Diet preferences of herbivores at pasture

Abstract

Preference is the discrimination among sward components displayed by animals when their choice is free. Selection is the picking out of certain sward components rather than others. Testing preferences can help to understand diet selection in more complex environments. We can measure these when the animals are offered different swards provided as turves or trays indoors or forming adjacent homogeneous strips at pasture, and a number of experiments have recently been conducted in this way. In this review, we summarise and discuss what the animals eat given a minimum of constraints. We then focus on how behavioural and vegetation constraints influence diet selection.