Ration Consistency Is More Important than Ration Balancing
May 22, 2011
Each cow’s microbial community wants to maintain equilibrium in the rumen. That’s why it’s so important to avoid sudden ration changes and feed consistently.
By Rick Lundquist, Ph.D.
Ever wonder why some herds seem to have consistently high production on relatively simple rations? It may be because they are fed the same way every day with very few changes.
Consistency is very important to a cow or, more correctly, to a cow’s microbial community. A ration that is fine-tuned and balanced for essential nutrients is our goal. But if it is mixed or fed inconsistently or the ingredients change frequently, the results will be inconsistent too. It’s better to feed a ration that’s not balanced but fed consistently.
I attended a conference in Italy last week where Dr. Dave Mertens presented a paper on fiber degradation and the factors that affect it. One very interesting slide showed what happened to the microbial community of two rumen fistulated cows when each cow’s rumen fluid was almost completely exchanged with the other. The cows were fed the same rations. Individual cows have very distinct microbial populations, even when fed identical rations. The microbial composition seems to be uniquely adapted to the rumen conditions of the host cow.
After the rumen fluid exchange, the original microbial community tried to re-establish itself for each individual cow. But it took 14 days in one cow and 62 days in the other cow. It wasn’t a gradual transformation back to the original microbial composition either. There were all kinds of “microbial gyrations” along the way until the microbial community finally resembled each cow’s original demographics.
I think this helps to illustrate the importance of a consistent ration. Think what must go on in the rumen after a major silage change, with different fermentation profiles in the silage -- or the daily havoc that inconsistent mixing and hence, inconsistent diet might wreak on the bugs in the rumen. Each cow’s microbial community wants to maintain equilibrium in the rumen. That’s why it’s so important to avoid sudden ration changes and feed consistently.
Contact Lundquist at firstname.lastname@example.org.