Synchronization of ingestive behaviour by grazing dairy cows

Abstract
The synchronization of eating, ruminating and idling activity by lactating dairy cows grazing a perennial ryegrass-white clover sward was studied. Synchronization was defined as the number of pairs of cows engaged in a particular activity as a proportion of the total possible number of pairs and was compared with random expectation using a kappa statistic. All three activities were significantly more synchronized than random expectation. This suggests that wherever possible individual cows should not be treated as replicates in grazing experiments.