Animal feed is a complex food product composed predominantly of raw agricultural ingredients such as forage like hay and alfalfa and partially refined ingredients like soy bean meal, cracked corn kernels and wheat middlings. The relative quantities of these ingredients vary with location, season, species being fed and the cost of the ingredient.
Animals are not capable of digesting all the plant matter they consume due to a number of factors; low levels of some digestive enzymes, short residence time of the food in the digestive system or the lack of specific enzymes.
The purpose of adding enzymes to feed is to improve the utilization of the feed, increasing the amount of nutrients available to the animals which improves their health, lowers feed cost for the farmers and reduces farm waste volume. The benefit to the consumer has been lower prices for meat in the supermarket and restaurants relative to 50 years ago.