Short communication: Comparison of estrus characteristics in Holstein heifers by 2 activity monitoring systems

Abstract

Two activity monitoring systems-Heatime (SCR Engineers Ltd., Netanya, Israel) and IceTag (IceRobotics Ltd., Edinburgh, UK)-were compared on their ability to detect and quantify estrus expression. Holstein heifers (n=57) were fitted with Heatime (HT) and IceTag (IT) sensors from 12 mo of age until confirmation of pregnancy. Upon detection of high activity by HT, ovaries were scanned by ultrasound, a blood sample was collected for analysis of plasma estradiol, and signs of estrus (clear vaginal mucus, uterine muscle tone, visual mounting activity, standing to be mounted, or rump showing signs of repeated acceptance of mounts) were recorded. Because only estrus episodes detected by HT (n=111) were further evaluated, only the positive predictive value was measured. Heifers were housed in groups of 24 in a freestall pen. Data were analyzed using Proc CORR and GLM of SAS (SAS Institute Inc., Cary, NC). The positive predictive value was 84.7% (94/111) for HT and 98.7% (74/75) for IT. Estrus duration was recorded by HT as 14.3±4.1h [mean ± standard deviation (SD)] and by IT as 15.0±4.0h; duration measurements were correlated (r=0.60). The mean duration difference was 0.74±3.52h. Recordings of onset and end of estrus by IT were 3.5±4.3h and 2.9±4.9h earlier than those by HT. The overlap in duration was 9h. Measurements of estrus intensity were correlated (r=0.63). Peak activity was 77.3±19.5 index value (approximately 7.7 SD from basal activity) on HT. The relative increase in activity measured by IT was 360±170% baseline value. Measurements of intensity and duration from HT were correlated (r=0.64) but those from IT were not (r=0.13). Plasma estradiol concentration (11.2±4.6pg/mL) was not correlated with preovulatory follicle diameter or with duration or intensity of estrus. Diameter of preovulatory follicle (15.7±2.6mm) had no correlation with duration of estrus and was only weakly correlated with intensity measured by either system. Baseline steps/hour was negatively correlated with intensity from both sensors (r=-0.37 and -0.70 for HT and IT). Estrus episodes accompanied by 2 or 3 of the monitored signs of estrus had greater intensity and duration on HT but not on IT. Preovulatory follicle diameter and plasma estradiol concentration did not influence occurrence of estrus signs. Results indicate that both systems identified estrus precisely, with correlated characterization and similar timing. In contrast, relationships with plasma estradiol concentration and signs of estrus require further investigation.

Changes of locomotion activity in the Holstein dairy cows during estrus

“…The comparable results of the increased locomotion activity of Holstein dairy cows in the estrus period in comparison with the reference period before estrus were detected also by our research (32.2 %). Significantly higher differences in the locomotion activity, when comparing the period before estrus with the values of this indicator in the estrus period, expressed by the level of the locomotion activity in the interval of two hours (u/2h), were recorded by Favero (1984) and Silper et al (2015) at the level of (77.3 u/2h), or Madureira et al (2013) who detected the average cows´ activity in the estrus period at the level of 72.8 u/2h. Fundamentally different results, based on their experiments, are stated by Firk et al (2002) who did not confirm the significant growth of the cows´ locomotion activity in the estrus period.…”

“…Based on the evaluation of this indicator the system is able to provide to a breeder the basic information about the animal behaviour, their wellbeing and health 24 hours a day, 7 days a week in real time. Therefore the system Heatime RuminAct means for a breeder the modern and unique tool which allows to achieve up 95% accuracy of estrus retrieval, including the identification of the cows´ silent estrus (without outward exhibit sings), (Silper et al, 2015). …”

Automatisierte Fruchtbarkeits- und Gesundheits - überwachung bei der Milchkuh

“…2). Sie registrieren die Halsbewegungen in allen drei Dimensionen (109,141). Weiterhin gibt es Aktivitätsmesser, die an einem Fuß befestigt werden und durch eine 3D-Beschleunigungssensor-Technik sowohl die Schrittzahl pro Zeiteinheit als auch das Steh-und Liegeverhalten des Tieres registrieren.…”

Increasing estrus expression in the lactating dairy cow

“…Activity monitoring systems have increased reading of activity from twice daily (as with pedometers) to 12 or 24 times per day (Løvendahl and Chagunda, 2010). When an AMS (i.e., Heattime) was compared with a pedometer system (i.e., IceTag), the 2 systems had greater precision of estrus detection when compared with visual observation (Silper et al, 2015). Many newer AMS versions measure changes in activity in real time (Silper et al, 2015).…”

“…When an AMS (i.e., Heattime) was compared with a pedometer system (i.e., IceTag), the 2 systems had greater precision of estrus detection when compared with visual observation (Silper et al, 2015). Many newer AMS versions measure changes in activity in real time (Silper et al, 2015).…”