Rumen Superchargers Still Not Very Super

Beefs and Beliefs

Scientists say enzyme therapy to aid forage digestion still only a minor help and the economics remains in question.

Published on: July 11, 2013

I spent all morning yesterday listening to animal scientists talk about whether enzymes can help rumen bugs digest more of the lignin and other indigestible parts of forages.

I'm not sure I came away with a satisfactory answer.

This seminar was at the Joint Annual Meeting of the American Society of Animal Science and the American Dairy Science Association in Indianapolis, Indiana, a weeklong national affair that brings together more than 3,000 animal scientists each year.

The fact is I've been quizzing animal scientists about this topic of improving rumen digestion quite a bit over the last couple years, considering that energy is the most lacking component of forage diets. One of those scientists, Jenny Jennings of Alltech, tells me their product, Fibrozyme, does improve digestion of the indigestible part of forages and it can be fed on pasture.

I heard similar things in the seminar yesterday but the gains all look small and I'm unsure about the economics, especially for the extensive pasture conditions of most beef operations.

For the record, plants fundamentally make sugars and starches during photosynthesis and then turn those carbohydrates into structural materials such as cellulose and hemicellulose. So even the most indigestible lignin contains energy. It's just not very available.

I once heard someone say, "If you can burn it, then it contains energy. But that doesn't mean it's digestible."

One of the scientists yesterday, Jong-Su Eun of Utah State University, said typically only 50% of forage consumed by ruminants is digested.

Quite a bit of this seminar was done by dairy scientists and often this is the case. The dairy folks are all over this and other efficiency issues because their cattle labor under much greater energy deficits than do our beef cattle.

Here are a few tidbits I found interesting.

Gbola Adesogan of the University of Florida described in some detail how he screened 18 different enzymes and found the five most effective ones to test. He found these five were highly affected by rumen pH and temperature. He also found some improvements in feed efficiency and in milk production with some. These were small, however. I don't recall anything reaching even 5%. They also were most effective only during the early, heaviest stage of lactation.

Then Adesogan came up with a chart of optimum rates for each of the five. However, when he weighed the economics of their use he found the optimum was frequently a lower rate than the one which produced the greatest performance.

I left the seminar with the feeling I had once again run into a dead end on finding that elusive ruminant supercharger. I know it's an old and well-worn dream but I'm still watching.

In the meantime it looks to me like better forage management and judicious supplementation when it makes economic sense remain the mantra.