured
• C. Expiration date: the length of time the feed can be used; Duration of use: can't use after this
• D. Expiration date: the time the product was issued; Duration of use: the time the feed is produced

Answer: (A)

The main idea is how time is defined for a VFD medicated feed. The expiration date is the last day you can use the product because it may lose potency or safety after that date. The duration of use is the actual allowed period that the feed containing the VFD drug can be fed to animals under the veterinarian’s directive—the window during which the medication may be given, not the product’s shelf life.

So, the correct distinction is: expiration date = cannot use after this date; duration of use = how long the medicated feed may be fed to animals under the VFD order. The other statements mix up when the product was issued or manufactured with how long you may actually feed the medicated product.