Diurnal changes in the nutritive composition of four forage species at high and low N fertiliser

Abstract

Chicory and plantain have been suggested as alternative grazed forages to perennial ryegrass for New Zealand dairy systems. While diurnal changes in plant chemical composition have been described for ryegrass there is currently little information for herbs. This experiment aimed to compare the effect of nitrogen inputs (low and high) and harvesting time (am versus pm) on the chemical composition of four forages (ryegrass, plantain, chicory and white clover). The effect of harvest time was greater than N fertiliser inputs on chemical composition for all forages. Ryegrass showed the greatest increase in water soluble carbohydrate diurnally, at the expense of neutral detergent fibre and to a lesser extent crude protein. This suggests afternoon allocation of ryegrass may be beneficial to improve the nutritive value of pasture on offer; allocation timing is less important for white clover, chicory and plantain. Keywords: chicory, clover, crude protein, plantain, ryegrass, water soluble carbohydrate