“Cannulated cows are the same as all other cows in the herd except that they are fitted with an item called a cannula,” said Natasha Weaver, a senior in animal science. “Basically, the animals have surgery performed upon them that creates a passageway in the side of the animal so researchers can perform readings on what takes place in the cow’s rumen.”
Cows have four compartments in their stomach with the largest being the rumen. This cavity is the focus of operation for the research with cannulated cows.
The rumen is the part of the stomach where the majority of the animal’s digestion occurs, which is what researchers are trying to learn more about. Cows typically consume 50 pounds of foliage per day, and this food sometimes does not provide the best possible nutrient values for the animals
“We have had an emphasis on nutrition for years because of its importance in regards to milk production,” said Maurice Eastridge, professor of dairy nutrition. “By researching what nutrients the cows receive from various feed combinations, we are hoping to improve nutrition recommendations for dairy producers and the livestock industry in general.”
The digestion of food for nutrients in the rumen is done by millions of microorganisms. The abundance of microbes also keeps the cannulated cow healthy, often the healthiest in the herd, Weaver said.
“You would think that by having an opening in their sides would allow outside microbes to enter and infect the cows, but with there being such a numerous presence of natural microbes already in the rumen, the new microbes cannot compete for nutrients to survive,” Weaver said.
Because these cows are so healthy, some farmers keep a cannulated cow on the farm to help improve the health of the other animals in the herd.
“Basically, the cannulated cows serve as a rumen fluid donor to sick animals. This is done by extracting rumen fluid contents from the cannulated cow and feeding it to the sick cow,” Eastridge said. “The microorganisms in the fluid multiply and take the place of the bad organisms in the sick cow and make the cow healthy again.”