The effect of water soluble carbohydrate concentration of ryegrass on the partial preference of sheep for clover : A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science with Honours at Lincoln University

A preference feeding trial comparing perennial ryegrass cultivars and white clover monocultures was carried out to determine whether ploidy or water soluble carbohydrate (WSC) content would influence the partial preference for clover and ryegrass. Six mixed age Coopworth ewes were housed in individual pens and once a day were offered swardlet monocultures of white clover adjacent to one of three ryegrass cultivars. The ryegrass cultivars were 'Aberdart' (high sugar), 'Bealey' (tetraploid) and 'Bronsyn' (diploid). Before the preference test, one swardlet of each grass cultivar was shaded to prevent the accumulation of sugars over the day and a second swardlet of each cultivar was left unshaded as a means of further testing the effect of WSC on partial preference. WSC concentration did not differ between ryegrass cultivars. But the WSC of shaded grasses was lower (21.0%) than that of unshaded grasses (23.0%) (P=0.06). Shading significantly increased neutral detergent fibre (NDF) from 42.2% to 43.9% (P