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Researchers look closely at feed digestion

A University of Minnesota research project is looking into exactly what happens when cattle eat various forages.

Dr. Isaac Salfer tells Brownfield there’s a difference in how quickly the physical form of different plant species breaks down after it’s chewed. “This is something we’ve talked about in dairy nutrition as a concept for quite a long time, and nobody’s really figured out how to develop an assay on how quickly that feed breaks down under chewing.”

Salfer says the cow’s digestive system reacts to the type of plant and how well it’s chewed. “As it is chewed up, as the particle size gets smaller, it uptakes water more quickly. It kind of sinks to the bottom of the rumen, and it can both digest faster because you get better incorporation of the cellulolytic microbes, and it can also pass out of the rumen and relieve the cow’s inhibition on dry matter intake faster.”

Salfer says that with more farmers including forage from cover crops in the ration, it will be important to know how that impacts the cow’s digestive system. “There’s still a little bit of unknown in terms of what’s the best way to feed those and what the inclusion rate is. I think farmers are kind of figuring that out and a lot of it depends on their inventory and what they’re growing, and what works for them within their system.”

Salfer says more farmers are trying to mix cover crop forage into rations, in part because of increased participation in cover crop incentive programs.

Salfer spoke to Brownfield during the recent Four States Dairy Nutrition and Management Conference in La Crosse, Wisconsin.

AUDIO: Dr. Isaac Salfer discusses research with Brownfield’s Larry Lee.