The effects of reducing manger space on dairy cow behaviour and production

The manger space for a group of 30 cows was reduced from 105 cm to 15 cm per cow during a period of six weeks. Before each reduction in manger space the cows were observed for 24 hours and their activity and aggressive behaviour recorded. The activity of individual cows varied little but there was wide variation among cows. The reduction in manger space did not change the mean number of visits by cows to the manger, the total time spent feeding, the amount of aggressive behaviour, the milk yield or the general activity of the cows in comparison with a control group allowed 105 cm of manger space per cow for the whole period. There was a reduction in the total time spent feeding by cows which were clinically ill and a change in the number of visits made to the manger by cows in oestrus. A reduction in the allocation of manger space would make it possible either to build smaller, cheaper housing or to convert existing buildings to accommodate more cows. It would also make it possible to use automated systems to record the feed intake and number of visits to the manger of individual cows and would help to detect cows which were sick or in oestrus.