Karl Klessig, whose family has a dairy farm and cheese-making business in eastern Wisconsin, describes it as a kind of natural family planning system for bovines.
Activity tracking systems have been available for decades, but interest in them has grown as the technology becomes more accurate and easier to use. The collars don't eliminate the use of hormones because some cows, like some people, have difficulty getting pregnant, but farmers said the systems reduce drug use, help cut labor costs and provide an added benefit early warnings of illness.
The collars are designed for and almost exclusively used by dairy farmers who must keep cows pregnant to keep the milk flowing. If the animals don't give birth about once a year, their milk will dry up, similar to a woman who stops breastfeeding. Cows then cost more to feed than they earn, and eventually, they're sold for slaughter.
Klessig's family was among the first in the U.S. to invest three years ago in a system sold by Israel-based SCR. Their collars carry motion detectors and microphones that pick up the sound of chewing, which reflects digestion. Cows leaving the milking parlor go through a gate where the electronic boxes on their collars are scanned. The gate sends cows in heat in one direction and the rest in another. A vet comes to the farm each morning to breed the animals that are ready.
"For us, with our cheese factory, we want to be as wholesome and natural as we can be," said Klessig, whose family milks 550 cows in Cleveland, Wis.
Successful breeding usually involves artificial insemination within a matter of hours after cows ovulate. Some farms use a combination of hormones to induce ovulation so the cows can be bred at the right moment. Others have workers watch cows for signs of heat; monitoring systems are a labor-saving alternative.
Stephen LeBlanc, an associate professor at the Ontario Veterinary College, said during the recent World Dairy Expo in Madison that the attraction of a monitoring system is that farms that don't want to use hormones don't need as many workers to watch the cows.
"There's really no public health threat at all from the hormones that are used in cows for managing reproduction," LeBlanc said. "Nevertheless, it's absolutely appealing to producers to not need to employ that tool. It's more pleasant for them; it's more pleasant for the cows."
There are no totals for how many dairy farms use activity monitoring because most companies don't release sales. But Tom Breunig, SCR's general manager in the U.S., said 2 million cows worldwide wore his company's collars at the end of last year, and that number was expected to double in two years.
Activity monitoring doesn't work on all cows because some don't show signs of heat, and others may not ovulate at all without a hormonal boost. Klessig said it has been effective with 95 percent of his herd well above the 70 percent that Paul Fricke, a University of Wisconsin-Madison dairy science professor, said is typical.
Dejno Acres in Independence, Wis., has used activity monitors for 15 years, but it bought a new system two and a half years ago that provides more accurate, timely information and is easier to use, herd manager Monica Dejno said.
Older systems were essentially pedometers that counted cows' steps. Newer ones track three-dimensional motion, catching turns and other horizontal movements the earlier technology may have missed. Some collars, like the ones Dejno's family bought from the Swedish company DeLaval, transmit data wirelessly every hour, and new software converts the data into easy-to-read graphs.
Unbehaun Acres near Richland Center switched from a hormone program to activity monitoring last year, paying $18,000 for a system that covers 220 cows.
Herd manager Lucas Unbehaun said his farm has cut its drug costs and increased its conception rate, but he's been even more impressed by the system's ability to flag a drop in activity, which is an early sign of illness.
"We would have eventually have noticed that (the cow) was ill, but the system shows you a lot faster," Unbehaun said, adding, "I think for us, it's made a vast improvement and will hopefully continue to do so."