Using exogenous fibrinolytic enzymes has been proposed as a method to increase fiber digestibility mainly in low-quality feeds. Specifically, xylanase is an enzyme that helps break down β-1,4-linked backbone of arabinoxylans from cell walls, and it has been reported that its supplementation increases milk yield in lactating dairy cows.
Dairy cattle and other ruminants are biologically designed to convert forages and other fibrous feeds into high quality products such as meat and milk. Forages are in general the least expensive source of energy for dairy cows. However, the efficiency of converting forages to milk is limited by the digestibility of forage cell walls.