Disappointing mating results two seasons ago has seen Stratford sharemilkers Becky Corlett and David Knowles take a more technical approach which is driving down their empty rate and providing peace of mind.

After their empty rate climbed to 16% they knew they had to make a change.

“We were all upset with that result. It was a really tough season for us. It was bad weather wise, and it seemed our cows just weren’t coming onto heat or we were missing them,” Becky says.

The couple sharemilk 600 cows on David’s parents’ 230-hectare Taranaki farm, DAK Dairying. They know the success of their business comes down to getting as many of their cows in calf as possible.

So the couple, who had been using scratch pads and tail paint, decided to invest in a better system and looked around at alternatives.

A neighbour down the road had been using Flashmate electronic heat detector pads on some of his herd so the couple decided to give them a try.

“The investment was worth it. We had a 5% decrease in our empty rate, so we went down to just below 11%. That means less cull cows, hopefully more replacement calves and also means a shorter calving period, as we have a lot of cows due within the first six weeks,” Becky says.

“For us just the drop in the empty rate is enough to pay for itself. At 4am, when you’re tired it’s pretty hard to miss a red flashing light. FlashMate means you’re not having to read a scratch pad. You still need a level of skill in reading a cow, but with the flashing units, 90% of the job is done for you.”

“There were days when we were putting up 50 cows for AI and that’s just unheard of for us. The AI tech was saying they’re all on heat. They’re not false ones.”

Because Flashmate monitors animal contact to pick up when a cow’s on heat, Becky says it can pick up the ‘silent cows’ because it recognises mating signals.

The unit looks for specific patterns of animal contact associated with mating activity, such as frequency, number and length of contacts, but it will not be activated by a one-off contact event.

“With scratch pads it’s not always easy to select the right cows on heat and it’s not reading all those silent cows.”

The Flashmate unit flashes red for 26 hours once the right heat activity is detected to indicate the cow is ready for artificial insemination.

Once artificially inseminated, if the same cow does not come back on heat within 25 days, it will flash green to indicate possible conception. If the same cow returns to heat again, the unit will again flash red.


  • Get rid of excess hair with a curry comb two days before applying the unit, allowing the pads to stick close to the skin.
  • Give the glue time to get tacky – Becky recommends spraying glue on as the cows enter the rotary shed and applying the pads just before exiting.
  • Apply to left rump. “They’re easy to see as it’s facing us as they’re coming around the rotary platform. There is a big red light flashing at you. They’re pretty hard to miss, even for our more inexperienced staff.”