Effect of post-grazing residual pasture height in spring on pasture quality in summer and autumn

摘要

An experiment was undertaken in Waikato, New Zealand, to investigate the effect of post-grazing residual pasture height in spring on subsequent pasture quality. Two target post-grazing residual pasture height treatments were established in spring, 4.0cm (TARGET) and 5.5 cm (HIGH), after which all pastures were grazed to a similar target post-grazing residual height (4.0 - 4.5 cm). HIGH post-grazing residuals in spring resulted in summer and autumn pastures with a lower proportion of perennial ryegrass leaf and pseudostem (0.10; P < 0.05) and ahigher dead material proportion (+ 0.12; P < 0.05). These changes in composition resulted in pastures with a lower organic matter digestibility (-6.1 g 100 g DM~(-1); P < 0.001) in summer and autumn. These results indicate that achieving low-post grazing residuals in spring reduces the dead material proportion in pastures in summer and autumn, resulting in higher digestibility.