A Cal Poly dairy science student has spent the past year researching new technology that’s meant to help increase cow pregnancy rates — a senior project that his professor called one of the most interesting and impactful in recent years.

Trevor Nutcher, 21, did a project that involved attaching a new activity monitor device to the necks of more than 100 cows on campus.

The electronic collars monitor behavior such as movement, chewing and bellowing to best determine when cows are in heat so dairy science students can more successfully use artificial insemination to impregnate the animals.

The devices use a microphone to record the data — the sounds of chewing and other noises.

Nutcher said his study of the monitors, donated to the university by the Texas-based company Micro Dairy Logic, enabled him and other students to better determine when a cow was most likely to effectively breed.

Other companies produce similar products, but the prevalence of their use in the industry isn’t widespread, Nutcher said.

“Basically, you have to carefully observe a cow to know when she’s in heat,” he said. “The idea with this technology is to provide data so you don’t have to spend as much time watching them.”

The devices transmit data to a computer program when the cows pass through a scanner that reads the information. Each device costs about $100.

Without such a collar, Nutcher said, one common method for determining the 12-hour window during which cows are most likely to get pregnant every 21 days is to observe them for increased activity and movement.

Another is to see whether chalk that is put on their backs is rubbed off, because cows instinctively mount each other when in heat.

On a busy farm, dairy workers don’t always have time to observe each cow carefully, so they may miss the window that’s ideal for breeding.

Some farms also synchronize the ovulations of cows using shots of protein hormones or other types of injections that make them cycle at roughly the same time.

Cal Poly has about 230 cows on campus. The new devices will make it easier for student workers to monitor whether the cows are sick (by recording chewing habits) and when to breed, as well as determine whether cows are pregnant.

Nutcher said the system improved breeding on campus from a 14 percent pregnancy rate to a 22.5 percent rate in the first five months of use.

He believes the system has continued to maintain a pregnancy rate in the 25 percent range, though he lacked the latest data.

“This is one of the best projects we’ve done in a long time,” said Stan Henderson, a Cal Poly dairy science professor and Nutcher’s adviser.

The school plans to keep using the activity monitoring devices, he said.