Lower milk prices and higher feed costs have producers looking for alternatives to improve feed efficiency and budgets. Forages are in general the least expensive source of energy. However, the efficiency of converting forages to milk is limited by the digestibility of its fiber.
Under ideal conditions, total diet digestibility is still generally less than 65 percent. Fiber-degrading enzymes added to the forage fraction of the ration were introduced to the feed-additive market as an alternative method of improving energy availability.
Feed enzymes for ruminants are those that degrade the principle fiber fractions in forages: cellulose and hemicellulose. They are mostly fungal and bacterial in origin. Enzyme products have been applied to different portions of the diets, including forage, concentrate, or complete TMR either in liquid or in powder forms. It has been suggested that their use may allow dairy producers to feed higher forage diets without compromising energy intake and milk production.
What we know so far
Responses to adding fiber-degrading enzymes to dairy cow diets has been variable. Some of this variation can be explained by the initial design of most commercial enzyme products for nonfeed applications. Their use in rations was relatively minor until recently given their previously high cost, inconsistent response, and the potential of other emerging technologies to improve animal performance.
Feeding fiber-degrading enzymes to dairy cows has usually been associated with additional feed intake. Some researchers attribute this effect to improved palatability of the forage as a result of sugars released by the enzymes. Another possible explanation is that more fiber degradation in the rumen speeds passage of feed particles reducing gut fill and allowing the cow to reinitiate feed consumption.
Continue reading this article published in Hoard’s Dairyman.
