Automated Heat Detection

Heat Detection Cow

When detection of estrus is based only on the observation of standing heat, two or three observation periods of 30 minutes per day typically detect no more than 12–19% of cows in heat1.

Reproduction monitoring solutions eliminate the guesswork and inconsistency of evaluating the reproductive status of every individual heifer and cow. The technology empowers dairy farmers to optimize conception rates, while reducing skilled labor requirements and saving time. Leveraging behavior monitoring based on activity, rumination, eating and other key cow behaviors, the reproduction monitoring applications provide unmatched heat detection accuracy, including detection of weak heat signs, while minimizing false positives. They deliver actionable insight in real time, with precise insemination timing guidance. Using reproduction monitoring solutions, dairy farmers can reduce the calving interval, while optimizing the use of reproductive hormones. With fewer days open, farmers can improve milk production as well as the genetic quality of their herd.

One of the most powerful solutions available is provided by Allflex Livestock Intelligence monitoring solutions. The Allflex reproduction monitoring applications use collar and ear tags for reproduction and health monitoring. Their system, based in activity and rumination monitoring provide farmers with Cows in Heat (estrus), Cows with Irregular Heat, Suspected for Abortion, and Anestrus Cows reports.

Example of Allflex farm configuration

Heat Detection Cow

The vast majority of cows in estrus will have a drop in their rumination level2. The Allflex Heat Index uses this rumination information in the calculation of the cow’s individual heat index, thus improving on the efficiency of heat detection based on activity levels alone. The next figure displays the typical relationship between rumination and activity on the day of estrus.

Allfex heat detection

The heat detection accuracy of Allflex heat detection and reproduction monitoring solutions is around 90-95%.

Other Solutions for Heat Detection

Camera-software systems

All estrus behaviors, in addition to standing heat, can be video-recorded. The rate of detection may reach 74–90% with three daily visual observation periods of 30 minutes or more. A camera-software system has been recently designed in France4.

Body temperature measurement systems

Automated systems for body temperature measurement that feature radiotelemetric transmission are currently used for calving detection, but still require validation for use in estrus detection (cows in estrus have increased body temperature). Some devices are ingested as a bolus and measure the temperature in the reticulum. Other devices are placed in the vagina.

Automated milk progesterone measurement

Prostaglandin F2α is released in the non-pregnant cow from day 18 post ovulation, leading to a drop in the blood concentration of progesterone (P4) preceding a new ovulation. This drop also occurs in milk. Therefore, measuring progesterone in milk can predict estrus. A fully automated system of P4 assay in milk has been recently marketed in Europe5.

Why farmers should change to automated estrus detection systems

Farmers can use technology to optimize heat detection and achieve high conception rates in their herds. This means:

  • Catch accurately which cows are in heats and minimize false-positives. Systems that combine movement intensity detection and rumination recording, recognize heat-related behavior patterns (excluding truly silent heat) and deliver high heat detection accuracy.
  • Get heat reports in real-time. Systems that transmit information a few times per hour from the cow’s tags to the terminal allow for the perfect timing for AI.
Allfex heat detection


  1. Roelofs J, Lopez-Gatius F, Hunter RH, vanEerdenburg FJ, Hanzen C. 2010: When is a cow in oestrus? Clinical and practical aspects Theriogenology 74, 327–344.
  2. Stangaferro, M. L., R. Wijma, L. S. Caixeta, M. A. Al-Abri, and J. O. Giordano. 2016. Use of rumination and activity monitoring for the identification of dairy cows with health disorders: Part I. Metabolic and digestive disorders J. Dairy Sci. 99:1-16.
  3. Saint-Dizier, Marie & Chastant-Maillard, Sylvie. (2012). Towards an Automated Detection of Oestrus in Dairy Cattle. Reproduction in domestic animals = Zuchthygiene. 47. 10.1111/j.1439-0531.2011.01971.x.
  4. Hétreau T, Giroud O, Ponsart C, Gatien J,Paccard P, Badinand F, Bruyère P. 2010. Simplifier la détection des chaleurs desvaches laitières grâce à la vidéosurveil-lance : une étude dans les races Mont-éliarde et Abondance. Renc RechRuminants 17, 141–144.
  5. Asmussen T, 2010: Herd navigator or "How to benefit from frequent measurements". Proc ICAR 37th Annual Meeting- Riga, Latvia, 31 mai-4 juin 2010,291–293.
  6. Morton J.2011. Guide to automated heat detection technologies. InCalf Data Fertility Project 2011, Dairy Australia, pp. 60-61