A Jersey X cow called Portia has been living with a window in her stomach since 2002 at Tufts University in the US.

So what is the point of the window, or fistulated stomach as it is called, in Portia’s stomach? It is so vets can study how cows digest their food.

Also scientists have learned what and how to feed animals so they get all the nutrients they need.

In the video below a vet from the Cummings School of Veterinary Medicine demonstates taking a sample from the fistulated cow.

“Cows and other ruminants; sheep, goats and lamas, they have what’s called a ruminant digestive tract and it has four chambers in their stomach, the first of which is the rumen.

“The rumen has all the bugs and bacteria, the good bugs, that are needed to digest the hay and other material that they eat which we cant digest.

So what happens is we get sick ruminants in our hospital who haven’t been eating for a couple of days and all of their bugs in their rumen die and their digestive tract basically shuts down.

“Without all those bugs they cant digest any of their food, even if they eat its not going to get digested too well,” the vet explains.

Samples taken from a fistulated cow can be tested in a lab to identify digestion rates of different diets.

Researchers can also put different feed types into the rumen and examine the time needed for the cow to digest that type of food.

Taking a sample

Portia’s fistulated stomach is normally covered and sealed well, so to take samples they take off the cover and and can get rumen samples from her, she says.

“The rumen samples have all the bugs that are necessary to keep the other sick animals digestive tracts going.

“So we reach in nice and deep here so we can get a good sample. Down towards the bottom is more fluid than the top, the top is more fibrous material because it floats.

We reach in and grab some and we take this bucket and strainer here and we squeeze off all of the juices into the strainer and through the bucket.

Depending on the animal you’re doing this with, normally you want to fill up about half a bucket or a bucket of a sample from the animal, she says.

“The actual process is called a ‘transfaunation’; we’re taking the fauna from her stomach and putting it into another animals stomach.

“We take the juices that we get, which are at the bottom of the bucket, and we take a feeding tube and we go into the hospital and we pass the feeding tube into the sick animal,” she says.

As well as the juices she explains that sometimes alfalfa pellets are added to give a jump-start to their digestive tract.


The cows fistula was done as a standing surgery in 2002 with local anaesthetic, some antibiotics and some pain medication, she says.

“The scar tissue forms around it, there’s really no nerve endings there so she doesn’t feel the fistula in her.

It doesn’t make her sick its not going to change her life expectancy, doesn’t really need any maintenance, the only thing we do is clean off the stuff that seeps out the bottom.