Bovines have an amazing ability to turn relatively undigestable grass, hay and other roughage into nutrients and energy. But they can’t claim all the credit. Their rumen—the enormous (50-gallon) fermentation vat that breaks down what they eat—houses billions of bacteria, yeast and protozoa.
These microbes are the real workhorses of digestion, using unique chemical reactions to turn tough cellulose into volatile fatty acids that the cow uses for energy. Talk about teamwork!
When a cow becomes sick, these precious rumen microbes can get sick, too, and even die.Understandably, this has a negative impact on the cow’s digestion.
One remedy to help a sick cow get back on track is a ruminal transplant. This is where new, healthy microbes from another cow are given to the sick one. This happens with the help of an animal called a fistulated cow.
Rumen fistulation is a relatively simple surgery. A healthy animal, typically a large dairy cow, received local anesthetic. Then a rubber portal roughly the size of a dinner plate is inserted into her left flank with a cap.
Using a Fistula
Once inserted, this fistula is permanent and painless and allows for direct access to fresh rumen contents. Simply remove the fistula’s cap, don a long plastic glove and reach in. Immediately, you’ll note the tropical atmosphere. After all, you’re now reaching inside a living creature.
You’ll also notice how dynamic the rumen is. It regularly contracts and churns its contents, sort of like a slow-moving washing machine. Reaching in, you’ll soon encounter half-digested, soggy grass and hay. This is chock-full of precious microbes.
To help a sick cow, you can remove large handfuls of rumen contents. Place this sloppy soup into a plastic bag, keep it warm and quickly transfer it via stomach tube to the sick animal. This transplant of healthy microbes will settle into their new home and quickly repopulate the barren sick rumen. In this way, it helps get the sick cow back to a normal digestive balance.
Where Can I Find a Fistulated Cow?
So where do you find a fistulated cow? Veterinary schools certainly have one. If you live near a large animal veterinary clinic, they may have one, too. Some very large dairies also have one.
Calling your local dairy vet or agricultural extension agent can help you locate one.
Fistulated cows tend to live a relatively cushy life. They aren’t bred or milked. Eating is their primarily job. And if you’re wondering if such a cow ever runs out of rumen contents, your arm is your gauge.
Finding yourself digging deep? Just offer her more hay. Her rumen levels should be up by the next morning. And as for accidentally spreading “bad” gut microbes, it’s all in numbers. The vast majority of gut microbes in a healthy cow are good, keeping the bad ones in check.
Another amazing thing about fistulated cows is that their ingesta can be used to help other ruminant species, too. Goats and sheep in need of some microbial boosts for their guts can take a dose or two from a fistulated cow. Sick alpacas and llamas can benefit as well. One fistulated cow in a geographical area often ends up helping animals from different counties and sometimes even different states.
This article originally appeared in the January/February 2022 issue of Hobby Farms magazine.