Rumination and activity levels as predictors of calving for dairy cows

Abstract

The Australian dairy herd size has doubled over the last 20 years substantially increasing the time that farmers require for individual animal attention to monitor and intervene with events such as calving. Technology will help focus this limited labour resource on individual cows that require assistance. The objective of this experiment was to first determine the profiles of rumination duration and level of activity as determined by sensors between, and within, days around calving and second to use these data to predict the day of calving for pasture-based dairy cows. After 2 weeks from the expected calving date, 27 cows were fitted with SCR HR LD Tags, located in 40×90 m2 paddock and offered ad libitum oaten hay and 2 kg grain-based concentrate/cow per day until calving. Hourly activity and rumination data for each cow, as determined by the SCR tags, were fitted with linear mixed models and all parameters were estimated using restricted maximum likelihood. Rumination duration decreased by 33% over the day prior and the day of calving, with the decline in rumination duration starting the day prepartum. Activity levels were maintained prepartum but increased in the days postpartum. The day of calving was recorded and used to determine the gold standard positive (the day before calving) and negative (all other) dates. A threshold rumination level of 0.9 (decline in rumination duration of 10%) gave the optimal combination of 70% sensitivity and 70% specificity. This experiment shows the potential to use rumination duration to predict the day of calving and the opportunity to use sensor data to monitor animal health.

The utility of sensor technology to support reproductive management on dairy farms

“…A decrease in "rumination" prior to calving was observed in this study, consistent with other studies (Bar and Solomon, 2010, Bucher and Sundrum, 2014, Clark, et al, 2015, Ouellet, et al, 2016, Pahl, et al, Saint-Dizier and Chastant-Maillard, 2015, Schirmann, et al, 2013). In the current study, this decrease was about 15 minutes per hour (the difference between the case and control dataset during the hour in which calving started).…”

“…Previous studies have observed changes in feeding and resting behaviour determined by sensors in the last 24 hours before calving (Bucher and Sundrum, 2014, Clark, et al, 2015, Schirmann, et al, 2013, Titler, et al, 2015. No such effects were observed in the data of the sensor parameters "feeding" and "not active" in the current study.…”

“…It should be noted that these studies generated alerts every two hours instead of every hour and that reduces the total number of alerts including the false positive alerts. Other studies have also reported activity to increase during the 24 hours before calving (Clark, et al, 2015, Miedema, et al, 2011b, Saint-Dizier and Chastant-Maillard, 2015, Titler, et al, 2015. For "temperature", a decrease of about 3°C was observed during the hour in which calving started, whereas other studies have reported decreases in the range of 0.2-0.5 °C (Burfeind, et al, 2011, Ouellet, et al, 2016.…”

“…In the current study, this decrease was about 15 minutes per hour (the difference between the case and control dataset during the hour in which calving started). Clark et al (2015) reported a reduction in rumination of five minutes per hour, whereas Schirmann et al (2013) reported a reduction of 30 minutes per two hours during the last 24 hours before calving. These studies reported their findings on a daily or two-hour basis, which makes comparison difficult.…”

“…Sensors seem capable of detecting these changes (Bar and Solomon, 2010, Bucher and Sundrum, 2014, Schirmann, et al, 2013. Time spent on feeding also decreases, dry matter intake tends to decrease slightly (Schirmann, et al, 2013); (Bucher and Sundrum, 2014), and activity changes in the 24 hours before calving (Clark, et al, 2015, Miedema, et al, 2011b, Saint-Dizier and Chastant-Maillard, 2015. Titler et al (Titler, et al, 2015) demonstrated that an activity index could be used to predict whether a cow would calve in the six hours following an increase in the activity index.…”