Tiller survival
This is the one time of year when ryegrass tillers that have gone through a winter, or 'mother' tillers, produce 'daughter tillers'.
The daughter tillers will become separated from the mother tiller and result in a new plant. Each mother tiller can produce two to three daughter tillers.
Keeping pre-grazing yields between 2600 and 3200kg DM/ha prevents shading, allowing sunlight to reach the base of the plant. This encourages daughter tillers to grow from the plant base, rather than forming above the ground where most won't be able to take root and won't survive.
Supplement use
Good quality ryegrass-based pastures are a well-balanced feed for dairy cows, supplying energy, protein, lipids, vitamins and minerals. Pasture-only is sufficient for production and good reproductive performance.
This means there is little to no benefit to feeding supplements when the farm has a pasture surplus.
Save the supplements for later in the season if the farm gets dry and pasture growth is too slow, or for extending the round when it rains.
Setting up for summer
The third aspect of pasture management in the spring period is ensuring high quality feed is taken into the summer.
On summer dry farms, nitrogen (N) can be applied in late November/early December at 20-25kg N/ha per application (up to 40-50kg N in total) to promote new tiller growth, increase pasture cover and extend the round.
Nitrogen needs to be applied before moisture is limiting growth and will only be beneficial if residual targets of 1500-1600kg DM/ha continue to be met.
Achieving this target consistently is key to controlling the development of reproductive tillers (and emergence of seed heads) which impacts on pasture quality offered at the next grazings.
Extending the round is also important because as moisture becomes limiting, the rate at which new leaves emerge slows down.
A longer round allows the 2 to three leaf target to still be met, ensuring maximum growth is achieved before grazing, consequently achieving greater annual pasture yields.