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.
It is possible to know the exact hour a cow comes on heat so farmers can time AI to achieve optimal results. They can buy sexed semen with more confidence of success because they know exactly when to inseminate a cow and they can pick up those cows with silent heats or those with problems that need to be resolved before they can get in-calf.
Dairy farmers using technology talk of lower empty rates, higher six-week in-calf rates, more replacements, saleable stock, and less bobby wastage.
Senztag’s CowManager monitoring system uses ear tag technology which 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 farmers around the country now use the ear tag technology which has had algorithms developed for New Zealand’s different environments including South Island versus the North Island to better use the information.
General manager, Jared Bekhuis, 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.
He says farmers using CowManager in NZ 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.
Kaylene and Bill Aubrey have been using CowManager for the past four matings on their 300-cow herd near Tirau in the Waikato. They 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 and says they 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, she 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.
“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.
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.
