A University of Arkansas graduate student recently found a new use for an old tool.
Tom Devine was conducting research into the influence of growth-promoting implants on the growth, estrus behavior and pregnancy rates of beef heifers. In order to determine the best time to artificially inseminate the heifers, Devine needed to record parameters like the time of onset and length of estrus, and the time, number and duration of mounts. So he turned to orange pads that attach to the backs of the cows – part of a system called HeatWatch.
One of the professors overseeing Devine’s study, University of Arkansas animal scientist Rick Rorie, has been using HeatWatch for 20 years. “We were using HeatWatch because it allows you to monitor animals 24 hours a day, seven days a week,” Dr. Rorie told Ozarks Farm & Neighbor. “HeatWatch allows you to never miss an animal in heat.”
The company that manufactures the system is now known as CowChips LLC, and recently released a second-generation product, HeatWatch II.
The system measures precisely when a cow enters heat, and Rorie said it’s been particularly valuable in the embryo transfer industry. He explained, “When you transfer an embryo from a donor to a recipient, the closer they are at the exact same stage of their reproductive cycles the more likely the embryo is going to survive a tough pregnancy. If we know exactly when a donor comes into estrus and exactly when all the recipients come into estrus, we can pick out the recipients that match her really well and have better pregnancy rates that way.”
The system is both high tech and simple. A transmitter mounted on the cow’s rump sends a signal to a radio receiver that records every time the cow is mounted; in addition to the time and duration of the mount it provides standing and suspect heat lists, and the status of the transmitter. The orange pad is attached along with the transmitter box to a patch. The cattle have to be within 400 meters of the radio receiver with no obstructions, or within 6.4 kilometers of a repeater that retransmits the signal; the data are stored in a buffer that can be no more than 150 meters from the receiver.
The system is not cheap; Rorie said it costs $3,000-4,000, with transmitters running $50-60 apiece, and $5 or $6 for the patches. Any functional computer can be used to run the software. There are also competing systems; one similar to HeatWatch will be offered by Estrotect and called Accubreed, but it’s not yet on the market. Another less expensive stand-alone mount detector is the TattleTale, available through Microdyne Co., LLC.
Rorie said HeatWatch is much more efficient than attempting visual observation. He said, “If you just go out and watch a herd of cows for estrus so you know when to inseminate them, just by watching them a couple of times a day you might detect 50-60 percent of them when they come in… HeatWatch will get your efficiencies up there, probably, to 90-95 percent.” And it makes better use of a rancher’s time; rather than watching the animals in the pasture, the rancher can just download the information a couple of times a day.
And Rorie noted the patches can just be left on the cows. “If the animals don’t become pregnant through artificial insemination, roughly 21 days later they’ll be back into estrus,” he said. “So if you leave the system on them, you can see which ones didn’t take the artificial insemination, see when they come back into estrus and inseminate them a second time.”
