In organic laying hens husbandry it is desirable that the animals cover a proportion of their daily fodder intake by foraging in the outside run, e.g. by grazing. So far, however, few studies have investigated the factors which influence herbage intake of laying hens. In the present experiment we analysed the foraging behaviour of laying hens in the outside run at different conditions of sward botanical composition and of percentage ground cover of vegetation. The animals were taken to pasture on monocultures and a mixed plot of fourteen grassland plant species for three levels of period of stay in a rotational grazing system. By means of point sampling, we recorded scratching, plant pecking and ground pecking. Our results indicate that the factor plant species per se is a weak determinant of the animals’ foraging behaviour. However, the tested plant species showed varying persistence at prolonged duration of stocking. Percentage ground cover of vegetation had a significant positive correlation with plant pecking and was negatively correlated with ground pecking. At a ground cover of less than 60 %, the frequency of plant pecking strongly decreased
