Grass growth: Finally we are all back on the same page

Grass growth rates have made a strong recovery – across the country – due to the persistent rain in parts over the last few days.

This has been a very positive result for most, as the lack of rain and low growth rates were beginning to resemble last summer’s drought.

Looking at average grass growth rates for the country, PastureBase Ireland figures are showing average grass growth rates of 79kg DM/ha in Ulster, 75kg DM/ha in Leinster, 73kg DM/ha in Connacht and 73kg DM/ha in Munster.

Although it is important to note that these are just averages and grass growth rates are as high as between 100kg DM/ha and 140kg DM/ha in areas.

However, these high growth rates aren’t without their challenges and as the grass plant enters the reproductive phase, trying to maintain a high level of good grass quality on farms can be difficult.

During the reproductive phase, the grass plant develops a seed head and with that seed head comes a stem.

When this change occurs grass quality deteriorates. If a sward contains a high amount of this poor-quality grass, this can have a negative impact on milk yield.

Throughout the mid-grazing season, every effort should be made to keep grass quality at a high level on the farm.

Maintaining high-quality grass on the farm:
  • Keep pre-grazing yields at 1,400kg DM/ha or less;
  • Cut surplus paddocks as bales;
  • Operate a short rotation of 17-20 days;
  • Meet target residuals (4-4.5cm) to maximise grass quality in subsequent rotations;
  • Reduce supplementation being fed.

Keep an eye on what is ahead of the cows. If the paddock you’re grazing today is heavy, the chances are the next paddock(s) in the rotation will be too.

Perhaps the next paddock in the rotation needs to be skipped to keep your pre-grazing yield at 1,400kg DM/ha.

The trick with surplus paddocks is not to hang around and wait for them to bulk up, they need to be mowed and back into the rotation quickly.

If residuals are not met, topping can be implemented. However, topping is only useful if it is completed correctly. The field should be topped to a height of 4cm and it should be completed immediately after grazing.