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Getting the Timing Right with Ear Technology

Judging when a cow is on heat and whether she is at the optimum point for artificial insemination is a lot easier these days with the help of technology relaying information from an ear tag.

Dairy farmers using technology talk of lower empty rates, higher six-week in-calf rates, more replacements, saleable stock, and less bobby wastage. Kaylene and Bill Aubrey have been using CowManager for the past four matings on their 300-cow herd near Tirau in the Waikato, New Zealand.

Right Timing, Right Cow

Kaylene and Bill have recently bought another property to milk another 230 cows and factored the cost of the technology into the purchase because they want to use it for those cows as well. Kaylene is also an artificial breeding (AB) technician. “We looked at other technology several years ago before settling on the ear tags because they were unobtrusive for the cows, which were already used to wearing ear tags.”

The empty rate in their three-year-old cows was 2% this year and the rest of the herd has been between 6% and 9% for the past two seasons. At this season’s mating, they used sexed semen for more replacements, then used dairy beef semen including Charolais followed by shorter-gestation Belgian Blue so that they had no bulls. Instead of bobbies, they had sought-after beef breeds to sell.

For the sexed semen, Kaylene says it is so important to get the timing right and the technology gives them continuous updates so they know exactly how many hours a cow is on heat so they can inseminate exactly when they want. Kaylene: “It’s all about optimising the straws you have by getting the timing right and the right cows.”

It also gives them information such as when the cow last cycled, how strong the heat is and a pattern of irregular cycles that may highlight ovarian problems.

Accuracy is Key

CowManager ear tag technology gathers information through its ear sensor on fertility as well as health and nutrition. For mating, it has a 98% accuracy for predicting a cow’s heat, based on the information it collects from the cow such as its level of activity, rumination and eating. About 250 New Zealand farmers now use the ear tag technology which has had algorithms developed for different environments including South Island versus the North Island to better use the information.

Jared Bekhuis, general manager of local CowManager distributor Senztag, says a big plus for the technology is the live repeaters that send information to a smartphone or device 24/7. That means farmers can see a cow in the early stages of heats in the morning and plan ahead for the best time to inseminate her.

“CowManager in New Zealand have averaged an 8% increase in their six-week in-calf rate and a 5% decrease in their empty rate. Most of those farmers no longer use bulls, are breeding more replacements to keep or sell, often via sexed semen, and putting fewer or no bobbies on the truck”, Bekhuis says.

“We Wouldn’t Be Without It”

Kaylene says the technology is displayed via graphs and colours which makes it quick and easy to understand what is happening out in the paddock. Cows coming into heat show up as light blue, moving to light green as the heat progresses and finally dark green when they are fully on heat and ready to inseminate.

“It’s really good for heifers which sometimes only display heat characteristics for a few hours and those that are shy or don’t want to be dominated. We wouldn’t be without it and have a lot of people come and look at the system.”

The farm is not entirely flat, so they now have six repeaters spread around the paddocks to capture information from cows in every corner and hollow.

As technology pinpoints the optimum time to inseminate cows, Kaylene says the challenge now is having enough AB technicians to visit farms more regularly to get those cows at the right time and thereby improve mating results across the industry.


For more information, and to get in touch with a local representative from Senztag, check out