Are cows more likely to lie down the longer they stand?

Information on (changes in) standing and lying behaviour of cows can be used for oestrus detection, early diagnosis of disorders and to evaluate welfare consequences of changes in housing and management. Data sets on lying and standing behaviour were collected from cows with IceTag™ sensors fitted to the leg. Data were obtained with 10 late-pregnant indoor-housed beef cows (Exp. 1), 19 out-wintered beef cows (Exp. 2) and 44 housed lactating dairy cows that were milked three times daily (Exp. 3). During part of Exp. 1 video footage was recorded to validate the sensor records. Data were analysed with the aims of estimating objective lying and standing bout criteria and to test two hypotheses. These hypotheses were that (i) the probability of cows standing up would increase with the length of time the animal had been lying down and (ii) the probability of cows lying down would increase with the length of time the animal had been standing. A total of 10,814, 39,089 and 9405 lying episodes were recorded by the sensors in Exp. 1–3, respectively. On the basis of log–survivorship plots, frequency distributions of (log-transformed) lying episode lengths and analysis of the correspondence between recorded lying episodes and video footage of lying behaviour, a minimum lying bout criterion of 4 min was indicated. Application of this criterion reduced the number of lying episodes by between 62% and 88% in the three experiments, even though this had only minor effects on total estimated lying and standing time (changes between 0.5% and 3.2%). Out-wintered beef cows tended to have fewer but longer lying bouts than the other groups and dairy cows had the shortest total lying time. (11.6, 10.5 and 10.2 h/day in Exp. 1–3, respectively). The probability of cows standing up within the next 15 min increased (P < 0.001) with lying time in all experiments, which was consistent with the first hypothesis. The probability of cows lying down within the next 15 min did not significantly increase with standing time. This lack of change in probability was not caused by pooling of data across day and night or across cows with different behavioural strategies. Our second hypothesis was, therefore, refuted because cows were not more likely to lie down the longer they had been standing.