Hole-y cow! How farmers are monitoring what cows eat using ‘window’ in their sides

Farmers have a wealth of technology and data at their fingertips to get the best from livestock, but one old-fashioned technique still remains. Researchers have fitted cows with cannulas in their sides, that are cut directly into the animal’s digestive tract. The 8-inch (20cm) holes allow farmers to directly see how food is being processed, and are plugged using rubber stoppers when not being used.

Once the cannula is surgically placed in the cow, the animals grazes for a set period of time before being examined. Farmers remove the plug and pull the grass and oat mixture from the rumen. This material is collected and tested, and this analysis shows farmers and researches which forages get the best results from the livestock, based on how much is digested. The practice is said to have become common place in the 1920s but reports of cows being used in this way for scientific research date back to 1833. Cows with cannulas fitted are also known as fistulated cows.

Farmers and researchers claim the process can help the environment by improving the energy efficiency of cows, which in turn reduces the amount of methane they produce. The cows are anaesthetised during the surgical procedure and are said to experience no pain when being examined. But animal rights campaigners claim it is abuse, and have branded the practice as cruel. An episode of Ripley’s Believe it or Not interviewed Dr. Edward DePeters from the University of California Davis. The report claimed fistulated cows have a longer life span due to the care they are given.