The effect of the spatial scale of heterogeneity of two herbage species on the grazing behaviour of lactating sheep

The benefits of including clover in sheep pasture are well known, this study investigates a method to enhance these benefits by facilitating diet selection. Lactating ewes and their twin lambs grazed ryegrass (G; Lolium perenne cultivar ‘Parcour’) and white clover (C; Trifolium repens cultivar ‘Kent Wild White’) as either separate or conterminal (G:C) monocultures, or as mixtures (M), at a mean sward surface height (SSH) of 6.6 cm. There were two replicates of each treatment and there were four ewes and their lambs on each replicate. The grazing behaviour of the ewes was measured during an 8-day experimental period. For treatments M and G:C, clover content of the diet was estimated using an n-alkane technique. Ewes on treatments M and G:C selected higher proportions of clover (0.35 and 0.62) than was offered in the paddocks (0.09 and 0.43). The ewes on G:C made frequent transitions between the two herbage species and there was a significant linear increase in this frequency over the day ( P