TDK conference 2021

Our research was carried out in a Holstein-Friesian dairy farm of the Arany-Tej Kft in Nagykőrös. In this farm, nearly 300 animals are milked twice daily. Our sample was based on 95 animals, that were showing a completely healthy general condition. During the study we used two different estrus monitoring systems and 3 different ov-synch based hormone protocols on the animals. The hormones were used to artificially synchronize the ovaries and thus induce estrus. The two types of estrus monitoring systems used were a foot-mounted pedometer and a Kamar QuickStick Heatmount detector, which was placed on the tail. Both were used to detect the onset of estrus symptoms. The cows were divided into 3 groups according to the hormonal product used. Ov-synch is based on the correct use of alternating gonadotropin and prostaglandin hormones.

The first group consisted of cows with a short program (P1). Here, the Kamar system detected symptoms and signalled in 56.1% of the cases and the Nedap system in 53.6% of the cases. In 48.7% of the cases both systems signalled and in 39% neither of them.

The second group consisted of cows with a longer program (P2). In this group, with the Kamar system we could detect symptoms in 51.6% of the animals, whereas with the Nedap in 38.7%. Both systems detected symptoms in 35.5% of the animals, and neither in 45.1%.

Despite the fact, that real visible symptoms were only seen in 67% of the animals studied, but trusting the effect of the hormones, those cows were also inseminated where none of the devices showed any signs of estrus. The two estrus monitoring systems were able to detect and signal estrus in almost the same percentage, the difference between the two is not significant.

The third group consisted of animals not treated with any hormone (P0), thus relying on the natural cycle of the ovary. In this group, the Kamar system signalled in 95.6% of the cases, the Nedap in 91.3%, both in 91.3%, and neither in 4.3%. Cows with spontaneous estrus showed more pronounced estrus symptoms than the ones in the hormone-treated groups.

The pregnancy rate of the experimental group was 63.16%. This broken down by group looks to be P0 91.3%, P1 58.53%, P2 48.39%.