The effect of transferring dairy cows from a group housing system to individual pens for research purposes on behaviour and milk yield

Context. Cows are often subjected to different environmental and handling conditions for research purposes, and it is important to understand potential behavioural changes, as they may influence research outcomes. Aim. To investigate how a transfer from a group housing system to individual pens affected dairy cow behaviour. Methods. Lactating dairy cows (n = 24), housed in an open-sided barn, were transferred to individual pens for 10 weeks. For another experiment's purposes, cows were assigned to a control or an experimental diet. Measurements were taken before transfer (pre), after transfer to the individual pens (early), in the individual pens (late transfer) and on return to the barn (post transfer). Cows' behaviour was assessed every 10 min for 8 h per day, and whether cows were eating, ruminating or idling was recorded. Occurrences of social interactions were recorded continuously during the last 60-s of every 10-min observation. Lying time was recorded using dataloggers. Locomotory ability assessment and daily milk yields were also recorded. Key results. Ruminating and eating time was not affected by diet type, but decreased after transfer to the individual pens. Only eating time returned to pre transfer values at early transfer. Time that control cows spent idling increased in individual pens, whereas the experimental diet cows spent more time idling in the early transfer phase. Social interactions occurred more often during late and post transfer phases. Cow locomotory ability was not affected by the transfer or by type of diet, but total lying time increased from pre to post transfer, the number of lying bouts decreased from late to post transfer phases, and lying bout duration increased as the experimental period progressed. Milk yield gradually reduced over time, and it was affected by the type of diet. Conclusion. Behavioural changes in dairy cows during transfer between housing systems featured adaptive characteristics and did not seem to be detrimental to the major research.