THE INFLUENCE OF RESTRAINT ON THE OCCURRENCE OF ORAL STEREOTYPIES IN DAIRY-COWS

Sixteen dairy cows with stereotypies (i.e. movements that are repeated regularly without any obvious function) consisting of tongue-rolling, sometimes combined with bar-biting, were exposed to three different treatments: Group A was tethered in stalls after a 4-month grazing period, Group B remained tethered inside the stable during the normal grazing period, and Group C was tethered for 8 months and then transferred into loose housing. The duration of the stereotypies and the frequency of adjoining behaviours were registered in Groups A and B from the first week after the tethering of Group A and for the next 8 weeks. In Group C, the duration of stereotypies was registered when they were tethered and after they had been transferred into loose housing. Group A showed a marked behavioural response to the tethering, with the highest levels of stereotypies during the first 3 weeks after tethering, and thereafter a marked decrease. Groups A and B had significantly different stereotypy levels 2-6 weeks after tethering (P=0.035). In Group C, five of six cows stopped performing stereotypies after the transfer into loose housing, while one cow which previously showed high stereotypy levels continued at a very low level, from 25.7% when tethered to 0.6% in the loose housing (of total observation time). These results indicate that the tethering of dairy cows has negative implications on their welfare.