Cannulated steer

This cannulated steer named Bo has a plug-like object that allows agriculture students to observe the digestion of his food.

You all know that there is whole milk that comes from whole cows, but what about cows with holes in them?

At Missouri State University, the students in the William H. Darr School of Agriculture get to experience these “holey” cows first hand.

Cannulated cows are cattle that have been surgically fitted with a porthole device that allows access to the rumen; the largest compartment in the cow’s stomach.

The cannulated cattle, or cattle that have been surgically fitted with a porthole-like device, at the Darr Agricultural Center are part of a research program that observes the effects of various types of distiller dried grain on the cattle’s performance. The students in the department observe how feeding the steer different levels of DDG can affect hay intake, digestion and methane production.

Melissa Hudson, assistant professor of animal science, said the idea of cannulating animals, such as cattle, came about when a soldier in the Civil War was shot in the side. The bullet wound would not heal properly and ended up forming a permanent fistula, an opening, to the soldier’s stomach.

A doctor on sight discovered the soldier’s fistula and started to research the way the soldier was digesting his food.

The research learned from the cannulated cows can help educate farmers about the best types of grain to feed their cattle in order for them to perform at their highest level.

The program started in the fall of 2011. Since then, more than 250 Missouri State students have worked with the cannulated cattle.

There are four cannulated steers at the Darr Agricultural Center. They each have a first name that was hand-picked for each of them and are treated like kings of the castle.

“Beau, Bob, Hank and Goggles have the easiest and best job out of all the steers on the ranch,” Hudson said.

The cows had a surgery performed on them at the age of two or three in which a four-inch fistula was cut into the left-hand side of the cow to allow access to the rumen.

Once the fistula is made, it is fitted with a cannula, a plug-like object, to protect the hole from the outside world. The surgery takes about an hour, and the cows are anesthetized so they don’t experience any pain.

Cows have four compartments in their stomach, with the largest being the rumen, where most of the animals’ digestion occurs. The digestion of the food and nutrients is done by billions of microorganisms that also keep the cow healthy.

It’s not all work and no play at Darr Ranch, though. Hudson said there is a day when students get to come in with any food items, ranging from Snickers bars to Twinkies. Students get to place these food items inside the steer and observe how long it takes for the cow to digest each of the items.

The fistula does not affect the welfare of the steer. They still take in food orally and live life practically the same as the other steers on the ranch. They do not feel pain when students insert their arms into the rumen to add or remove material. The removing of material, such as hay and grain, also does not impact the cow because it can eat more food to replace whatever was removed.

If you want to find more information on the research being done with the cannulated cows at Missouri State, you can contact the William H. Darr School of Agriculture. You call them at (417) 836- 5638, email them at or you can go by their office location at Karls Hall 201.