A fistulated cow is a cow with an intentional hole in it for scientific research. In 1822, a Canadian suffered a wound that refused to heal, but the man otherwise was in fine health. His doctor discovered that the digestive process could be observed directly through the hole. The discovery spread, and for over 150 years, fistulation has been used to observe digestive processes in living animals, with the first recorded scientific use on animals dating to 1833.

In modern days, scientists install a plastic device called a 'cannula' into the side or stomach of an animal which allows them access to the various organs. In the case of the Davis fistulated cows, they observe how fast the cow digests various foods and what chemical/biological processes the food undergoes. Visit the Cole Facility on Picnic Day to learn more about UCDavis' fistulated cows.

This GeoCities website has a picture of a fistulated cow.

Ripley's Believe it or Not

The television series of Ripley's Believe it or Not did a segment on the fistulated cows in Davis. They interviewed Dr. Edward DePeters and ran through the entire process, showing each UC Davis facility used for each step. As a ending point, they note that the cows have a longer life span due to the care extended to them as experimental animals.

  • Longer life span than what? For all practical purposes, a cow's lifespan is determined by economic factors, with a beef cow being slaughtered at 18 months and a dairy cow at 4 years. Comparisons with the natural lifetime of a cow are hardly relevent as virtually all cows are raised for production of meat and/or milk. —Grumpyoldgeek

Dr. Edward DePeters reaches deep into the cow to pull out partially digested grass. (Image from Ripley's Believe it or Not) Displaying the results of the extraction. (Image from Ripley's Believe it or Not)

What's Christmas Without a Fistulated Cow?

Right up there with holiday characters like Santa and Rudolph is, of course, the fistulated cow.

Picnic Day

A cow used to be brought to Picnic Day. There is an online petition to bring it back.


Copyright Note: All above images were used without permission and the original author could not be contacted.

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When I was really young, at picnic day I got to pull some grass out of the fistulated cow! —StevenDaubert

Question: Where can one find the fistulated cows? Is there a field somewhere that they wander about? I have a guest in town who is curious. — M

I saw one in the enclosure west of Dairy Road (by Tercero South) on my way to Health Sciences District just this past Tuesday. (I thought it was a mutation at first till I stumbled upon this page by chance via Recent Changes.) Your mileage may vary though; I don't know the cow's grazing hours, and I can't say if those particular cows are always present. —EBT

2010-05-14 18:06:20   I believe a similar device is also used to treat cows that are bloated. —jlc1988