Pasture
Heading date is when a paddock visually has 50% of the plants seed heads emerged. Heading dates are defined relative to the cultivar Nui, heading at day 0.
Aftermath heading refers to the number of seed heads produced after the main heading event. If there are a lot of seed heads produced after the main heading event (high aftermath heading) then this means pasture quality is reduced. If there are minimal seed heads produced (low aftermath heading) then pasture quality is maintained for longer.