Automatic milking and grazing in dairy cattle: effects on behaviour

Milking dairy cattle with an automatic milking system (AMS) can be a reason for a farmer to minimize pasture time during the grazing season, since it is assumed that it may lead to a decrease in use of AMS capacity and an increase in labour required for fetching cows with long milking intervals from pasture. Previous research in The Netherlands showed that grazing in combination with automatic milking can be successful under various management conditions. Knowledge about cow behaviour may reveal useful information in this respect. The aim of this research was to study the effect of grazing combined with automatic milking on the potentially relevant behavioural aspects of a dairy herd. A commercial herd of about 60 cows was observed before and during the grazing seasons of 2001, 2002 and 2003. The cows were milked by an AMS which was introduced in September 2000. Access to pasture was restricted and regulated by a selection gate. Locations in the barn and at pasture and standing/lying positions were observed during 48 h periods using scan sampling with 15 min intervals. Herd behaviour as well as behaviour of 10 selected individual cows showed comparable results. The mean percentage of cows in the AMS was lower during the grazing season than at the end of the winter season, although it was on an acceptable level. No significant differences were found for mean presence in the waiting area in front of the AMS or for the total lying behaviour. These results apply to the management practices used at the farm. Further research on the effect of grazing systems, pasture distances, fetching regimes, cow traffic systems or occupancies of the AMS and their interaction on herd and individual level is needed to optimise the management of dairy cattle offered grazing combined with automatic milking. 1