Effects of contrasting sward heights within forage species on short‐term ingestive behaviour of sheep and goats grazing grasses and legumes

Abstract

Abstract An experiment was designed to separate the effects of sward height on ingestive behaviour, from the confounding effects of forage species and maturity stages which occurred in a previous experiment. Two grass species (perennial ryegrass (Lolium perenne) and cocksfoot (Dactylis glomerata)) and two white clover (Trifolium repens) cultivars ('Grasslands Tahora’ and ‘Grasslands Kopu') with height contrasts within each forage, were grazed at a vegetative stage of growth by four sheep and four goats. Turves (41 × 27 cm) were extracted from the established plots where monoculture swards were growing, and presented after canopy structure was characterised, to animals individually confined in metabolism crates. Animal responses in bite weight, bite rate, and bite dimensions (depth, area, and volume) to variation in sward structure brought about by increases of height within forage species were evaluated. Independent variation of surface height from bulk density was achieved in cocksfoot (r = ‐0.22; P <0.1...