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Estrus detection in dairy cattle: changes after the introduction of an automated activity monitoring system?

Original Article
Estrus detection in dairy cattle: Changes
after the introduction of an automated
activity monitoring system?*
I. Michaelis1; E. Hasenpusch2; W. Heuwieser1
1Clinic for Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany; 2Rinderzucht Schleswig-Holstein eG, Neumünster, Germany
Key words
Activity monitoring, dairy cattle, accelerometer, estrus detection Aktivitätsüberwachung, Milchvieh, Beschleunigungsmesser, Brunst -erkennung Zusammenfassung
Objective: In context of the study farmers using an automated activ-
Gegenstand und Ziel: Es wurden Landwirte befragt, die zur Brunst -
ity monitoring (AAM) system called Heatime were surveyed on estrus erkennung ein automatisches System zur Aktivitätsüberwachung der
detection practices. The aim of the study was to gain an overview of Kühe (Heatime System) nutzen. Ziel der Studie war, einen Überblick
the usual estrus detection methods and especially to learn about the über die üblichen Brunsterkennungsmethoden zu erlangen und insbe-
practical aspects of that system. Material and methods: Items ad-
sondere Informationen über die praktischen Aspekte des genannten dressing farm and animal environment, estrus detection before and Systems zu erfahren. Material und Methoden: Über einen Frage-
after installation of Heatime, reproduction, Heatime management and bogen wurden allgemeine Daten zum Betrieb, zur Umwelt der Tiere,
the far mer’s perception of efficiency were asked. Results: A total of Reproduktion, Brunsterkennung vor und nach Installation des Heatime
232 survey forms were returned (58.3% response rate) and 219 sur-
Systems, zum Management des Heatime Systems und die Meinung veys could be used for final analysis. Visual observation was the most der Landwirte über dessen Effizienz abgefragt. Ergebnisse: Von den
common practice to detect estrus. After installation of the Heatime 232 zurückgesendeten Fragebögen (Rücksendungsrate von 58,3%)
system the farmers assessed that the application of hormones for re-
konnten 219 für die Auswertungen genutzt werden. Die direkte Be - production management decreased. The majority of the responding obachtung war die meist genutzte Methode, um Kühe in Brunst zu er-
dairy farmers (93.1%) strongly agreed or agreed that heat detection kennen. Nach der Installation des Heatime Systems reduzierte sich
was higher after the installation of Heatime. Most of them (92.3%) nach Einschätzung der Landwirte die Applikation von Hormonen zur
strongly agreed or agreed with the statement that the reproduction Brunstinduktion. Die Mehrheit der Landwirte (93,1%) stimmte voll
management became easier with Heatime. Conclusion: Overall, und ganz zu oder stimmte zu, dass die Brunsterkennungsrate nach der
94.1% of the responding farm managers were satisfied with the Hea-
Installation des Heatime Systems höher war. Die meisten Befragten time system and almost all of them (94.5%) would install the system (92,3%) stimmten voll und ganz zu oder stimmten zu, dass das Repro-
again. Clinical relevance: The results show that the Heatime system duktionsmanagement einfacher wurde. Schlussfolgerung: Insges-
is a well accepted estrus detection aid and has the potential to reduce amt waren 94,1% der befragten Landwirte zufrieden mit dem Hea-
the time needed for estrus detection and might potentially reduce the time System und 94,5% würden ein solches System wieder installie -
use of hormones.
ren. Klinische Relevanz: Die Studie zeigt, dass Heatime ein akzep-
tiertes elektronisches Hilfsmittel zur Brunsterkennung ist. Dieses Sys-
tem hat das Potenzial, die für die Brunsterkennung erforderliche Zeit
zu reduzieren und den Einsatz von Hormonen zu vermindern.
Correspondence to
Brunsterkennung bei Milchkühen: Veränderungen nach der Einführung eines
automatisierten, aktivitätsmessenden Brunsterkennungssystems?
Tierärztl Prax 2013; 41 (G): 159–165
Königsweg 65D-14163 BerlinEmail: * Herrn Prof. Dr. Dr. h.c. mult. H. Bostedt zum 75. Geburtstag gewidmet.
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I. Michaelis et al.: Estrus detection practices in cattle
validated (1, 4, 5). It is wel documented that activity of cows in- creases considerably during estrus (16, 28, 34). This observation Reproductive efficiency remains of major importance for the dairy has been utilized in different applications. Activity meters such as industry (17, 26). Senger (29) described the poor detection of pedometers or accelerometers for automated estrus detection have estrus as the most important problem, which is limiting high been reported as useful (15). A further approach were milk pro- reproductive efficiency. Several risk factors such as milk yield, gesterone tests, which were commercialized to detect non-luteal lameness, poor nutrition, and herd size have been identified to af- periods and to indicate estrus detection errors (19). While high fect reproductive performance (22). Estrus detection efficiency concentrations of progesterone indicate interestrus low concen- has the highest correlation with the calving to conception inter- trations are not necessarily indicative of estrus. Furthermore, the val and the greatest impact on reproductive performance (2, 8). progesterone concentration in milk is highly correlated with the The average estrus detection rate in dairy herds ranges widely milk fat content (i. e. low before milking, high after milking) which from approximately 50% to 92% (9, 18). Recently, it has been de - makes the assessment of the concentration more difficult (10, 13).
monstrated that today’s cows show fewer signs of estrus and for In the past years one AAM system (Heatime, SCR Engineers shorter duration. Mainly the durations and intensities of beha - Ltd., Netanya, Israel) has been promoted by several AI companies vioral signs are decreased in terms of reduced sniffing of the vulva and is increasingly used by the dairy industry. According to infor- and less mounting activity. Therefore it is more difficult for mation provided by the manufacturer and German artificial in- farmers to identify estrus (7). Some cows express signs of estrus for semination companies, about 1,700,000 Heatime tags have been less than 3 hours (24). It has been demonstrated that the average sold worldwide and approximately 100,000 tags are currently used estrus period lasts for about 9.5 hours during which the cow on more than 1000 dairy farms in Germany, respectively. The Hea- mounts other cows 10.1 times on average. Only six mounts lasted time system consists of animal tags, a smal control terminal and more than 2 seconds (31). These data il ustrate that the opportun- an identification (ID) transceiver. The animal tags monitor indi- ity to identify a cow in estrus is relatively short (i. e., 24.1 seconds vidual cow activity levels and 24 hour cumulated activity. Every animal movement and movement intensity is provided using a A variety of estrus detection aids such as heat mount detectors, three-dimensional accelerometer. The data is analyzed and filtered activity monitoring systems, and tail paint were developed and by using an algorithm in an on-board processing unit. The result is Survey question and answer categories
Herd size
All herds
tions related to farm and animal environ- Box stall
Deep straw bedding
What kind of material is used for the stall? Straw
Rubber mats
Early lactation cows
Late lactation cows
Dry cows
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I. Michaelis et al.: Estrus detection practices in cattle
a dimensionless activity index that is stored in 12 2-hour memory is not available. Therefore, the objective of this study was to ident- cel s. The neck col ar positions the logger on the left side of the ify current management practices related to estrus detection in neck. The ID transceiver should be located at a place were each Germany via a survey of dairy managers using the Heatime system cow passes trough at least twice a day. Suggestible locations are, for particularly considering factors that could influence estrus detec- example, above the exit from the milking parlor or over drinking tion efficiency.
stations. When a cow passes the ID transceiver data is sent via in- frared communication from the tag to the control terminal and over a possible connection to the farm computer (Heatime for PC, Material and methods
SCR Engineering Ltd., Netanya, Israel).
Most recently a direct comparison between pedometers (SAE A comprehensive survey form was developed to obtain informa- Afikim, Kibbutz Afikim, Israel), accelerometers (Heatime) and tion about common management practices related to estrus detec- heat mount detectors (Scratchcard, Dairymac, Hampshire, UK or tion from farmers using the Heatime AAM system. The survey KaMaR, Zionsvil e, USA) was conducted on one commercial UK was conducted in cooperation with two German semen sales com- dairy farm (14). The results based on 67 Holstein Friesian cows panies (Rinderproduktion Berlin-Brandenburg, Groß Kreutz; Rin- demonstrated a sensitivity of 58.9% for the accelerometers, 63.3% derzucht Schleswig-Holstein eG, Neumünster), which also support for the pedometers, 56.7% (KaMaR) and 35.9% for the heat mount the purchase of the Heatime system to their customers. The survey detectors (Scratchcard) compared to the concentration of milk form was delivered to the herd managers in March and April 2011 progesterone as the reference method. A true estrus was defined as by mail and was returned anonymously. any event identified as estrus by a given detection method that The questionnaire included a total of 49 questions related to coincided with a period of milk progesterone less than 0.3 ng/ml four sections; i.e. farm and animal environment (7 questions), es- fol owed by a period of milk progesterone more than 0.3 ng/ml. trus detection before and after instal ation of Heatime (14 ques- When two of these methods were combined the sensitivity in- tions), aspects about reproduction and Heatime management (10 creased up to 75.9% and the positive predictive value was 60.3%. questions), and the farmer’s perception of efficiency (18 ques- Data on specificity were not provided.
tions). The questions were open (10 questions), closed-ended (11 Current information about long term experiences and practices questions) or coded on a 5-point Likert scale (18 questions). Ques- how the Heatime system is being used on commercial dairy farms tions were analyzed by herd size, with herds categorized as smal Table 2 Summary of responses by herd managers (n = 219) to questions related to estrus detection before and after instal ation of Heatime system.
Tab. 2 Antworten von 219 Milcherzeugern zur Brunsterkennung vor und nach der Instal ation von Heatime
Survey question and
Herd size
answer categories
Small (n = 136)
Medium (n = 71)
Large (n = 12)
All herds (n = 219)
Visual observation
Visual observation
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I. Michaelis et al.: Estrus detection practices in cattle
(< 100 cows; n = 136), medium (100 to 199 cows; n = 71), or large forms most questions had been answered and these were used for (≥ 200 cows; n = 12) based on the number of cows. Percentages final analysis.
were rounded to the nearest whole percentage point. The data ▶ Table 1 provides the information from the first survey sec- were analyzed using IBM SPSS Statistics for Windows (Version tion regarding the farm and animal environment. Most of the re- 20.0, IBM Deutschland GmbH, Ehningen, Germany).
sponding farms (99.5%) had box stal s whereas 60.3% and 55.3% used straw and rubber mats as bedding material for the stal s, re- spectively. Access to pasture was provided by 79.0% of the farmers.
Results and discussion
In the second section of the survey, questions about estrus de- tection before and after the installation of Heatime were asked A total of 232 survey forms were returned in May and June 2011. (▶ Table 2). Before and after the Heatime system was instal ed al- That implies a 58.3% response rate, which is considerably high re- most every farm used visual observation to detect or to support garding other mail surveys (12, 33). Due to incomplete informa- detection of cows in estrus, respectively. The time spent on visual tion 13 forms (5.6%) were excluded. In the remaining 219 survey estrus detection decreased after the instal ation. It is wel known that the efficiency of estrus detection by visual observation Table 3 Summary of responses by herd managers (n = 219) to questions related to reproduction and management practices of Heatime system.
Tab. 3 Antworten von 219 Milcherzeugern zur Fruchtbarkeit und zur Anwendung von Heatime
Survey question and answer categories
Herd size
When do you attach the tags onto the cows? At calving
Days after calving
When confirmed pregnant
After the first AI
After the second AI
Whenever I need the tag for another cow
The data will be deleted after removing the tag How many hours after Heatime alert are the cows insemi- 10.7 ± 4.4 nated?Cows are checked for signs of estrus after Heatime alert How many cows are treated with PG for heat induction? How many days after calving are the cows inseminated? Who performs the artifcial insemination (AI)? Veterinarian
AI technician
Detected heats which are not used are documented SMS service is used to notice cows in heat Downloaded from on 2014-02-17 | IP: For personal or educational use only. No other uses without permission. All rights reserved.
I. Michaelis et al.: Estrus detection practices in cattle
requires experience, diligent at ention and time (11). Furthermore, the proper use of hormones does not have any known negative ef- the increasing herd size as wel as the increasing reliance on un- fect on animal welfare or public health, consumers are concerned skil ed labor turn estrus detection into a chal enge (6). Our survey about food safety and have a growing interest in animal health and data show that an automated system for estrus detection can help welfare issues especial y ethical concerns regarding the use of hor- mones and antibiotics (21). We speculate that such concerns wil Estrus detection in heifers through visual observation was less become increasingly important for the dairy industry and tech - common. Some of the farm managers (18.7%) answered that they nical aids besides hormones to assure proper reproductive per- used other aids to detect heifers in estrus. Almost all of them formance are beneficial and valuable to address those negative per- (92.7%) stated the use of a bul to service the heifers. ceptions. As most recently demonstrated (20) overal reproductive Heat mount detectors were used in only 7.3% and 1.4% of the performance was similar between management based on the auto- farms before and after Heatime installation, respectively. Ped- matic activity monitoring (AAM) system and a synchronization ometers (0.5%) and other devices (4.6%) were not commonly ap- program for timed artificial insemination (TAI). In some instances plied. In a similar survey with 153 large commercial dairy farms times to pregnancy was shorter with the AAM system. This com- located in the United States Caraviel o et al. (3) showed that only parison demonstrates that AAM systems might be an efficacious few herd managers used pedometers or pressure-activated rump- approach to reduce hormone use.
mounted patches to detect estrus. The reason might be a relatively Responses by herd managers to questions related to reproduc- low efficiency of those systems or a high loss rate. In a French tion and Heatime management are summarized in ▶ Table 3. On study efficiency and accuracy of an electronic device detecting average the responding farms had used the system for 9.8 ± 6.6 cows standing to be mounted (DEC system, IMV Technologies, (mean ± SD) months. Only 49.3% answered that they had a suffi- France) was evaluated (25). The study utilized 30 Holstein cows cient number of tags for their cows. The farms defined as small and demonstrated efficiencies of 35.4% (DEC system) and 68.8% had 67.9 ± 15.4 cows and used 31.7 ± 11.7 tags, which was con- sidered to be not enough by 53.7% of the farmers. The manufac- Regarding pedometry, Wangler et al. (32) described sensitivities turer recommends tags for only 40% of the herd if breeding is not between 73% and 95% depending on threshold values. In order to seasonal. More than 70.0% of the farmers checked the animals for have high sensitivities error rates between 54% and 80% had to be signs of estrus after an alert. The average interval from calving accepted. The results indicated that using pedometer data alone until first insemination was 64.3 ± 13.8 days. In 82.2% of the farms did not produce optimal results (32).
an artificial insemination (AI) technician conducted the insemi- The application of hormones for reproductive management nations.
decreased after the Heatime system was instal ed. About 6.8% of In the fourth section the farmer’s perception about the Heatime the responding dairy farmers completely stopped the use of hor- system was surveyed (▶ Table 4 and ▶ Table 5). The majority mones to induce estrus and 38.8% indicated that the hormone (93.1%) strongly agreed or agreed that estrus detection was higher usage was reduced since the instal ation of Heatime. Even though after the instal ation of Heatime. On their website the manufac- Table 4 Summary of responses by herd managers (n = 219) to questions related to the efficiency of Heatime system.
Tab. 4 Antworten von 219 Milcherzeugern zur Effizienz von Heatime
Survey question and answer
Level of agreement (%)
general is betterThe reproduction management is Downloaded from on 2014-02-17 | IP: For personal or educational use only. No other uses without permission. All rights reserved.
I. Michaelis et al.: Estrus detection practices in cattle
Table 5 Summary of responses by herd managers (n = 219) to questions related to satisfaction with the Heatime system.
Tab. 5 Antworten von 219 Milcherzeugern zur Zufriedenheit mit Heatime
Survey question and answer categories
Level of agreement (%)
Statement (n = 219)
I would have bought the system even without 27.4 support from the RSHI have enough information about Heatime I would like to use the system to early detect health issuesI am interested in a technical device to detect rumination activityI would like to use the system to monitor RSH = German semen sales company Rinderzucht Schleswig-Holstein eG turers advertise that the Heatime system improves fertility rates Overal , 94.1% of the responding farm managers were satisfied and calving cycles, reduces days open and reduces expenses on with the Heatime system and almost al of them (94.5%) would in- semen. More than half of the farmers (57.1%) strongly agreed or stal it again. It is noteworthy that 55.7% would not have bought agreed that the success of the insemination was better. However, the system without financial support of the semen sale companies. only 36.1% had the impression that reproduction performance im- As previously stated it is important that purchase and maintenance proved in general. These perceptions are in line with observations costs of an estrus detection system pay off (29). The majority of the that estrus detection aids can help to improve estrus detection respondents strongly agreed or agreed with the statement that the rates; but it wil take some time to see an improvement in fertility Heatime system was easy to handle (81.2%) and technical pro - parameters such as calving interval and insemination number blems were uncommon (86.3%). Heatime can be purchased as a (22). It is important to point out that these findings are based on a stand-alone unit, which does not require a computer or previous survey investigating personal perceptions. Further research is war- computer knowledge as the manufacturer describes. This might be ranted to validate our survey results with actual reproductive per- advantageous for smal farms without a computer. We speculate formance data. Most of the responding dairy farmers (92.3%) that a missing integration into an existing herd management soft- strongly agreed or agreed with the statement that the reproductive ware, however, could also be considered as a major drawback. management became easier with the Heatime system. Also 82.2% The last three questions focused on further interest to timely of the farmers strongly agreed or agreed that they saved time util- identify diseased animals, detect rumination activity and monitor izing the Heatime system but only 53.5% confirmed a financial animal health. In a recent study a system for monitoring rumi- nation in dairy cows (Hi-Tag, SCR Engineers Ltd., Netanya, Israel) which incorporates not only an identical accelerometer but also a Conclusion and relevance
rumination monitoring device was validated in dairy cows (27). However, to detect cows close to parturition or sick cows by means The results of this survey demonstrated that the Heatime system is a of daily rumination time further research is required (27). Identifi- well-accepted estrus detection aid, which has the potential to reduce cation of sick cows in the postpartum period has been recognized the time needed for estrus detection and might potentially reduce as important for a swift return of the animals back to a healthy the use of hormones. The data is based on a survey and therefore state (30). About 54.8% of the responding farmers were interested on personal perceptions of the participating farmers. Since science- in such a system. These survey data demonstrate that maintaining based information on the validity of the Heatime system is scarce a dairy cow’s health during the periparturient period is a major more research is required to determine the efficiency.
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I. Michaelis et al.: Estrus detection practices in cattle
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