Effect of feeding space on the inter-cow distance, aggression, and feeding behavior of free-stall housed lactating dairy cows.

The objectives of this study were to determine whether doubling the amount of feeding space from 0.5 to 1.0 m per cow leads to increased spacing between cows at the feeder, fewer aggressive social interactions among cows, and ultimately increased feeding activity. Twenty-four lactating Holstein cows were provided with 0.5 and 1.0 m of feeding space per cow in a 2 x 2 crossover design replicated over time. Time-lapse video was used to quantify the inter-cow distance and incidence of aggressive displacements at the feed alley. An electronic feed alley monitoring system was used to monitor the feeding behavior of the cows. When animals had access to 1.0 m per cow, there was at least 60% more space between animals and 57% fewer aggressive interactions while feeding than with access to 0.5 m of feeding space. These changes in spacing and aggressive behavior in turn allowed cows to increase feeding activity throughout the day, especially during the 90 min after providing fresh feed (an increase of 24%). This increase in feeding activity was particularly evident for subordinate cows. These results indicate that increasing space allowance at the feeder increases feeding activity and reduces competition among lactating dairy cows.