Samenvatting

The last decades, the number of dairy cows per farm has increased and the time spent on individual cows by the farmer has been reduced. To help the farmer detect changes in activity of cows associated with health issues, activity monitoring systems are being developed. The systems can help with daily farm management decisions, thus increasing farm profitability. Besides this economic benefit there is a social benefit: farmers highly value the herd being under continuous surveillance. Nedap Livestock Management (the Netherlands) introduced a leg activity meter and a neck activity collar: Smarttag Leg and Smarttag Neck. By registering activity of individual cows, the Smarttags help the farmer to detect oestrus and give alerts when activity deviates from normal patterns. The objective of this study was to validate results from the Smarttag Leg and Smarttag Neck, by comparing them with results from live observations and video recordings. Eight lactating dairy cows were observed for 22.5 hours each and video recordings were made of six dry dairy cows for 5.5 hours each. Lying, standing, walking, eating, standing up and ruminating were recorded. Data were compared with results from the Smarttag Leg and Smarttag Neck by calculating Cohen’s Kappa, univariate linear regression analysis, Pearson’s correlation and concordance correlation coefficient. Visual observations and video observations show correlation coefficients of >0.85 with the results of the Smarttags for all behaviours except walking. Correlations between visual and video observations and Smarttag results for walking were 0.45 and 0.50 respectively, possibly due to low incidence and difficulties in observing this behaviour. These results provide strong evidence that the Smarttag Leg and Smarttag Neck can reliably be used to monitor specific behaviours. With this system, the farmer can monitor behaviour and detect behavioural changes.